A SYSTEM OF 
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Section 11-BONES and JOINTS. 
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1882. DUNGLISON, ROBLEY, M. D. 
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HUMAN ANATOMY. 
BONES -D JOINTS. Entered according to the Act of Congress, in the year 1882, by 
HENRY C. LEA'S SON & CO., 
in the Office of the Librarian of Congress. All rights reserved. CONTENTS 
PAGE 
The Lumbar Vertebrae ..... 115 
Remarks on the Vertebral Column as a Whole . 116 
The Sacrum . . . . . . .117 
The Coccyx . . . . . . .119 
The Bones of the Head 119 
The Occipital Bone . . . . . .119 
The Temporal Bone . . . . . .122 
The Sphenoid Bone . . . . . .125 
The Parietal Bone . . . . . .128 
The Frontal Bone ...... 129 
The Ethmoid Bone . . . . . .131 
The Vomer ....... 132 
The Superior Maxilla . . . . .133 
Palatal Bone ....... 136 
Inferior Turbinated Bone . . . . .137 
Malar Bone . . . . . . .137 
The Lachrymal Bone ..... 138 
The Nasal Bone . . . . . .138 
The Inferior Maxilla . . . . .139 
The Skull 144 
The Cranium . . . . . . .144 
The Cranio-Facial, or Intermediate Portion of 
the Skull ....... 151 
The Face ....... 152 
The Skull considered in Relation to Age . . 157 
The Hyoid Bone ...... 158 
The Ribs ........ 159 
The Costal Cartilages . . . . .161 
The Sternum . . . . . . .162 
The Thorax . . . . . . .164 
The Bones of the Upper Extremity . . . 166 
The Clavicle . . . . . . .166 
THE BONES. 
PAGE 
General Considrations ..... 97 
Origin of Bones ..... 97 
Cartilages ....... 97 
Number of Bones ..... 97 
Classification of Bones ..... 98 
The Long Bones ..... 98 
Flat Bones ...... 98 
Irregular Bones ..... 98 
Sesamoid Bones ..... 98 
Wormian Bones (Ossa Triquetra) . . 98 
Weight of the Skeleton .... 98 
Terms Used in Describing Bone ... 98 
Properties of Bone ..... 99 
The Cancelli ...... 99 
Peculiarities of the Living or Fresh Bone . 100 
Medulla ....... 101 
Fresh Bone . . . . . .101 
Dry Bone ....... 101 
Chemical Analysis . . . . .101 
Identification of Bones for Medico-Legal Pur- 
poses ........ 102 
The Vertebra: ....... 106 
The Vertebral Column ..... 106 
Development . . . . . . .110 
The Cervical Vertebra: 110 
The Atlas . . . . . . .Ill 
The Axis . . . . . . .112 
The Seventh Cervical Vertebra . . .113 
The Dorsal Vertebra: ..... 114 
III IV 
CONTENTS. 
PAGE 
The Scapula . . . . . . .169 
The Humerus . . . . . . .173 
The Ulna 176 
The Radius . . . . . . .177 
The Carpus ....... 179 
The Metacarpus . . . • . .181 
Phalanges . . . . . . .182 
The Bones of the Inferior Extremity . . 183 
The Innominate Bone ..... 183 
The Pelvis ....... 186 
The Femur ....... 189 
The Tibia 192 
The Fibula ....... 194 
The Patella ....... 196 
The Bones of the Foot . . . . .197 
The Tarsus . . . . . . .197 
The Metatarsus . . . . . .201 
The Phalanges ...... 202 
The Foot ....... 202 
THE JOINTS AND THE LIGAMENTS. 
General Considerations 205 
On the Action of Joints ..... 206 
The Joints and Ligaments of the Trunk . . 212 
The Joints and Ligaments of the Vertebral 
Column 212 
The Temporo-Maxillary Joint .... 215 
The Joints and Ligaments of the Thorax . .216 
The Ligaments of the Superior Extremity . 217 
The Claviculo-Sternal Joints and Ligaments . 217 
PAGE 
The Joint and Ligaments of the Shoulder . . 219 
The Ligaments of the Scapula . . • .219 
The Scapular Attachments of the Clavicle . 219 
The Shoulder-Joint ...... 220 
The Elbow-Joint and Ligaments . . .221 
The Ligaments of the Radius and the Ulna . 223 
The Interosseous Membrane .... 223 
The Inferior Radio-Ulnar Joint . . . 223 
The Wrist-Joint ...... 223 
The Joints and Ligaments of the Hand . . 224 
The Carpo-Metacarpal and the Inter-Metacarpal 
Joints and Ligaments ..... 225 
The Metacarpo-Phalangeal Joint . . . 225 
The Inter-Phalangeal Joints and Ligaments . 226 
The Joints and Ligaments of the Lower Ex- 
tremity ....... 226 
The Joints and Ligaments of the Pelvis . . 226 
The Ilio-Sacral Joint ..... 226 
The Symphysis Pubis ..... 227 
The Sacro-Coccygeal Joint .... 228 
The Hip-Joint ....... 228 
The Knee-Joint ....... 230 
The Tibio-Fibular Articulations . . . 234 
The Ankle-Joint ...... 235 
The Joints and Ligaments of the Foot . . 237 
The Joints and Ligaments of the Tarsus . . 237 
The Joints and the Ligaments between the Tar- 
sus and the Metatarsus ..... 240 
The Inter-Metatarsal Joints and Ligaments . 240 
The Joints and Ligaments between the Meta- 
tarsus and the Phalanges .... 241 
The Inter-Phalangeal Joints and Ligaments . 241 D E S C RIP T IVE A N A T 0 M Y 
T H E BONES. 
ossify, and is decreased as the osseous centres unite one 
with another. Authors do not agree as to the number 
of bones in the body, since the age at which the bones 
should be counted has never been agreed upon. 
Hyrtl makes the number of bones in the skeleton 
240, Leidy, 214, Ward, 206, Quain, 200, Sappey, 198. 
In order that intelligent comparison may be made 
between the numbers above given and the number 
adopted for this work, the bones are enumerated with 
some detail in the following order:- 
Spine ......... 24 
Skull 22 
Small bones of the ear ..... 6 
Neck (Hyoid) ....... 1 
Ribs ......... 24 
Sternum ........ 1 
Shoulder girdle (including scapulas and clavi- 
cles) ........ 4 
Superior extremities 60 
Sesamoids of same, excluding the pisiforms . 4 
Pelvic girdle (including the hip-bones, sacrum, 
and coccyx) ....... 4 
Inferior extremities (excluding the patellae) . 58 
Sesamoids of lower extremities (including patellae) 6 
214 
Of these, the occipital bone, sphenoid bone, ethmoid 
bone, frontal bone, and bones in the skull, and the 
sternum, hyoid bone, vertebral column, sacrum, and 
coccyx are unpaired. 
The study of the development of the bones will 
modify the above conclusions both as to number and 
GENERAL CONSIDERATIONS. 
The skeleton is an assemblage of bones and carti- 
lages joined together to form the framework of the 
body. Its several parts serve to protect the viscera, 
and to act as organs of passive locomotion. 
A skeleton, as preserved in the cabinet, is said to 
be natural when the bones and cartilages are held in 
their natural relations by means of ligaments. It is 
said to be artificial when the ligaments have been re 
moved, and wire and leather, or other materials, are 
substituted for them. 
Origin of Bones.-The bones of the skeleton arise 
from cartilage for the most part; such are often 
named, from this fact, cartilage bones. Bones not 
arising from cartilage develop from fibrous tissue; 
such bones are known as membrane bones, since they 
for the most part appear in membranous expansions. 
The parietal and frontal bones belong to this group. 
Cartilages.-The cartilages of the body, while 
preserving their integrity, aid in resisting shocks and 
maintaining elasticity. Cartilage is called permanent 
when it presents no tendency to ossification, and tem- 
porary when it possesses a tendency to turn into 
bone. 
Number of Bones.--The number of bones in the 
body varies according to the age of the subject. The 
number is increased as the several temporary cartilages 
97 98 
THE BONES. 
symmetry. It may be stated once for all that the 
facts given are intended to apply to the adult skeleton, 
and to the purposes of the physician, and not to 
satisfy the needs of the student of morphology. 
f 
CLASSIFICATION OF BONES. 
The bones comprising the skeleton are classified 
either by the region of the body in which the bones 
occur, as those of the head, chest, extremities, etc., or 
by the shapes of the bones themselves, when the 
terms long, flat, irregular bones, etc., are used. 
The Long Bones.-The long bones are those 
which resemble for the most part modified cylinders. 
Hence, they are often called cylindrical bones. They 
are prismoidal in shape, and slightly twisted. The 
femur or thigh-bone, the tibia or shin-bone, the fibula 
or clasp-bone, and the analogous bones in the arm 
and forearm, are good examples of the class. Long 
bones of a smaller kind than the foregoing arc often 
classified as the short bones. Among these may be 
placed the clavicles or collar-bones, and the metacar- 
pal and metatarsal bones. They are less prismoidal 
than the long bones proper. The phalangeal bones, 
which belong to the same class, are flat on one side, 
and thus recall the figure of a semicylinder. 
Each long bone presents a shaft or diaphysis, and 
two extremities. The shaft slightly expands to join 
the extremities. These form the bases of two pyra- 
mids, the apices of which may be said to unite in 
the shaft. In the bones of a prismoidal form the 
sides of the prism-like figure extend into the extremi- 
ties, and serve to strengthen them. The extremities 
of a long bone articulate with the adjacent bones, and 
ordinarily form what is known as epiphyseal ends, 
owing to the fact that these portions of the bones 
arise from distinct centres, known as the epiphyses. 
The ligaments are here attached, the muscles have 
insertions, and the surfaces are marked by rugosities 
and venous canals. 
The end of the bone nearest the body is called 
the proximal end, and that farthest away the distal 
end. When an articular surface is round and convex 
(especially if it is on the proximal extremity), it is 
called the head of the bone. The neck is a contrac- 
tion placed beneath the articular surface, and is apt to 
be the narrowest part of the bone. No muscle is 
inserted either upon the head or the neck of a bone. 
Flat Bones. - The flat bones are irregular and 
tablc-like, and ordinarily arc passive in their function. 
Such, for example, are the bones of the skull which 
protect the brain, and those of the pelvis which pro- 
tect the internal organs of generation and in part the 
intestines. An important flat bone, the scapula, is 
however active in its function. 
Irregular Bones.-The irregular bones are of 
small size, and do not preserve any constant outline. 
In this class are placed the bones of the carpus and 
tarsus, and those of the vertebral column. Some 
are placed in pairs, while others are median and 
single. They agree in function, however, since they 
are always found in situations where strength and a 
slight motion are required. They are thus admirably 
adapted to sustain weight and to resist shock. 
The irregular bones are arranged in a single row as 
in the vertebral column, or in a number of rows as 
in the carpus and tarsus, primarily in the longitudinal 
direction of the limbs, but forming at the same time 
transverse arches of enormous strength. 
Sesamoid Bones.-The sesamoid bones arc so 
named from their resemblance to seeds. They are 
rounded or oblong ossifications of small size arising 
in the tendons of muscles, and aid these organs in 
maintaining accurate relations to articular surfaces. 
They are thus seen in muscles crossing joints, as the 
quadriceps femoris and flexor brevis pollicis. They 
ordinarily possess one or two articular facets. 
Wormian Bones (Ossa Triquetra).-The Wor- 
mian bones are tabular. They are inconstant, of vari- 
able size, and are seen nowhere but in the vertex of 
the skull. They belong to the group of bones here 
situate, and are firmly articulated with them. They 
are apt to be seen between the parietal and the occi- 
pital bones. 
Weight of the Skeleton-The skeleton weighs 
from twelve to fourteen pounds. The right side is 
somewhat heavier than the left. 
TERMS USED IN DESCRIBING BONE. 
In the description of bones a number of special 
terms occur, some consideration of which is neces- 
sary to a proper understanding of the text. Among 
those relating to distinctions among the kinds of ele- 
vations or prominences from the common surface of 
a bone, may be mentioned the following:- 
Process.-Any projection from the bone. 
Condyle.-An articular process of bone, which is GENERAL CONSIDERATIONS. 
99 
large, and as a rule convex. Upon the tibia, the 
condylar surfaces are slightly concave. 
Tuberosity.-A large rounded process. 
Trochanter.-A tuberosity which serves for mus- 
cular attachment in positions favorable to rotatory 
motion. 
Spine.-A pointed process. 
Crest.-A pronounced ridge-like elevation. 
Line.-An elevation less pronounced than a crest. 
Every bone presents surfaces, borders, and angles. 
These terms will frequently recur in the descriptions. 
Among the depressions on the general surface of 
the bone may be mentioned the following:- 
Fossa.-A deep saucer-shaped depression. It may 
be articular, as the glenoid fossa ; or muscular, as the 
iliac fossa. A digital depression is a circular shallow 
fossa. 
Groove or Sulcus.-A narrow elongated depres- 
sion. 
Furrow.-A relatively broad, shallow groove. 
Fissure.-A narrow chink. It often answers to 
lines of defective union between different bones. 
Fissures are most commonly seen in the skull. 
Meatus.-A sulcus or canal leading to parts other 
than those defining the meatus. The meatus of the 
nasal chamber is a depression on the lateral wall of 
the nasal chamber leading to the pharynx; the ex- 
ternal meatus is a tubular passage made up of the 
squama and tympanic bone, leading to the middle ear. 
Sinus.-An open cavity with a narrowed mouth 
lined with mucous membrane. 
The flexor surface and the extensor surface 
of a bone are terms often employed in the same sense 
as ventral and dorsal. See Definitions in Introduction, 
p. 20. 
The openings in bone are known as- 
Canals.-When they form tubular passages into 
or through bones. 
Foramina.-When they form simple openings of 
transmission. 
Properties of Bone.-Bone is the firmest and 
hardest of the tissues, enamel alone excepted, and is 
especially designed to combine great strength with 
lightness. Elasticity is one of its most conspicuous 
properties. The form of the bone aids in maintaining 
it, as in the rib and the lower jaw; but all the bones 
possess it in more or less degree. Bone-tissue is either 
compact or spongy. When compact, it possesses firm- 
ness to a high degree, and when spongy, lightness. 
Compact bone is best seen in the lines adapted to 
bear the greatest resistance and sustain the greatest 
weight; the spongy is best seen in places where light- 
ness and facility of motion or delicacy of use are the 
purposes required. Most of the long bones are hol- 
low, and, as already mentioned, are termed cylindrical 
bones. This form aids greatly in maintaining light- 
ness without sacrificing strength, the wall of 'the 
cylinder being composed of compact bone, while the 
hollow space is filled with a form of fatty tissue (p. 56). 
The Cancelli.-The extremities of a bone are, on 
the other hand, solid in the sense of being without a 
central cavity, and are composed of reticulations of 
minute plates and rods of bone, which are collectively 
termed the cancelli. The cancellous, or spongy tissue, 
as it is indifferently termed, is admirably adapted to 
break the jar of a sudden blow, and to prevent it from 
reaching the delicate central structures of the body. 
Each bone exhibits a special arrangement of the can- 
celli, the one specially adapted to its necessities, and 
no two bones, or, indeed, no two parts of a single 
bone, preserve exactly the same arrangement. 
In studying cancelli it will be seen that the stoutest 
laminae, and the best mechanical disposition for sustain- 
ing weight and distributing force exist in the positions 
where the necessities for such properties are the 
greatest. As a consequence, it is evident that, while 
a general resemblance exists between the cancelli of 
bones of a natural group, as, for example, those of 
the vertebral column, or the ends of long bones near 
joints which resemble one another, great contrasts 
are exhibited in other bones having highly specialized 
lines of work to perform, such as the astragalus, the 
calcaneum, and the femur. 
Cancelli naturally arrange themselves into those of 
the articular epiphyses, of the muscular epiphyses, of 
the ossified articular cartilages, and, in the main, into 
pillars and laminae of the shafts of the bones. For 
convenience these subdivisions are not described 
separately, although each should be taken up by itself 
in special studies of any single bone. 
The physical properties of bone are capable of 
being modified by the peculiarities of each of the 
bones, and will of necessity vary in the performance 
of different lines of work. The petrous portion of 
the temporal bone is naturally hard and brittle; the 
tarsal and carpal bones are spongy, and not inclined 
to fracture. The former has no superimposed weight 
to sustain ; the latter have important relations to bear 
while supporting the entire body in the erect position. THE BONES 
100 
The same differences may be noted in the various 
parts of a single bone. The differences in the rela- 
tions of the cancelli and the compact matter in this 
way furnish clews to the significance of delicate 
mouldings, curves, lines, ridges, or of the general pris- 
moidal or tubular shape of a bone; these are, indeed, 
so many accessories of structure, and aid the bone in 
developing to the best advantage its special phases of 
elasticity, lightness, strength, etc. It would be going 
too far into the obscure subjects of teleology, the laws 
of heredity, or the question of primal adaptation 'of 
structure to a preconceived design, to pursue this 
subject further. But this much may with certainty 
be said, that the general properties of bones, and 
indirectly their shapes and special uses, are largely 
determined by traction, pressure, or other familiar 
expressions of force.1 
When a sequestrum forms in the cancellous struc- 
ture, the bone in the vicinity becomes more compact. 
The sequestrum itself is somewhat more compact 
toward the centre than toward the periphery. 
Peculiarities of the Living or Fresh Bone. 
-A bone when examined in its living condition is 
covered with a membrane called the periosteum, which 
is continuous with the tendons of the muscles in- 
serted into the bone. In a strict sense muscles are 
inserted into the periosteum of the bone rather than 
in the bone itself. In the fresh condition the peri- 
osteum can with care be raised from the bone. It is 
thus seen as a thin fibrous membrane of a pearly- 
white color and firm consistence. In inflammation 
of the bone the periosteum becomes greatly thick- 
ened, and can be detached with ease. The perios- 
teum is not a simple fibrous membrane, as a super- 
ficial examination would indicate. While its outer 
surface is plainly fibrous, its inner surface where it lies 
in contact with the bone possesses bone-producing 
power. The importance of a knowledge of these 
facts in surgical practice cannot be over-estimated. 
The ease with which the removal of inflamed peri- 
osteum can be accomplished explains the presence of 
a.blood-clot between the periosteum and the bone in 
the course of ostitis or periostitis. It also accounts 
for sub-periosteal abscess, and the rapidity with which 
an abscess of this kind may develop. The special 
value of the periosteum in aiding and maintaining 
bone-growth being remembered, the presence of a 
clot of blood or a layer of pus will be seen to with- 
hold from the bone beneath its normal supply of 
blood, and the shaft of the bone may die for a dis- 
tance corresponding to the area of denudation. In 
this way necrosis of the shaft of bones is explained. 
A knowledge of the above conditions enables the 
surgeon to strip up the membrane from the ends of the 
bony fragments he wishes to excise without injury 
to it. It is evident that the detachment of the peri- 
osteum must bear some relation to the condition both 
of the membrane and of the bone itself. The peri- 
osteum is more readily detached in growing subjects 
than in the adult, in chronic inflammation than in 
acute, and to a greater degree in some bones than in 
others. 
The lower jaw, the clavicle, the bones of the forearm 
and arm would appear to present in the human sub- 
ject unusual facilities for denudation, with relatively 
slight impairment of the vitality of the membrane, 
if the success attending operation on these bones 
serves in any way as a standard for comparison. The 
greater part of the shafts of these bones has been 
removed, and new bone has formed in its place through 
the agency of the periosteum. The other bones pos- 
sess the property in a much less degree,-such as the 
bones of the lower extremity, and the flat and irreg- 
ular bones generally. This property appears to be 
almost entirely absent in the bones of the brain-case. 
Bone, while owing much of its genetic power to the 
periosteum, is not dependent thereon, but is indebted 
measurably, according to Dr. Alex. Ogston,1 to the 
cartilage covering the articular surfaces. In the 
judgment of this observer articular cartilage is as 
valuable and necessary in forming and maintaining 
the structure and shape of bone as is the periosteum. 
He believes that there is a peculiar structure of the 
bone in this way produced which permits of its being 
readily distinguished from that of periosteal origin. 
"The former variety is marked out," he informs us, 
"by the main beams or trabeculae of its mesh-work 
being placed at right angles to the bone surface, while 
periosteal bone is characterized either by its main 
trabeculae being parallel to the bone surface or by 
there being no indication of any special direction ob- 
servable in them at all." 
Periosteum may be torn away from the bone to 
which it is attached by violent injury. In com- 
1 The trabeculae differ in such slight degrees in different 
localities that it has been customary to include them in a simple 
description of each bone. This plan will be pursued in this work. 
At the same time the student is advised to study the sawed 
section of bone, for in no other way can the nice points of resist- 
ance and pressure as expressed in the details of bony structure be 
appreciated. 
' Journ. of Anat, and Phys., 1878, 503. Numerous illustrations. GENERAL CONSIDERATIONS. 
101 
minuted fracture, portions of bone of variable size 
are thus denuded, and suffer from atrophy or death 
in consequence. Mr. Annandale1 reports an instance 
in which the periosteum had been stripped from the 
patella in a case of rupture of the patellar ligament. 
In some forms of dislocation an analogous lesion oc- 
curs ; such, for example, is the elevation of the strong 
layer of periosteum covering the posterior surface of 
the sternum in displacements of the manubrium upon 
the gladiolus,-the lower end of the former lying 
behind the upper end of the latter.2 
Medulla.-The interior of the bone is occupied 
by a peculiar fatty substance which has received the 
name of the medulla. The membranous surfaces of 
the medulla, which lie in contact with the bone, have 
been often spoken of collectively as the endosteum, 
although such a membrane cannot be separated from 
the medulla. The spongy ends of the long bones, and 
the interior of the flat and irregular bones, do not 
possess the fatty medulla, but in its place there is a 
reddish flesh-like substance occupying the interstices 
of the cancelli, which, under the microscope, resolves 
itself into large nucleated cells. It is from this tissue 
that the fatty medulla has originated, since we find 
in the bones of the infant that the medullary cavity 
and the fatty medulla are absent, and that their 
places are occupied by the same tissue which is seen 
throughout late childhood and adult life in the ex- 
tremities alone. 
Fresh Bone.-The fresh bone is found to be of a 
faint yellowish-pink or bluish yellow color, the de- 
gree of bluish tinge being determined by the condi- 
tion of the circulation at the time of the death of the 
individual. In deaths from drowning, or in analogous 
states in which the blood has become largely sur- 
charged with carbonic acid, the bones are bluer than 
in deaths from other causes. The yellow color is due 
to the effect of the presence of the fluids in the body 
and the fatty medulla upon the white color of the 
osseous tissue. Bones of the young subject are more 
uniformly red than those of the adult. 
Dry Bone.-When the blood, fat, membrane, and 
cartilage are removed from a bone, as, for example, 
by maceration, the color becomes white. In this 
condition the bone is porous. All the interstices and 
the canals leading thereto are freely continuous with 
one another; the bone thus absorbs fluid readily, and 
will permit a column of mercury to pass through it 
as through a sieve, from end to end. 
The outer surface of the well-developed long bone, 
as the femur and humerus, is found to be marked by 
minute elevations, with intervening linear depressions, 
while here and there over the surface of the bone are 
small, flat, whelk-like nodules. 
The surfaces are also pitted by innumerable minute 
orifices for bloodvessels, and near the extremities 
by larger ones (mostly for veins) opening from the 
bottom of the large depressions there present. The 
main nutritive canal of the long bone enters in some 
part of the shaft, and passes obliquely into the me- 
dullary cavity. The direction of this canal varies in 
the different bones. In the ulna, radius, and femur it 
is directed upward ; and in the tibia and humerus it is 
directed downwards. 
The dry bone, when exposed for a long time to the 
atmosphere, splits into lamime. It is thus proved that 
the osseous tissue is laminated, and not homogeneous 
in structure. 
Chemical Analysis. - Bone when subjected to 
chemical analysis yields fl- 
Calcium carbonate 7.05 
Magnesium phosphate ...... 2.08 
Calcium phosphate 58.39 
Calcium fluoride . . . . . . .2.25 
Organic matter 30.23 
100.00 
Thus nearly one-third of the component parts of 
bone is composed of organic, and the remaining two- 
thirds of inorganic substances. 
If bone be subjected, to the prolonged action of an 
acid,2 the inorganic substances arc dissolved, leaving 
the organic unchanged. The form of the bone by 
this procedure is preserved, but its consistence is 
fibrous merely, and its strength and rigidity are lost. 
Such a specimen can be bent in any position by mode- 
rate force, and in the case of the fibula can be even 
tied in a knot. 
If, on the other hand, the organic portions be re- 
moved, by subjecting a bone to the action of fire (as 
in a furnace), the organic matters are destroyed by 
burning, and the inorganic portions only are left. 
The form of the bone, as in the other procedure, is 
1 Gorup-Besanez. Anleitung zur Qualitativen und Quantitativen 
Zoochemischen Analyse, 1871, 420. 
2 For this purpose a solution of hydrochloric acid in water may 
be prepared, having a strength of one part of acid to sixteen of 
water. The fluid should be renewed daily. 
1 Edinburgh Med. Journal, 1875, 838. 
2 W. Rivington, Med. Chir. Trans., Ivii. 102. 102 
THE BONES. 
preserved, but the elasticity and the toughness are 
destroyed. The bone is thereby made preternaturally 
brittle, since it is composed entirely of bone-salts 
and ash. 
The living bone with a deficiency of organic mate- 
rial is thus too brittle, as one with a deficiency of in- 
organic material is too yielding. The mean between 
these extremes results in the normal property of bone. 
This mean varies, however, according to age. The 
bone of the infant, with its want of medullary canal 
and small proportion of bone-salts, while admirably 
adapted to a state of development, would be the 
source of serious disadvantage in the adolescent or 
adult. In old age the bones become more brittle, 
owing to the loss they sustain in a diminution of 
their organic materials. 
IDENTIFICATION OF BONES FOR MEDICO-LEGAL 
PURPOSES. 
Courts of justice not infrequently demand expert 
testimony upon the nature of bony fragments sub- 
mitted to examination, or upon the presumed pecu- 
liarities of the missing portions. Are the bones 
human? Do they belong to one individual? What 
was the sex, age, or height of the individual? Are 
the bones healthy or diseased ? Do they show the 
effect of previous, recent, or old injury ? Can the time 
since death be determined by examination of the 
fragments ? 
The propositions embraced in such questions ne- 
cessarily involve many difficulties, most of which, 
however, can be readily overcome. In most cases 
special study of the suspected part can alone be 
relied upon in arriving at a decision, since the indi- 
vidual variations of bones prevent the following of 
fixed rules, no matter how carefully they may have 
been prepared. 
The bones of the opposite sides of the body, while 
bearing a close resemblance to one another in general 
shape and in the relative development of the details of 
structure, will be often of different lengths. This fact, 
which tailors and shoemakers have observed from time 
immemorial, has awakened of late years professional 
interest. 
Dr. Wm. Hunt1 called attention to the fact that 
in the human body the lower limbs are of different 
lengths. According to the measurements of Dr. W. 
C. Cox,1 this difference exhibits a range of from one- 
eighth to one-half of an inch. Dr. J. S. Wight,2 in a 
subsequent series of observations, arrived at similar 
conclusions. Dr. Jeffries Wyman3 had previously de- 
termined that the clavicles and ulnas differ in length. 
In endeavoring to determine the sex of the indi- 
vidual, it must be borne in mind that the pelvis is the 
most characteristic portion of the skeleton, and that the 
difficulty of determining the point is rendered greater 
both before and after the child-bearing period. The 
well-known differences between the male and the fe- 
male pelvis need not be repeated here. It will be 
observed that the bones of the female are smoother, 
smaller, and more delicate than the corresponding 
bones of the male. According to Sappey, the skull 
of the female is longer as compared to its breadth 
and height than is that of the male. The manubrium 
of the sternum in the female, according to Hyrtl, ex- 
ceeds in length that of half the body of the bone; 
while in the sternum of the male the body is at 
least twice as long as the manubrium. Dr. Thomas 
Dwight4 showed that this rule, like most of its kind, 
is open to many objections. Yet one-half of the 
specimens measured by this observer confirmed the 
statements of Hyrtl. 
The bones of young subjects may be distinguished 
by the epiphyses remaining ununited with the shafts. 
The surface of the bone in contact with periosteum 
is less smooth than in the adult, and may present 
the appearance of the periosteum having been vio- 
lently detached. The vascular openings are rela- 
tive!/ large and numerous. The jaws are more or 
less occupied by developing teeth. Bones from an 
aged individual are either thinner or thicker than 
in the young adult. The outer wall of the orbito- 
temporal septum is thin and often diaphanous. The 
depressions in the bones of the cranial vertex for the 
Pacchionian bodies are deeper. 
With regard to the readjusting of detached portions 
of a skeleton Meyer gives the following rule for plac- 
ing the pelvis in its approximately correct position: 
Bring the anterior superior spines of the ilia and 
the spines of the pubes into the same vertical plane. 
This writer finds that a line running from the upper 
surface of the symphysis pubis to the transverse de- 
pression in the third sacral vertebra will form an 
1 Am. Journ. Med. Sei., April, 1875, 438. 
2 Archives of Clinical Surgery, Feb. 1877, 283; Proc. Med. Soc. 
County of Kings, N. Y., Jan. 1878, 338. 
3 Proc. Boston Nat. Hist. Soc. xi., 1868, 246. 
4 The Identification of the Human Skeleton: a medico-legal 
study. Mass. Med. Soc. prize essay for 1878. Boston, 1878. 
> Phila. Med. Times, Jan. 16, 1875 ; also Am. Journ. Med. Sei., 
Jan. 1879, 102. IDENTIFICATION OF BONES. 
103 
angle of 30° with the horizon nearly. According to 
Dwight (loc. cit.) the only objection to this rule is the 
exceptional fact that some subjects possess more than 
the normal number of vertebrae. 
The point of the coccyx is usually a trifle above the 
lower border of the symphysis pubis. 
In the female the centre of the body is at the sym- 
physis pubis; though in women above the average 
height the centre is slightly above this point, and in 
those below the average slightly below it. In the 
male the centre is in average examples a little below 
the symphysis, but it is subject to some variations, as 
in the female. 
In readjusting the dry or macerated bones of the 
limbs with the view of ascertaining the height of the 
individual, one-quarter of an inch must be allowed for 
the cartilages of the knee; one-eighth of an inch for 
the cartilages of encrustment of the astragalus and 
calcaneum; one-half of an inch for the remaining 
portions of the foot; and one-eighth of an inch for the 
joint between the occipital condyles and the atlas. 
For further information on the above and allied 
topics the reader is referred to Dr. Dwight's valuable 
essay, previously quoted, from which the writer has 
freely copied and epitomized. 
With reference to the question wrhethcr the bones 
are diseased, the same difficulties obtain as in study- 
ing the healthy bones. The lines of former fracture 
may be confounded with variation of the normal 
structure. The normal details of healthy nutrition 
may so resemble the products of inflammatory pro- 
cesses as not to be with certainty distinguished; while 
defects of development may be confounded with post- 
natal atrophic changes. 
Nevertheless careful comparisons will greatly assist 
in determining these and other distinctions. In the 
specimen suspected of having sustained fracture the 
part should be carefully macerated, since some in- 
stances of alleged atrophic or diseased change (as for 
example in the neck of the femur) have been shown by 
this means to be old ununited fracture. Lines of exos- 
tosis or inflammatory outgrowth can be distinguished 
from the lines of union of fracture by making a section 
of the bone. If at any time the bone has been fractured 
the evidence of the old lesion will be seen in the inte- 
rior as well as upon the surface; while, if it has never 
been so injured, the evidences of change are apt to be 
superficial, and even if deeply seated show increased 
thickness and density of the bone-tissue. 
Exposed surfaces of healthy adult bone, more par- 
ticularly those of the long bones, exhibit innumerable 
minute linear depressions which serve to maintain the 
periosteum in position. These are sometimes sup- 
planted in bones of muscular individuals by sparsely 
distributed elliptical nodules (see p. 101). In chronic 
peripheral inflammation these linear depressions are 
exaggerated in depth, and the spaces between them 
are apt to form minute, irregular eminences. In ex- 
treme examples of the results of formative inflamma- 
tory change such eminences may be confounded with 
the hyperostosed condition following chronic peri- 
ostitis. In bones showing the least sign of atro- 
phic change the condition opposite to the above is 
seen to exist. The linear depressions disappear, and 
the bone is everywhere smooth. Occurring at incon- 
stant and variable intervals are minute openings 
which can be distinguished from the orifices of vascu- 
lar canals by their being neither oblique nor crater- 
shaped, but having sharp-cut edges on the level of the 
bone surfaces as though punched out with a cutting 
instrument. 
A knowledge of the development of bone is essential 
to a correct understanding of some morbid processes. 
Thus the manner in which a bone will be affected bv 
disease is oftentimes the same as that in which it wras 
developed. The relations between the epiphysis and 
the shaft of a long bone will have to be remembered by 
the surgeon. The epiphysis may separate spontane- 
ously in some diseases and injuries. In fracture of the 
neck of the femur, that portion of the neck attached to 
the epiphysis may become absorbed, thus restoring to 
the epiphysis its original contour. In chronic arthritis, 
a series of characteristic appearances are restricted to a 
line near to or lying within the epiphysis. A seques- 
trum may be commonly restricted to a shaft, or, rarely, 
to an epiphysis.1 Disease of an epiphysis can affect the 
adjacent shaft as on the other hand disease of a shaft 
can affect the adjacent epiphysis. Many diseases of 
the joints have their origin in contiguous epiphyses. 
The restriction of morbid processes to portions of 
bone which are distinct from the point of view of 
development, is well' illustrated in the superior max- 
illa (q. v.)? 
In the composition of the complex association of 
bones, such as those of the skull or sacrum, certain 
surfaces are found remaining free from contact with 
one another. These ordinarily afford transit to im- 
portant nerves and vessels. In the instance of the 
1 Brodie, Surg. Lectures, 222, and Adams, Trans. Path. Soc. 
Lond., iii. 165, and Birnett, Ibid. vi. 288. Cat. to Mus. Guy's Hosp. 
No. 1484, 49. 
2 See also a paper by the author on Localization of Diseased Ac- 
tion in the Osseous System, Am. Journ. Med. Sci., July, 1870, 404. 104 
THE BONES. 
thyroid or obturator foramen in the innominate bone, 
the opening is closed by membrane, which, however, 
is pierced for the passage of a small nerve and artery. 
The development of the more complex single cranial 
bones, such as the temporal and sphenoid, explains 
the apparent anomaly of nerves and bloodvessels 
piercing resistant bony walls. Each vessel and nerve 
will be found to lie between the several elements 
composing the bone, or in a foramen or canal near 
the margin of the several component parts. Thus 
the facial nerve, in its intricate passage through the 
temporal bone, passes between the parts making up the 
embryonic temporal bone. The branches of the fifth 
cranial nerve pass through the margin of bones near 
the primary interspace between distinct embryonic 
portions of the sphenoid bone. In young subjects the 
foramina isolating the different branches of a nerve are 
imperfect, and in some animals they have no separate 
existence. It is rare for a nerve to pierce a bone, as a 
small branch is sometimes seen perforating the clavicle, 
or a nerve and artery passing through a foramen above 
the epitrochlear process of the humerus. 
kinds-those in which the lateral portions of the bone are 
larger than usual, and those in which the median portion of 
the bone is smaller than usual. The former is explained by 
the fact that increased functional activity has led to increased 
vascular supply ; and the latter by the fact that the retarded 
activity has led to diminished vascular supply. 
The direction by which arteries enter the long bones will 
be seen to determine the degree of vascularity at the ends 
thereof. Thus the nutrient vessel of the shaft of the femur 
being directed upward, congestion of the medulla is more 
apt to occur at the proximal than at the distal part of the 
bone. The nutrient vessel of the tibia, running as it does 
downward, will tend to fix the position of congestive change 
at the distal end of the bone. After fracture of a long bone, 
the portion remote from the main source of blood-supply may 
undergo atrophy-Epiphyses are very vascular, as compared 
to the shafts of bones, and, all things being equal, the longer 
the period of separation of an epiphysis from its shaft during 
development the longer is the vascularity of the epiphysis 
sustained, and therefore the greater the liability it incurs to 
the invasion of disease. 
(2) The lines of tendinous insertion of muscles of the 
limbs often modify the surfaces upon which they appear, 
and serve as boundaries of topographical divisions of the 
bones. This is conspicuous in the humerus, ulna, femur, 
tibia, and fibula. In the last two bones, the lines fix- 
ing the interosseous membrane-itself an intermuscular 
septum-separate the anterior from the posterior surfaces. 
The linea aspera of the femur is exclusively a ridge of mus- 
cular significance, and is determined by the fibres of the 
tendons of the adductor and extensor muscles here aggre- 
gated The lines of exaggerations of grow'th seen in bones 
are apt to be associated with the relations of the fleshy 
parts. They oftentimes constitute the minor degrees of 
difference between bones of individuals, and even between 
the corresponding bones on the opposite sides of the same 
individual. They give, in addition, the best clue to causes 
for location of morbid growths, particularly the exostoses. 
The exostoses often existing in the line of the condylar inser- 
tion of the Adductor Magnus muscle (the "rider's bone"), as 
well as the osteophyses along the lines of intermuscular septa 
at the lower part of the fibula, are of this significance. 
In muscular subjects the humerus is often obscurely 
angulated at the part at which the Deltoid muscle is at- 
tached. This is sometimes so pronounced as to form a 
variety in the shape of the bone. In other bones the 
surface of origin for the third head of the Triceps muscle 
is convex instead of flat, and gives the bone the appearance 
of being bowed forwards. If such a specimen be laid 
upon a plane surface, the distal end of the bone will not 
touch the plane-the bone resting upon the head and the 
centre of the above-named tricipital surface Specimens of 
chronic ostitis of the humerus are not rare in which the dis- 
ease has been confined to this portion of the humerus On 
the other hand, an osseous surface is sometimes seen covered 
REMARKS. 
Bones as Mechanical Agents The student is espe- 
cially urged to examine the bones as mechanical agents. lie 
should constantly seek for the conditions which underlie or 
(not to speak too boldly) create the ossific forms. Thus, in 
studying the bones of the face, he should observe that the 
ascending nasal process of the superior maxilla is stout in 
order that it should receive and distribute the force of the 
occlusion of the lower maxilla against the upper; while 
the lachrymal bone immediately behind it is thin and weak, 
since none of the same or similar labor is exacted of it. 
Likewise, in the innominate bone the prismatic elevation 
extending from the sacro-iliac symphysis to the acetabulum 
comprises the most massive portion of the bone, since it is 
the supporter of the sacrum and indirectly of the superim- 
posed vertebrae; while the bone on either side of the thick- 
ening (often so thin as to be translucent) possesses little or 
no strength. 
Variations in the Shapes of Bones-Variations in 
the form of bones are due to alteration of (1) blood-supply, 
and (2) the strength of muscular attachments. 
(1) In studying the varieties of form due to blood supply, 
it must be remembered that the needs of the tissues determine 
the quantity of blood going to them. Hence, variations with 
a tendency to excess of size are found in locations showing 
the greatest functional activity, while variations of reduction 
of size are seen in locations of diminished activity. For 
instance, the variations in the form of the atlas are of two REMARKS 
105 
by a broad smooth muscle, and is in this way protected from 
the tendency to excessive growth elsewhere evident. The 
impression of the Temporal muscle is rarely the seat of dis- 
eased action of any kind. In some remarkable examples on 
record of diffused cranio-facial exostosis the temporal regions 
are entirely free from disease.1 
Many processes of bone are created, as it were, by mus- 
cular traction. Thus the pterygoid process of the sphenoid 
bone has no existence in animals, whose muscles for moving 
the lower jaw are disposed in a manner different from those 
of man and mammals. The massive mastoid process is 
absent when the Sterno-Cleido-Mastoid muscle is also absent, 
as in most quadrupeds. The femur of some animals, such 
as the rhinoceros, possesses three trochanters. Two of these 
correspond with those found in man. The third is for the 
insertion of muscular slips not found in man, except as anom- 
alies. It can be said, indeed, that the trochanters in the 
human femur are correlative with the muscles inserted into 
them. In the absence of the muscles the processes would 
never have appeared. 
The effect of muscular action in modifying the shapes of 
bones has formed the subject of special study by Prof. Henry 
J. Bigelow.2 According to this writer, the inter-trochanteric 
ridge of the femur is simply a buttress erected for the inser- 
tion of muscles upon and over the true neck, which is repre- 
sented by a more deeply-seated septum or layer of compact 
tissue (see Femur). Dr. Thomas Dwight3 detects similar 
superficial deposits of bone beneath the anterior inter-tro- 
chanteric ridge, and sometimes under the coronoid process of 
the ulna and the tubercle of the radius. 
Muscular Action as a Cause of Ostitis and Ne- 
crosis Diseased processes may be excited through mus- 
cular action. Necrosis has been known to follow ostitis, the 
result of prolonged traction of a muscle upon the bone yield- 
ing its points of insertion. Prof. Syme,4 in commenting 
upon a case of sinus of the hip depending upon exfoliation 
from the pelvis, states that the patient had first experienced 
uneasiness after a day's employment in curing herrings, 
and that the discharge of his duty had required him to 
stand with his feet apart, alternately stooping and stretch- 
ing his arms upwards to the full extent; subsequently to 
which he had felt a painful sense of fatigue in the back part 
ot the thighs. It then occurred to the author that the 
disease had originated from over-exertion of the muscles 
which arise from the tuberosity of the ischium, and that 
the bone with which they are there connected had suffered 
in consequence so as to exfoliate instead of being excited to 
preternatural growth, as Sir Astley Cooper witli apparent 
good reason thought likely to happen from inordinate mus- 
cular contraction. It seemed evident enough that injuries 
similar to the foregoing cannot result from the direct effect of 
violence, since in all the cases detailed the bone concerned 
was securely protected by its situation from any such injury. 
In all of them there was violent muscular contraction, and it 
seems probable that this may have been the exciting cause 
of inflammation and death of the bone. 
The Shapes of Bones as Modified by Diseased Ac- 
tion-Bones serve as resistant masses to the superincum- 
bent weight of the body. In rickets and other diseases which 
tend to soften the bones, characteristic deformities are found 
to result from the bones yielding to the weight of the tissues. 
The base of the skull may become flattened from the 
weight of the brain, and the bones of the vertex distended 
and distorted from pressure from within. The bones of the 
lower extremities from analogous causes become bent. In 
the long bones which have undergone softening, but which 
have regained their former toughness and rigidity, strong 
ridges are observed upon the concave aspects of the curve ; 
and this superabundant bone, according to Stanley,1 is 
placed exactly where the curvature of the bones renders 
them mechanically weaker, and where, consequently, their 
greatest waste of tissue occurs. This compensative arrange- 
ment is called by Stanley reparative hypertrophy. 
Bone may also be altered in form by pressure which has 
been long maintained against it. An aneurism in an artery 
lying upon a bony surface will cause the absorption of the 
bone at the place of greatest pressure. Thus aneurism of 
the ascending aorta will create absorption of the sternum or 
ribs; and aneurism of the descending aorta, of the bodies of 
the vertebrae. Tumors of other kinds will in the same way 
cause bone to yield; tumors of the tongue will create de- 
formation of the jaws, and tumors in the nose and pharynx 
will press upon and destroy the bones of the nasal region. 
One of the most remarkable instances of this pressure 
seen in the latter locality is reported by Hilton,2 in which an 
osseous tumor of the left side of the face had distended the 
superior maxilla and adjacent structures to a remarkable 
extent. The mass subsequently underwent spontaneous 
evulsion, but the deformity created by its former presence 
persisted, in addition to which a cavity communicating with 
the enlarged nostril remained-An hydatid tumor placed 
between the left lung and the diaphragm has been known to 
cause absorption of the bodies of the vertebras and to permit 
intrusion of the hydatids into the vertebral canal. This in- 
trusion occurring suddenly gave rise to the impression that 
hemorrhage had occurred in the spinal cord-Even the 
petrous portions of the temporal bone will not long resist 
contact with a tumor much less compact than itself. Dr. 
Morris Longstreth,3 in dissecting the relations of a sarcoma 
1 H. Lebert. Traite d'Anat. Pathol. 1857. Atlas, pl. xxxii. 
Murchison, Trans. Path. Soc. London, xvii. 243, pl. 10. 
2 The Hip, 1869, 125. 
3 Journ. Anat, and Phys., 1875, 311. 
4 Ed. Med. and Surg. Journ., 1828, contains Syme's original 
notice of this subject. 
1 Illustrations of the Effects of Disease and Injury of the Bones. 
London, 1849, pl. xx. p. 22. 
2 Guy's Hosp. Rep., i., 1836, 493. 
3 Burnett's Treatise on the Ear, 555. THE BONES. 
106 
which had originated in the left cerebellar hemisphere, and 
had sent a portion of its mass within the internal auditory 
meatus, noticed that the bony canal was much widened 
and funnel-shaped. In a case reported by Boettcher1 the 
tumor had dilated the canal in all directions. 
Interstitial absorption from undue pressure plays an im- 
portant part in the causation of deformity of the spine, in 
which condition bodies of the vertebrae become changed in 
outline-sometimes to a remarkable extent-not from any 
primary diseased action therein, but from long-continued 
vicious pressure. The question of prognosis in all cases of 
spinal deformity must be wisely based upon what is known 
of the deformed shapes of the vertebrae entirely apart from 
the question of removal of the original exciting cause. 
Bones, in addition to the modifications of their surfaces 
due to the origin and insertion of muscles, may be changed 
in form at certain localities by tendons and bloodvessels. 
The tendon of the Obturator Interims, as it lies over the in- 
nominate bone above the tuberosity of the ischium (creating 
grooves even in the normal bone), will cause deeper and 
broader grooves to appear in bones which are preternaturally 
softened. In a skeleton of a giant, preserved in the Mutter 
Museum in Philadelphia, the exaggeration in these grooves 
is well represented. 
In like manner the points of origin and insertion of 
muscles will cause in young bones, or in those of the charac- 
ter above described, the opposite effect, and will create 
shallow depressions upon the surface of the bone instead of 
prominences. 
gence of the lateral portions is triangular, and presents 
one posterior and two lateral subrounded angles.- 
The vertebral canal accommodates the spinal cord and 
membranes ; the spinal nerves, as they pass from their 
apparent origin in the spinal cord to their points of 
exit from the vertebral canal; the vertebral artery on 
its way from the vertebral foramen of the atlas to enter 
the foramen magnum; and the lymph-space between 
the membranes.1 
The cancelli.-The lines of cancelli in the ver- 
tebrae are arranged in three series. The first consists 
of longitudinal concave lines with their concavities 
directed forward. The second resembles the fore- 
going, but the concavities are directed backward. 
The third series are transverse,-the upper lines 
being concentric to the superior, and the lower to 
the inferior articular surface. 
The other general features of a vertebra are the 
following:- 
The pedicle, which is that rounded part of the lateral 
portion lying between the body and the lateral angle; 
the lamina, the thin, flattened part lying between the 
lateral angle and the spine,-it is seen to be vertically 
compressed at its base; the superior oblique or articular 
process lying at the base of the pedicle,-it presents 
an articular facet looking backward ; the inferior ob- 
lique or articular process lying upon the base of the 
lamina at the angle,-it presents an articular facet 
looking forward; the inferior notch lying beneath the 
pedicle, and between the body of the vertebra and 
the ,lamina; and the smaller superior notch-a less 
constant feature-lying upon the pedicle between the 
body and the superior articular process.-In articula- 
tion the apposition of a pair of superior and inferior 
notches constitutes an intervertebral foramen for the 
exit of a spinal nerve. 
THE VERTEBRAL COLUMN. 
The vertebral column is the figure resultant upon 
the apposition of the vertebrae in natural order. It 
is usually accepted to include the sacrum and coccyx. 
But for practical purposes nothing is gained by thus 
THE VERTEBRAE. 
General Considerations. 
Every vertebra, excepting the atlas, is composed 
essentially of three parts, viz., a body, and two lateral 
portions.2 The body defines the vertebral canal in 
front, and the lateral portions at the sides and behind. 
Each lateral portion arises from the posterior outer 
margin of the body, and passes for a short distance 
outward and backward. It is thence abruptly de- 
flected inward and backward, and joins its fellow of 
the opposite side to form at the point of contact the 
spinous process or spine. The union of the lateral 
portions constitutes the vertebral arch. The figure of 
the vertebral foramen thus determined by the conver- 
1 The vertebral canal varies greatly at different parts of the 
column. According to Humphry, the antero-posterior diameter, 
within the axis, is but | of an inch; from this it gradually dimin- 
ishes to | of an inch at the middle of the dorsal region. Opposite 
the last lumbar vertebra it increases to % of an inch, and thence 
rapidly diminishes until the sacrum is reached. The frontal 
diameter at the atlas measures 1| inch, at the axis 1 inch, at the 
second dorsal vertebra f of an inch, at the last j of an inch, and 
at the lumbar vertebrae 1 inch. 
1 Archiv Oph. and OtoL, iii. 134. 
2 The atlas, while defining the vertebral canal in common with 
the other vertebrae, is composed of two lateral portions only, and 
is technically without a body. THE VERTEBRAE 
107 
uniting these parts, since special descriptions and en- 
tirely distinctive relations are required properly to 
elucidate them. Omitting, therefore, the sacrum and 
coccyx, the vertebral column is composed of- 
7 cervical vertebras, 
12 dorsal vertebras, 
5 lumbar vertebras, 
making a total of 24 bones. 
The vertebral column is best studied when the in- 
tervertebral disks, ligaments, and articulations are in 
position. By this union of the separate bones, the 
intervertebral notches become connected into inter- 
vertebral foramina; the various segments of the 
vertebral canal join with one another; the facets for 
articulation of the ribs become complete sockets ; and 
the space in each bone between the spinous and the 
transverse processes extending the entire length of 
the spine,1 becomes known as the vertebral groove. 
As a whole, the vertebral column protects the con- 
tents of the vertebral canal, affords attachments to 
important muscles, and supports the head, while 
guarding it from shock. It serves in front to protect 
the viscera, and in an indirect manner to furnish 
points of attachment to structures holding the viscera 
in position. Thus the descending aorta is firmly fixed 
to the spine along its entire course,-and from and 
about it the mesenteric and other peritoneal folds 
arise. 
The vertebral column increases in size from above 
downward, and may be said to rest upon the sacrum 
by the massive bodies of the lumbar vertebrae. Its 
form, therefore, is pyramidal, but this form is much 
modified by the presence or absence of ribs as well 
as by surfaces for ligamentous and muscular attach- 
ments. Its length is about one-third that of the body. 
Mechanics of the Vertebral Column.-The 
mechanics of the vertebral column embraces three 
distinct subjects:- 
(1) The adaptation of the vertebrae to support the 
head. 
(2) The degree of motion present between the ver- 
tebrae. 
(3) The production of spinal curvatures. 
(1) The adaptation of the vertebrae to support the head. 
-The head rests directly upon the lateral portions of 
the atlas. The weight is thence conveyed through 
the superior articular processes to the bodies of the 
vertebral column, but a portion is sent to the lateral 
masses of the remaining cervical vertebrae as well, and 
through them to the bodies of the dorsal and lumbar 
vertebrae. There are thus two lines of weight in the 
vertebral column: one direct through the superior ar- 
ticular facets of the axis to the bodies; and another 
passing from the same point downward through the 
columniform articular region of the cervical vertebrae 
to the dorsal region, whence it again passes to the 
bodies, which now sustain the weight of the super- 
incumbent mass. 
The shape of the spine directly assists in sustaining 
the weight of the head. According to F. O. Ward,1 
the lumbar region-the most massive-contributes 
seven parts to the column; the dorsal, eleven; and 
the cervical, five. The lumbar and nine lower dorsal 
vertebrae form a pyramid whose base rests on the 
sacrum. The six lower cervical vertebrae form another 
pyramid, whose base rests on the first dorsal, and whose 
apex is surmounted by the atlas on which again is 
balanced the globe of the cranium. Between these 
two pyramids, and extending from the base of the 
upper to the apex of the lower, intervene the three 
superior dorsal vertebrae, which constitute a third, 
but inverted pyramid. Thus, though the whole col- 
umn presents a cone whose base is somewhat more 
than double the diameter of the apex, yet this main 
pyramid is composed of three subordinate pyramids. 
It is evident from this disposition of parts that a 
structure of enormous strength arises well adapted to 
the special demands made upon it. 
(2) The degree of motion present between the vertebrae. 
-The articular processes are also of great import- 
ance in the mechanics of the vertebral column. The 
motion between the articular surfaces is greater in the 
cervical than in either the dorsal or the lumbar re- 
gion. On the whole it may be said to become less in 
regular degree from above downward. In the lum- 
bar region the inferior articular processes are in a 
measure embraced by the superior. In the dorsal 
region the surfaces are simply apposed, but the mo- 
tion between them is impaired by the imbrication of 
the dorsal spines and the manner of articulation of 
the ribs. 
(3) The production of spinal curvatures.-The weight 
of the body above, and the traction of muscles 
at the sides, cause the vertebral column to assume 
a number of curvatures. These modify the shapes 
of the bones, and enable them to best accommo- 
date themselves to the forces mentioned. The pecu- 
liarities of shape of the bodies, the intervertebral 
1 It will be noticed that the words " spine" and " vertebral col- 
umn" are used synonymously, as are the words "spine" and 
"spinous process." 
1 Outlines of Human Osteology, 18. 108 
THE BONES 
disks, the articular processes, etc., arc all moulded 
to one another, as a series of effects, by the kinds of 
pressure and traction to which they have been and 
arc subjected. To such an extent, indeed, is this the 
case that the curvatures remain after the spine has 
been detached from its surroundings. 
The antero-posterior curvatures.-The main curva- 
tures are antero-posterior, and are three in number 
-the cervical, the dorsal, and the lumbar. The first 
presents a convexity forward ; the second, backward ; 
and the third, forward. The figure of the spine is 
thus sinuous. 
Humphry1 has accurately defined the curves of the 
spine to be as follows: The first or cervical curve be- 
gins at the top of the odontoid process, and terminates 
at the middle of the second dorsal vertebra. It has its 
convexity in front, and forms 18° of a circle whose 
radius measures 6f inches; the most prominent point 
anteriorly is the forepart of the body of the fourth 
cervical vertebra.-The second or thoracic curve be- 
gins at the middle of the second, and terminates at 
the middle of the last dorsal vertebra. It has its 
concavity forwards, and forms 42° of a circle, whose 
radius measures 12f inches; the most prominent 
point posteriorly is the hinder edge of the body of 
the seventh or eighth vertebra.-The third or lum- 
bar curve, beginning at the middle of the last dorsal, 
terminates at the lower and anterior edge of the last 
lumbar vertebra. It is convex anteriorly, and forms 
80° of a circle, whose radius is 5f inches.-The fourth 
or pelvic curve, sharper than either of the others, 
begins at the upper edge of the sacrum, and termi- 
nates at the top of the coccyx. It forms 125° of a 
circle, whose radius is 2f inches. The degree of cur- 
vature is not uniform, but is greatest a little below the 
middle. 
The relation of weiyht to curvatures. - A direct 
line from the superincumbent weight at the head 
passes through the odontoid process and points of 
confluence of spinal curves, and falls a little in 
front of the promontory of the sacrum. This line 
passes through the points at which the vertebral 
curves run into and support each other. Lying in 
advance of the bodies of the fifth to the ninth dorsal 
vertebras inclusive, it leaves a larger portion of the 
dorsal curve behind the line of gravitation than is the 
case in the cervical and lumbar regions. In the 
stooping position the line falls further in front of the 
one above indicated. 
The curves are most pronounced in persons who 
have the greatest degree of normal exercise of the 
body, as in savages, and in those whose occupations 
accustom them to carry weights on the head. On 
the other hand, they are defective in persons of a 
sedentary habit and in bed-ridden invalids. 
The curves are liable to change when the position 
of the weight is shifted. In forced stooping the lum- 
bar curve is obliterated and actually slightly reversed. 
In the sitting position the hollow of the spine at the 
lumbar region disappears. 
Lateral curvatures.-The existence of normal lateral 
curvatures in the spine has been a subject of some 
difference of opinion among anatomists. Dods, in 
1824, appears to have been the first clinical writer 
accurately to define the condition. Quain, Humphry, 
and Ward among systematic writers describe a slight 
degree of lateral curvature as observable in most 
cases in the dorsal region. Its convexity is directed 
to the right-a result due presumably to the greater 
use made of the right than of the left arm. According 
to Beclard, a curvature is exhibited to the opposite 
side in left-handed persons. This statement is dis- 
puted by Adams,1 who doubts the existence of lateral 
curvature as a physiological condition. 
That such a curvature, however it maybe classified, 
is dependent upon muscular action has been generally 
maintained by observers, who are inclined to accept 
the kind of explanation presented by Quain as appli- 
cable to all examples. Lateral curvature is never 
seen, according to Sayre,2 in vigorous subjects who 
are habituated to carrying weights on the head; 
since both right and left groups of the muscles of the 
spine are here equally exerted. If a lateral curvature 
is developed in the dorsal region, which is commonly 
the case, a secondary compensatory curve in the 
opposite direction is developed in the loin. 
Lateral curvature may also follow upon the insuf- 
ficient support given the entire trunk by inequality 
in the lengths of the lower limbs. In cases where one 
limb is much shorter than the other, as in fracture of 
one of the bones of the lower extremity followed by 
much shortening (or in paralysis or insufficient de- 
velopment), the side of the pelvis answering to the 
shortened limb falls, and a compensatory lateral 
deviation of the spine from the normal line always 
ensues. 
Lateral curvature with rotation. - Humphry3 no- 
ticed, as early as 1850, that in lateral curvature the 
motion is not simply of a lateral character, nor 
1 See p. 109. 
2 Spinal Disease and Curvature, 92. 
3 L. c., 171. 
1 The Human Skeleton, 147. THE VERTEBRA. 
109 
one strictly confined to the sides of the bodies, but 
that the hinder parts of the sides, or the points of 
confluence of the arches and bodies, are involved, 
viz., at the points at which the vertebrae remain 
cartilaginous after the rest of the bodies and arches 
have become ossified. It is certainly suggestive 
that these curvatures are common in young grow- 
ing persons. In consequence of the above-named 
parts yielding, the bodies become twisted or rotated 
a little to the opposite side. This writer calls the 
motion thus described the vertebral twist, and states 
that it is an almost constant accompaniment of lateral 
curvature. A. B. Judson1 has also arrived at the 
conclusion that a rotatory motion of the bodies of the 
vertebrae is present in lateral curvature, and, indeed, 
initiates the movement. His theorem, which is stated 
independently of Humphry's, and varies therefrom, 
is based upon the fact that the posterior portion of 
the vertebral column, being a part of the relatively 
fixed dorsal parietes of the chest and abdomen, is 
confined to the median line of the trunk; while the 
anterior portion, projecting as it does into the thoracic 
and abdominal chambers, and being devoid of lateral 
attachments, is at liberty to move to the right and 
left of the median line. By means of an appropriate 
apparatus, this observer induces lateral curvature with 
rotation of the vertebras by vertical pressure received 
upon the summit of a vertebral column whose base 
is fixed. Double curvature with rotation in each 
curve may be produced by confining one of the dorsal 
vertebrae at the same time that pressure is exerted 
from above. These experiments appear to have 
been made on an artificial preparation of the spine, 
without ligaments. They need repetition on a trunk 
with ligaments, muscles, ribs, diaphragm, and liver 
in place before the results can be accepted.-The 
rotatory motion is freer at the upper part of the 
dorsal region than elsewhere, being slight in the 
neck, and absent in the loin and its transition to the 
dorsal region. 
According to W. Adams,2 " The articular processes 
undergo very important structural changes at an 
early period of the formation of lateral curvature. 
The articular facets become altered in their direction 
and aspects, according to the extent of the lateral 
deviations of the bodies of the vertebrae-thus in- 
creasing in degree of alteration in proportion to the 
severity of the case. In the lumbar region where 
these articular processes are naturally nearly vertical 
in direction-looking inwards and outwards respect- 
ively-they gradually assume in a severe case of 
lateral curvature a very oblique direction. In 
lateral curvature with rotation, the transverse pro- 
cesses are depressed towards the abdominal cavity, 
and, in severe cases, cannot be felt by external exam- 
ination ; whilst those on the convexity of the curve 
project backwards towards the skin, and may even 
rise to the level of the apices of the spinous pro- 
cesses, and be readily felt along the outer margin of 
spinal muscles, which they also protrude backward 
and are rendered prominent. This deviation in the 
direction of the transverse processes is extremely 
important in a diagnostic point of view, and will 
enable the observer to diagnose a curvature in the 
lumbar region in cases in which no lateral deviation 
of the spinous processes exists." 
The intervertebral foramina.-The interver- 
tebral foramina vary in different regions. They are 
more forward in the neck, where they are small and 
round, than in the loins. 
The spines.--The spines are arranged in accord- 
ance with their degrees of motility. They are directed 
either horizontally backward or slightly downward in 
the neck and loins-but downward and backward in 
the dorsal region, where they overlap. In the neck 
they are distinct and wride apart, and permit the liga- 
menta sub-flava to be seen from without. In the 
region of the back they overlap. In the loin, while 
not overlapping they nearly touch one another, and 
protect the vertebral canal and contents. 
Homologies.-Study of the development of the 
vertebrae has proved that the transverse processes of 
different vertebrae are not of the same homological 
value. 
The anterior tubercle of the transverse process of 
a cervical vertebra represents, it is thought, a rudi- 
ment of a rib, since it answers in position to the rib of 
a dorsal vertebra, and arises from a distinct centre 
of ossification. In like manner the transverse process 
of a lumbar vertebra may be held to be homologous 
to a rib. The transverse process of a dorsal vertebra 
is homologous to the posterior tubercle of a cervical 
vertebra, as well as to the accessory process of a 
lumbar. Reference to this arrangement furnishes the 
true explanation of the anomaly of the anterior tu- 
bercle of one of the lower cervical vertebrae being 
found as a true rib-like quantity. 
1 Trans. N. Y. Acad, of Med., 1876, 315. Literature. 
2 W. Adams, Med. Times and Gazette, Dec. 7, 1861, 574. 110 
THE BONES. 
Transition vertebra?.-While the characters of 
the cervical, dorsal, and lumbar are quite distinctive, 
the upper dorsal resemble the cervical, and the lower 
the lumbar. Thus the first and second dorsal verte- 
brae have bodies recalling those of the cervical; in the 
tenth to the twelfth dorsal vertebrae, the rudiments of 
the accessory and mammary processes are present; 
and the floating rib suggests a lumbar transverse pro- 
cess which is merely unfixed. 
DEVELOPMENT. 
Each vertebra arises from three main centres of 
ossification,-one for the body of the bone, and one 
for each of the two lateral portions, including the 
laminae. The centres for the latter appear about the 
seventh week, and the centre for the body about the 
eighth week. These parts are separate at birth. 
In addition to the above an epiphyseal centre arises 
within the spinous process and the transverse pro- 
cesses of the vertebrae about the sixteenth year. In 
the lumbar vertebrae both of the mammillary processes 
receive a similar centre. The body is furnished with 
two accessory centres-one on either side-at about 
the twenty-first year. 
The development of the atlas and axis differs from 
the foregoing.-The atlas is without a distinct cen- 
tre for the body. The two centres of ossification 
within the laminae extend across the cartilaginous 
anterior arches, one or two inconstant centres appear- 
ing therein at about the first year.-The axis arises 
from a centre for each lateral mass; one for the body, 
which appears at the sixth month; and two for the 
odontoid process, which appear at about the same 
time. These are united to the body near the third 
year. An additional accessory centre is seen occu- 
pying the odontoid process. 
The development of the anterior tubercle of the 
cervical transverse processes may differ from that of 
the other vertebrae by reason of the morphological 
relation existing between this tubercle and one of the 
series of ribs. The tendency of the tubercle to have 
a distinct development from the remainder of the 
transverse process increases as the dorsal vertebrae 
are approached. The seventh cervical usually pos- 
sesses a distinct centre in this process. Failure of 
union between this centre and the rest of the bone 
gives origin to the so-called cervical rib (see p. 000). 
The transverse processes of the lumbar vertebrae 
may remain distinct from the body of the bone in the 
manner just indicated. 
Embryology demonstrates that the vertebral column 
arises from two distinct portions of the dorsal layer 
of the embryo. The bodies of the vertebrae arise from 
beneath the medullary groove in and about the ele- 
ments of the chorda dorsalis, called the protovertebrae. 
The elements of the future lamina? lie within the 
medullary folds at the side of the groove. It is plain 
that the method of growth of the body is different 
from that of the lamina?, and that the errors of devel- 
opment witnessed in the latter will be the result of the 
imperfect approximation between the right and the 
left sets. The laminae most frequently failing to unite 
with one another are at that portion of the column 
which attains perfection last, namely, the lower por- 
tion of the lumbar series. This defect of union is 
known under the name of spina bifida. 
THE CERVICAL VERTEBRAL 
The cervical vertebras are the vertebrae of the neck. 
The body of each cervical vertebra (fig. 1, Plate XIII.), 
excepting that of the atlas and axis, is broader 
from side to side than from before backwards, and is 
slightly inclined downward and forward. The upper 
surface is concave from side to side, and possesses an 
elevated lateral border. The lower surface is slightly 
concave from before backward, and yields a pro- 
nounced anterior border (fig. 1, Plate XV.). Its 
lateral edges appear to a trifling extent upon the 
sides of the body as shallow depressions. 
Each lamina (Fig. 67) springs from the body at 
about its middle. The pedicle is rounded, and is di- 
1. Tho body. 2. The vertebral canal, formed at the aides by the lamin®. 
3. The pedicle. 4. The lamin®, converging to form the bifid spine. 5. The 
transverse process. 6. The vertebral foramen. 7. The superior articular pro- 
cess. 8. The inferior articular process. The superior notch is indicated as the 
space between the body and the superior articular process. 
rected outward until it reaches the mass between the 
articular processes. Beyond the articular processes 
the lamina becomes thin and compressed, inclines 
backward, joining the lamina of the opposite side to 
form the bifid spine, and to give shape to the some- 
what triangular vertebral canal. Lying above the THE CERVICAL VERTEBRAL 
111 
pedicle, and between the lateral border of the body 
and the superior articular process, is the superior 
notch. Lying below the pedicle, and between the 
outer side of the body and the inferior articular pro- 
cess, is the inferior notch. 
The articular processes are inclined parallel to one 
another downward and backward. The superior 
articular process looks upward and backward; the 
inferior looks downward and forward. The portion 
of bone intervening between the articular processes 
is massive and columniform. 
The transverse process arises by two roots-a pos- 
terior or larger arising from the pedicle, and an ante- 
rior or smaller arising from the body. The process 
looks directly downward, and is pierced at its base 
by the vertebral foramen for the transmission of the 
vertebral artery. The process is grooved above for 
the anterior branches of the cervical plexus (fig. 1, 
Plate XV.), and presents an anterior and posterior 
tubercle; the Scalenus Anticus muscle is attached to 
the former, and the Levator Anguli Scapulae muscle 
to the latter. The anterior tubercle, from its serving 
as a guide for tying the carotid artery, is called by 
Lisfranc the carotid tubercle. 
The first (atlas), the second (axis), and the seventh 
cervical vertebrae (vertebra prominens), having many 
peculiar features, demand separate descriptions. 
THE ATLAS. 
The atlas or first cervical vertebra (fig. 2, Plate 
XIII.) js without body or spinous process. It is 
further characterized by the greater size of the lateral 
masses, by the conspicuous transverse processes, by 
the intervertebral grooves being placed behind the 
superior articular surface, as well as by many negative 
features, fn place of the body, a short arch is seen 
which is known as the anterior surface or arch. This 
extends between the lateral masses in front, while join- 
ing them behind is the larger posterior surface or arch. 
The anterior arch arises from the entire anterior 
borders of the lateral masses. It is compressed from 
behind forward, and is furnished in front by a promi- 
nence known as the anterior tubercle for the attach- 
ment of the Longus Colli muscle. Behind it is seen a 
large facet for articulation with the odontoid process 
of the axis. 
The posterior arch arises from the middle of the 
posterior border of the lateral mass, where it is com- 
pressed from above downward, and grooved (sinus 
atlantis or intervertebral groove) for the vertebral 
artery. The hinder portion is more robust, and 
yields a minute tubercle for origin of the Rectus 
Capitis Posticus Minor muscle. 
The transverse process is directed slightly down- 
ward and outward, and presents a broad, scarcely 
bifid extremity. Its anterior root arises from the 
upper border of the lateral mass ; that portion behind 
the foramen arises from the middle of the lateral 
mass, and merges thence with the origin of the pos- 
terior arch. The under surface of the process is 
roughened. The transverse process, as in the other 
vertebras, excepting the seventh, transmits the verte- 
bral artery. Each lateral mass presents above and 
below an articular surface, and the two elements 
defining the vertebral foramen are more completely 
fused beyond the foramen than in the other vertebrae. 
The superior articular process is of an oblong shape, 
and is concave for articulation with the occipital con- 
dyle. Its anterior and lateral edges are thin, and 
nearly on a level with the anterior arch. The poste- 
rior border is thickened, and forms a projection above 
the groove for the vertebral artery and first cervical 
or suboccipital nerve. 
The lower articular process is more rounded than 
the upper. It is scarcely at all concave, and is di- 
rected obliquely upward and inward, and often slightly 
projects at the sides and in front. 
The inner border of the lateral mass is roughened, 
and lies within the vertebral canal. It presents a 
tubercle, lying directly above the inner border of 
the inferior articular surface, for attachment of the 
transverse ligament. 
The vertebral canal is relatively larger than in 
other vertebrae, and is remarkable for its contraction 
between the lateral masses for the accommodation of 
the odontoid process and the crucial and the check 
ligaments (fig. 2, Plate XXXVI.). The posterior half 
of the canal defined between the laminae is wider 
than deep, and receives the spinal cord and vertebral 
arteries and veins (fig. 3, Plate XXXVI.). 
Remarks.-The sinus atlantis may be converted 
by an osseous bar into a foramen.-A spicule of bone 
may spring from the posterior arch at the upper 
surface of the point of junction of the lamina and 
the pedicle, and pass over the position of the vertebral 
artery and the suboccipital nerve to the back part of 
the superior articular surface. A second spicule may 
pass from the upper surface of the transverse process 
to the outer edge of the superior articular surface, THE BONES. 
112 
crossing the place of exit of the anterior division of 
the first spinal nerve.1 
The atlas tends in its varieties to hypertrophy of 
its lateral and atrophy or defective development of 
its median parts. The former variety may have the 
anterior tubercle of exaggerated size, when the pro- 
minence felt in the neck behind the angle of the lower 
jaw would be larger than usual; a process of bone 
may arise from the upper surface, and may even join 
the rarely present para-mastoid of the occipital bone. 
Of the latter variety, the anterior arch may be imper- 
fectly ossified and a joint intervene, and the posterior 
arch be entirely absent, or a median hiatus of con- 
siderable size may exist which is occupied by fibrous 
tissue. 
In a very instructive case reported by Kussmaul 
and Tenner,2 an exact relation was detected between 
defective development of the atlas and the recurrence 
of epileptic convulsions. The patient was a boy 
twelve years of age, and the attacks supervened only 
upon rotation of the head. The coincidence of this 
motion with the attacks led to a careful examina- 
tion of the parts after death. The defect of devel- 
opment described in the preceding paragraph was 
found to exist. The right segment of the imperfect 
arch passed across the median line nearly to the 
opposite side of the bone, and overlapped the left 
segment by one-third of an inch. The head being 
strongly rotated upon the spine, the ends of the im- 
perfect posterior arch were seen to move forward, 
and in so doing the capacity of the vertebral canal 
was diminished and its contents compressed. It was 
inferred by the reporters that such action of the parts 
had followed each act of rotation during life, and, as 
a result of the spinal compression in this way induced, 
the convulsions had ensued. This conclusion appears 
to be a reasonable one, since it is in full harmony with 
the causation of at least one form of epilepsy as defined 
by writers on nervous disease, namely, that caused 
by pressure against the brain and spinal cord from 
exostoses, etc. 
It is seen from this case that a deformation, which 
is at first sight of purely theoretical significance may 
be of great importance as an exciting cause to dis- 
eased action. 
THE AXIS. 
The axis or second cervical vertebra (figs. 3 and 4, 
Plate XIII.) presents a body which is compressed 
from before backwards and furnished above with a 
conspicuous tooth-like process,-the odontoid process. 
The laminae of the axis are massive, but its trans- 
verse processes are small and possess but a single 
tubercle. As is the case with the atlas there is no 
superior notch, i. e., the superior facet is placed in 
front of the intervertebral groove. 
The body of the axis is marked in front by a ver- 
tical eminence, upon either side of which is a depres- 
sion for attachment of the Longus Colli muscle. 
The anterior border of the under surface is produced 
below the level of the posterior. 
The lower surface is moderately concave for recep- 
tion of the third cervical vertebra. 
The upper surface is furnished with the conspicuous 
odontoid process. This is a vertical cylindrical emi- 
nence, whose anterior surface is slightly inclined 
backward, but whose posterior surface is nearly ver- 
tical. Its lip is sometimes prolonged. The lateral 
surfaces of the process near the lip are depressed for 
attachment of the powerful check ligaments. The 
process is constricted at the base behind, and at the 
sides by a well-defined neck for the accommodation 
of the transverse ligament. The anterior surface pre- 
sents an oval facet for articulation with the atlas (fig. 
3, Plate XXXVI.). 
The laminae of the axis arise from nearly the entire 
side of the body ; directly behind the superior articu- 
lar process the upper border is faintly depressed to 
form the inter-vertebral groove for the passage of the 
second cervical nerve. The spinous process is mas- 
1 W. Allen, Journ. Anat, and Phys., xiv., 1879, 18. 
2 Moleschott's Untersucliungen zur Naturlehre der Menschen und 
der Thiere, 1857, iii. 122. 
EXPLANATION OF PLATE XIII. 
Fig. 1. A cervical vertebra, seen from in front. 
Fig. 2. The atlas, seen from above. 
Fig. 3. The axis, seen from the side. 
Fig. 4. The axis, seen from in front. 
Fig. 5. A dorsal vertebra, seen from in front. 
Fig. 6. A dorsal vertebra, seen from the side. 
Fig. 7. A lumbar vertebra, seen from in front. 
Fig. 8. A lumbar vertebra, seen from the side. PLATE XIII 
Fig. 2 
Fig. 3 
Fig 4 
Fig 5 
Fig 6 
Fig. 7 
Fig 8 
T. Sinclair & SonLitli. THE CERVICAL VERTEBRAE. 
113 
sivc and bifid, and beneaih is grooved its entire 
length. 
The superior articular process is placed near the 
base of the odontoid process. It is concave from side 
to side. Its outer half lies directly above the trans- 
verse process, projects in front, and faces upward. 
The inferior articular process is not placed beneath 
the superior but upon the lamina. It is inclined up,- 
ward, forward, and faces forward. 
The transverse process is placed beneath the supe- 
rior articular process. It extends abruptly downward 
and backward. The process is but faintly grooved 
above. Its foramen is directed outward. 
Structure.-The cancelli are figured by Luschka 
as more compact in the odontoid process than in 
the body. Humphry describes and figures this com- 
pactness as decided. The denser part forms a division 
between the more cancellous apex and the rest of the 
process. K. Bardeleben1 figures the process as almost 
entirely compact. Dr. C. T. Hunter has detected in 
the process a special arrangement of trabecular fibres 
beneath this compact tissue much weaker than those 
ordinarily met with in the interior of the other ver- 
tebrae. In the judgment of this observer the fre- 
quency of fracture at the neck is hereby explained. 
It is evident from the foregoing statements that the 
odontoid process is more compact than the rest of the 
axis, but that in the degree of its compactness and 
arrangement of the cancelli at its neck there is some 
variation.-Dr. Reid2 has recorded an instance of 
conical exostosis of the odontoid process which in- 
duced compression of the spinal cord and death. 
P. Devan3 reports a case in which the odontoid pro- 
cess which had been separated from the body of the 
axis by fracture, had united to the edge of the fora- 
men magnum, thus emphasizing the relation occa- 
sionally seen between these parts in the uninjured 
subject. 
Remarks.-As an exceedingly rare formation the 
tip of the odontoid process may be prolonged upward 
and articulate with the anterior border of the fora- 
men magnum. According to Luschka, the tip of the 
spinous process receives a distinct centre of ossifica- 
tion. 
The neck of the odontoid process is the weakest 
part of the bone, and that portion which is most fre- 
quently the seat of fracture. Humphry1 describes 
this as a very rare condition, he having seen but two 
examples. 
THE SEVENTH CERVICAL VERTEBRA. 
The seventh cervical vertebra presents the follow- 
ing peculiarities: The articular processes are almost 
vertical, are not supported by small columns, and do 
not lie directly one above the other. The foramen 
at its base does not transmit the vertebral artery. 
The body is without median projection. There is 
sometimes one-fourth of a facet for articulation 
with the head of the first rib. The lateral extension 
of the lower surface of the vertebra may be almost 
entirely absent. The spinous process is very large, 
resembles that of a dorsal vertebra, and is without 
a groove. While not bifid it is much larger than 
any other of the cervical series, and forms in the sub- 
ject a distinct prominence beneath the skin. From 
this feature the bone has received the name of the 
" vertebra prominens." The process gives attachment 
to the nuchal ligament. According to Luschka the 
spinous process is often fractured. It was once so 
found by this observer in the body of an epileptic pa- 
tient under circumstances suggestive of the fact that 
the lesion had occurred as the result of a fall during a 
convulsion. 
Remarks upon the Cervical Vertebras as a 
Whole.-The portion of the spine composed of the 
cervical vertebras is at once the most flexible and 
most varied in form, while the most constant in the 
number of its elements. 
The position of the cervical vertebras can be made 
out in a satisfactory degree in the living subject. The 
fact that the anterior surfaces of the bodies lie directly 
behind the pharynx and the beginning of the oesoph- 
agus enables the finger to freely define the position of 
the second to fifth vertebrae through the posterior 
wall of the pharynx. The rounded nodule on a level 
with the base of the uvula is the atlas. It varies in 
degree of prominence. It is not to be confounded 
with a transverse fold of induration seen in the same 
neighborhood in certain abnormal conditions of the 
pharynx. The smooth surface directly in view when 
the mouth is open answers to the axis, which extends 
from the position of the nodule to the tip of the epi- 
glottis. Behind the free portion of the epiglottis lies 
the body of the third vertebra ; behind, the fixed por- 
1 Beitrage zur Anatomie der Wirbelsaule, Jena, 1874, Faf. 1, 
fig. 23. 
2 Lond. and Edin. Journ. Med. Sci., 1843. 
3 Dublin Medical Press, Feb. 18, 1863. 
1 Log. cit. 131. 114 
THE BONES. 
tion of the cartilage, the fourth; behind the cricoid 
cartilage, the fifth and sixth. The atlas-nodule is 
always distinct in the adult; the remaining points are 
variable. In some subjects a uniform median keel- 
like ridge can be readily felt the entire length of the 
pharynx. 
The formation of pus behind the pharynx is some- 
times caused by diseased vertebras; and in necrosis 
of the atlas and axis portions of these bones have 
been ejected into the pharynx (see Pharynx). In 
like manner, after fracture of the odontoid process, 
the detached fragment has been known to escape by 
perforation of the pharyngeal wall. 
On the sides of the neck the transverse processes 
can be distinctly felt beneath the skin in emaciated 
subjects. The distance between the transverse process 
of the atlas and the angle of the lower jaw is not 
greater than half an inch. In dissection the process is 
not exposed until the anterior tendinous margin of the 
Stcrno-Cleido-Mastoid muscle is raised from over it, 
the tough fibrous tissue is removed, and a deep-seated 
lymphatic gland which is lodged below the process is 
pressed aside. The process in reality belongs, clini- 
cally speaking, to the region about and behind the 
angle of the jaw. Its condition should be carefully 
eliminated in making a diagnosis of tumors of this 
region. II. J. Bigelow1 believes that cystic tumors of 
the neck almost always arise from the parts about 
this transverse process and the styloid process of the 
temporal bone. The styloid process extends down- 
ward and forward one-third of an inch between the 
angle of the jaw and the transverse process. Further 
down the neck the transverse processes can be felt 
by deep palpation. They serve as valuable guides in 
making incisions for reaching the track of the great 
vessels in ligation, and for the position of the oesoph- 
agus in oesophagotomy. 
Posteriorly the third, sixth, and seventh spines can 
alone be felt. The remaining spines are thickly cov- 
ered by the soft parts. The apex of the lung answers 
to the spine of the seventh vertebra. It is about this 
spine that a peculiar neuralgic pain often radiates 
in anaemic persons. 
Specimens are occasionally met with in the collec- 
tions where the atlas and the skull become anchylosed. 
After fracture in this region the reparative process is 
active, so that union of the fragments takes place 
should the patient survive the immediate effects of 
narrowing of the vertebral canal. 
The deformations arising from malposition of the 
vertebrae are to be carefully separated from those due 
to muscular contraction or wry neck. 
F. R. Lente1 has reported the rare anomaly of a 
vertebral column possessing but six cervical verte- 
brae.2 
The Cervical Rib.-The anterior portion of the 
transverse process of the seventh vertebra bearing the 
anterior tubercle is sometimes imperfectly anchylosed 
to the body. When thus free it has received the name 
of the cervical rib, since it is homologous with a 
true rib. Its anterior extremity may be free or be 
joined to the first true rib. The presence of a cervi- 
cal rib may interfere with the normal relations of the 
subclavian artery, diminish the circulation of the 
upper extremity, or induce pressure upon the bra- 
chial plexus. An exostosis growing from such a rib 
was detected by Holmes Coate3 on the left side in a 
female aged 26. The condition was thought to be 
congenital, at least it had existed since early child- 
hood. The growth was successfully removed by 
operation. The circulation of the limb remained 
unimpaired. The cervical rib has been the subject 
of special memoirs by Halbertsma,4 Luschka,5 Struth- 
ers,6 Gruber,7 and Turner.8 
THE DORSAL VERTEBRAE. 
The dorsal vertebrae are the vertebrae of the chest 
or thorax. Each bone is distinguished by the pre- 
sence on the side of the body of a depression for the 
head of its associated rib. The two upper dorsals 
resemble the type of the cervicals, the lower dorsals 
resemble the type of the lumbar vertebras. Rudi- 
ments of the true transverse and mammillary pro- 
cesses are seen on the bodies of the eleventh and 
twelfth. 
The body, figs. 5 and 6, Plate XIII., is narrower in 
front than behind. From the third to the eighth the 
bodies are convex in front and concave behind to 
1 N. Y. Journ. of Medicine, 1850, 285. 
2 For an account of the homologies of the atlas, axis, and those 
of the occipital bone, in connection with these bones, see Cleland, 
Nat. Hist. Rev. Ap. 1861, also W. Allen, Journ. Anat, and Phys, 
xiv. 1879, 18. 
s Med. Times and Gazette, Ap. 3d, 1861, 108. 
4 Roy. Acad. Sci. Amsterdam, 1856, 238. 
6 Denkschriften der m. n. Klasse der Kais. Acad, der Wissen- 
schaften, Berlin, xvi. 
6 Ed. Monthly Med. Sci. xvii. 1853, 292. 
• Mem. Acad. Imper. St. Petersburg, xiii. 1869. 
8 Journ. of Anat, and Physiol, iv. 1870, 130. 
1 Bost. Med. and Surg. Journ., vol. Ixxxvii. 279. THE DORSAL VERTEBRAL 
115 
form the anterior border of vertebral foramen. In 
the last four the posterior surfaces are flat. 
The transverse sections of the bodies of the upper 
and lower vertebrae exhibit oval figures, while those 
of the middle are triangular, with sub-rounded 
angles. The anterior surface of each body is some- 
times called the visceral surface from its relation to 
the thoracic viscera, when the posterior becomes the 
vertebral, or spinal surface. The upper and lower 
surfaces are not parallel, but may be slightly inclined 
toward one another. 
The depression for the rib is variable in shape, but 
is for the most part of a modified semilunar figure. 
The upper nine vertebrae have for this purpose two 
demi-facets, one at the upper at the junction of the 
body and the lamina, at the other at the lower border 
of the body near the vertebral border. In the eleventh 
and twelfth ribs the single facet is placed more upon 
the lamina than in the others. 
The pedicle arises from the body at its upper half 
and at its side. While the lower border is rounded, 
the upper is sharp. At the same time the upper 
notch is shallow, and looks upward and inward, while 
the inferior is deep. In the first dorsal vertebra the 
pedicles are cylindrical. The upper notch is deep 
and semicircular, and looks upward. 
The laminae are broad and thin, and soon unite to 
form the broadly-based spinous process. At the 
pedicles the laminae are horizontal; but beyond the 
superior articular process of each side the laminae are 
deflected abruptly downwards on the same plane with 
that of the spinous process. 
The superior articular processes are both nearly on 
the same plane with the laminae, and look backward. 
The inferior articular processes look forward, excepting 
those of the twelfth vertebra, which look laterally. 
The so-called transverse process is a conspicuous robust 
projection, nearly as broad as the body. It is directed 
laterally and a little backward. Its anterior surface 
is rounded by a facet for articulation with the cor- 
responding rib. The true transverse process, viz., 
that which is homologous with the posterior tubercle 
of the cervical vertebrae, is not seen in the dorsal ver- 
tebrae until the tenth and eleventh are reached as 
already mentioned. In the lumbar vertebrae they 
again appear. 
The Dorsal Vertebrae as a whole.-When the 
twelve dorsal vertebrae are articulated they are seen 
to form a column whose anterior surface is concave. 
The spinous processes, notwithstanding their rela- 
tively great length, project not directly backward, but 
obliquely downward and backward. The laminae 
thus overlap-less at the beginning and the end of 
the column than toward its middle. A degree of 
strength is thus secured to the dorsal region over and 
above that secured by the articular surfaces against 
one another, while the vertebral canal receives an 
additional protection. The ribs still further aid in 
protecting and fixing the dorsal region, which is as a 
result the best preserved from injury, while the most 
rigid, of any portion of the spine. Exostoses of the 
vertebral canal are rare. Humphry1 mentions a 
case in which a bony outgrowth had projected from 
the hinder surface of one of the dorsal vertebrae and 
had pressed upon the cord, inducing paralysis of the 
lower extremities. 
THE LUMBAR VERTEBRAL 
The lumbar vertebras are the vertebras of the loins. 
Each bone (figs. 7 and 8, Plate XIII.) possesses a 
massive body, which is wider from side to side than 
from before backwards. Its nutritive foramina are 
more conspicuous than in other vertebrae. These are 
especially well developed upon the posterior surface, 
where they form two openings for the basi-vertebral 
veins upon either side of a faint median ridge. The 
latter is often absent, when the openings are confluent. 
The laminae are correspondingly massive with the 
body. The pedicles arise from the upper half or two- 
thirds of the body. They are short, but heavy, and 
support the transverse and superior articular pro- 
cesses. These latter structures may be studied in the 
following order: The transverse process (homologous 
with a rudimentary rib) arises from the outer side 
of the pedicle at the base of the superior articular 
process. It is broad and compressed laterally, and is 
directed outward and backward. The superior articu- 
lar process presents a concave facet directed inwards 
and backwards. The outer surface of the process 
yields at its posterior border a rounded eminence pro- 
jecting backward beyond the facet, the mammillary 
process for the origin of the slip of the Multifides 
Spinae muscle. Behind the base of the transverse 
process is seen the accessory process, which is a faint 
ridge-like projection representing a rudiment of the 
transverse process of the dorsal vertebrae. • 
The spinous process is very broad, directed horizon- 
tally backward from the laminae. It is thin above, 
broad below, whence its contours are continuous with 
the inferior articular processes. The latter are nearer 
1 Human Skeleton, 157. 116 
TH Pl BONES. 
one another than are the upper. They are deflected 
at a right angle from the lamina of its own side. The 
facets are vertical, slightly convex, and look outward 
and backward. 
The vertebral canal is triangular, with sub-rounded 
angles, or is lozenge-shaped. 
The curve of the lumbar column is very slight, and 
is so directed as to be convex forward. To this effect 
both the bones and the shapes of the intervertebral 
disks contribute. 
Friction facets are often seen between opposed bor- 
ders of the spinous processes, and occasionally a dis- 
tinct interspinous joint forms. The fifth vertebra is 
deeper at the anterior than at the posterior margin. 
The transverse processes lie in a series with the lower 
so-called transverse processes and with the ribs of the 
dorsal vertebrae. 
REMARKS ON THE VERTEBRAL COLUMN AS A WHOLE. 
The applications to practice that can be made of a 
knowledge of the anatomy of the vertebral column 
are numerous and important. 
It is necessary to remember that the spine is secured 
in position by the joints between the vertebrae. The 
variations of the shape of the column are due to the 
dispositions of the joints as well as of the bones. 
Destruction of the bodies of the vertebrae so far in- 
terferes with the lines of support already mentioned 
as to throw the weight of the superimposed mass 
upon the laminae. These are not adapted to sustain 
such weight, save only in the cervical vertebrae; and 
when, as is frequently the case, the dorsal vertebrae 
are involved, the drag of the ribs, sternum, and their 
muscular and visceral attachments create an exagge- 
rated antero-posterior curvature of the dorsal verte- 
brae, ending in deformity not only at the portion of 
the spine thus yielding, but in others, so that a group 
of secondary changes in the entire vertebral column 
arise, distorting or obliterating the normal curves. 
Rosian, according to Portal,1 has found a greater 
tendency to displacement on the parts of the bones of 
the vertebral column to exist between the last dorsal 
and the first lumbar vertebra than elsewhere. Jeffries 
Wyman,1 in reaffirming that the lumbar region is the 
weakest portion of the lumbar arch notwithstanding 
its increased bulk when compared to the other re- 
gions of the spine, uses the following language:- 
"In dorsal vertebrae the arches are characterized by 
the breadth of the laminae and by having the trans- 
verse processes implanted just between the articular 
ones, where, in consequence, the arch becomes greatly 
strengthened, in fact, has its greatest strength. In 
the lumbar region the transverse processes are thrown 
further forward, so as to rest more upon the pedicle, 
while the upper and lower articulating ones become 
more widely separated from each other, the lower 
ones being carried downwards, and the bone connect- 
ing them so contracted as to form a somewhat slender 
neck ; thus the part in question becomes the weakest 
instead of the strongest portion of the arch." 
Malgaigne, while recognizing the weak point above 
defined, gives two others, one at the junction of the 
cervicals and the dorsals, and the other at the junction 
of the lumbar vertebrae and the sacrum;-in a word, 
including aZZthe vertebrae of transition. 
Humphry has cited a number of related causes in 
explanation of the same group of facts. Since, for ex- 
ample, "the transverse processes being very short, 
while the long transverse processes in the lower part of 
the loin, added to the projecting crest of the ilium 
below, and the false and true ribs above, afford to the 
several muscles a powerful leverage acting upon this 
junction on either side and in front. It is near the mid- 
dle of the column, so that a greater length of leverage 
can be brought to bear against it than atany other part." 
The next weakest point in the vertebral column is 
the dorsal region. Fracture is relatively frequent 
here, and, as already stated, antcro-posterior curvature 
of the spine is common. 
Dr. D. J. Cunningham2 has observed a vertebral 
1 Anat. Med. I. 295, note. 
1 Bost. Med. and Surg. Journ. 1869. 
2 Journ. Anat, and Phys. 1878, 89. 
EXPLANATION OF PLATE XIV. 
Fig. 1. The sacrum, seen from in front. 
The reader should read the word " promontory" as referring 
to the anterior surface of the first sacral vertebra at its upper 
part. 
Fig. 2. The sacrum, seen from the side. 
Instead of " for sacral vertebra," read " 1st sacral ver- 
tebra." 
Fig. 3. The sacrum, seen from behind. 
Fig. 4. The coccyx, seen from behind. Fig.l 
PLATE XIV 
Fig. 2 
Fig. 3 
Fig. 4 
T. .Sincl air & THE LUMBAR VERTEBRAE. 
117 
column in which the epiphysial processes of the mam- 
millary processes of the twelfth dorsal remained dis- 
tinct; as also did the fused mammillary and accessory 
processes of the first lumbar vertebra. The spinous 
process of the first dorsal and the transverse process 
of the seventh dorsal in like manner presented de- 
tached epiphysial bones. 
THE SACRUM. 
The sacrum (figs. 1, 2, 3, Plate XIV.) is formed by 
the fusion of the five vertebrae which intervene be- 
tween the lumbar vertebrae and the coccyx. The 
lines of union of the bodies of the vertebrae can be 
distinguished in front by four transverse ridges repre- 
senting the position of the ossified intervertebral 
disks; and behind by a median row of tubercles 
which represent the dorsal vertebral spines. The in- 
tervertebral foramina are seen under the name of the 
sacral foramina; and the vertebral canal under the 
name of the sacral canal. 
The sacrum is the broadest part of the vertebral 
column, and forms the posterior wall of the pelvis. 
The bone has been compared to a wedge. Its antero- 
posterior curvature impairs the value of this figure 
somewhat. The first sacral vertebra closely resembles 
the last lumbar vertebra both in appearance and in size; 
the remaining segments gradually lose resemblance to 
vertebras, the last, indeed, retaining little beyond a 
body and imperfect laminae. 
The sacrum presents for examination a base, an 
apex, and anterior, posterior, and lateral surfaces. 
The base has a broad surface, which corresponds to 
the body of the last lumbar vertebrae, and a pair of 
well-defined sacral articular processes which join the 
inferior lumbar processes of the same name. The 
apex is small, and articulates with the coccyx by a 
narrow oval surface. 
The anterior surface (fig. 1, Plate XIV.) is concave 
and nearly smooth. It is ridged transversely by the 
four lines of union between the several vertebrae. The 
spaces between the terminations of these ridges and 
the lateral surfaces are called the lateral masses, and 
are marked by four broad and shallow grooves for the 
anterior sacral nerves. The anterior upper portions 
of the sacrum are often spoken of as the wings or alee. 
The Pyriformis muscle arises from the lower two- 
thirds of the lateral mass, and the Coccygeus arises in 
part from its inferior portion. 
The posterior surface (fig. 3, Plate XIV.) is narrower 
and more irregular than the anterior. The laminae, 
dorsal spines, articular and transverse processes unite 
with one another without suture, thus covering in the 
sacral canal except at a small space behind the first 
and last sacral vertebrae, where, as a result, the supe- 
rior and inferior sacral notches, respectively, are de- 
fined. The laminae blend to form a continuous surface 
on either side of the median row of tubercles which 
are the rudiments of the dorsal spines. This surface 
would be smooth throughout,were it not for the nodosi- 
Tabular Plan of Parts opposite the Spines of 
the Vertebra. (Holden.) 
o 
Ph 
o 
7th. Apex of lung ; higher in the female than 
in the male. (30) 
1st. 
2d. 
3d. Aorta reaches spine. Apex of lower lobe 
of lung. Angle of bifurcation of tra- 
chea. (49) 
4th. Aortic arch ends. Upper level of heart. 
5th. 
6th. 
7 th. 
8th. Lower level of heart. Central tendon of 
diaphragm. 
9th. (Esophagus and vena cava through dia- 
phragm. Upper edge of spleen. 
10th. Lower edge of lung. Liver comes to 
surface posteriorly. Cardiac orifice of 
stomach. 
11th. Lower border of spleen. Renal capsule. 
12th. Lowest part of pleura. Aorta through 
diaphragm. Pylorus. 
tn 
£ 
E 
UI 
J 
tn 
M 
O 
Q 
1st. Renal arteries. Pelvis of kidney. (83) 
2d. Termination of spinal cord. Pancreas. 
Duodenum just below. Receptaculum 
chyli. 
3d. Umbilicus. Lower border of kidney. 
4th. Division of aorta. (65) Highest part of 
ilium. 
5th. 
9 
- 
According to the same authority, the spine of the 
second dorsal corresponds with the head of the third 
rib; the spine of the third dorsal with the head of 
the fourth rib; and so on until we come to the eleventh 
and twelfth dorsal vertebras, which so tally with their 
corresponding ribs.1 
1 For other relations, see Tabular Relations between the anterior 
and posterior surfaces of the thorax. 118 
THE BONES. 
ties which stand for the pairs of coalesced articular and 
mammillary processes of the sacral vertebra?. They 
are ranged in a linear series between the more con- 
spicuous dorsal spines and the posterior sacral fora- 
mina. The terminations of the line of articular pro- 
cesses form noticeable projections; the inferior of these 
are called the sacral cornua. To the outer side of these 
foramina are placed the less perfectly marked remains 
of the lumbar transverse processes. By reason of 
these numerous modifications of the vertebra?, the 
vertebral grooves are shallow and imperfectly defined. 
The posterior sacral foramina are much smaller than 
the anterior, and are not accompanied with grooves. 
The posterior surface gives origin to the Gluteus 
Maximus and Coccygeus muscles, and to the vertebral 
aponeurosis. 
The lateral surfaces (fig. 2, Plate XIV.) are di- 
vided into two portions, which differ widely in their 
degrees of departure from the vertebral plan. Each 
surface answers to the sides of the first three vertebras, 
is broad and thick, and in the fresh condition of the 
bone is occupied by an ear-shaped surface of cartilage 
(auricular surface) for articulation with the corre- 
sponding innominate bone. Below the auricular sur- 
face the lateral surface is compressed, notched, and 
without articulation. Above, it affords attachment 
to the sacro-sciatic ligament. 
Viewed as a portion of the spinal column the sacrum 
presents an abrupt anterior convexity opposite the 
first sacral vertebra, called the promontory of the 
sacrum. This eminence may so vary as to be opposite 
to the second sacral vertebra. Below this is a gentle 
concavity, which assists in forming the superior outlet 
of the pelvis, and in supporting the pelvic viscera. 
In uniting with the lumbar vertebra an opening of 
variable size is formed between the laminae of the 
vertebrae and the first dorsal tubercle of the sacrum. 
Hence the vertebral canal is not well protected at this 
point. When from any defect in the development of 
the posterior surface this opening is preternaturally 
large, we have the condition known as spina bifida. 
Spina bifida may in this way be confined to the upper 
portion of the sacrum, or it may involve the entire 
bone and even the lumbar vertebrae. In addition to 
the above the union converts the supra-intcrvertebral 
notch into a foramen of the same name. Union with 
the coccyx converts the intervertebral notch at the 
lower border of the sacrum into a foramen ; and union 
with the innominate bone converts the notch at the 
lower border of the lateral surface into a foramen 
which transmits the fifth sacral nerve. 
Development.-The sacrum develops after the 
manner of the vertebrae, of the elements of which in- 
deed it is composed. Thus there is one centre each 
for the bodies of the vertebrae, and one each for the 
laminae posteriorly, as well as for the tubercles which 
answer to the mammillary tubercles of the lumbar 
vertebrae. Epiphyses, similar to those seen elsewhere 
in the vertebral column, arise upon the bodies of the 
vertebrae. In addition to these vertebral characteris- 
tics the sacrum presents a new ossification upon its 
lateral surfaces. These are two in number on each 
side, and resemble generally the epiphyses upon the 
vertebrae. The following is the order in the devel- 
opment of the parts of the sacrum:- 
Ossification takes place in the bodies and laminae at 
the eighth or ninth week; the laminae begin to ossify 
at the sixth month; the union of the laminae with 
the body in the lower vertebrae occurs in the second 
year, and in the upper later, namely, at about the 
fifth or sixth year. The epiphysial and lateral plates 
are formed at the sixteenth year, and completed at 
the twenty-fifth. The bodies of the sacral vertebrae 
unite slowly. The process is completed from below 
upward, as with the laminae, at about the twenty- 
fifth year. (Quain.) 
Articulations.-The sacrum articulates with the 
last lumbar vertebra above, the coccyx below, and 
the innominate bones at the sides. 
Remarks -The promontory of the sacrum can be 
readily felt by rectal examination. 
EXPLANATION OF PLATE XV 
Fig. 1. The vertebral column, seen from the side. 
Fig. 2. The dorsal vertebra? and portions of ribs in position, 
showing the method of union between the ribs and the 
vertebras. From a dried preparation. The curve of 
the column is distorted, and the lines of union of the 
heads of the ribs with the vertebrae are too irregular. PLATE XV 
Fig 1 
F^-2 
T. Sinclair & S on.Lith- THE BONES OF THE HEAD. 
119 
The base of the sacrum is about on the level of the 
anterior superior spinous processes; the position of 
the promontory can thus be accurately determined. 
THE COCCYX. 
The coccyx is composed of the rudiments of four 
vertebrae. This number may be increased to five, or 
even be reduced to three. The coccyx has neither 
arches nor spinal canal. The bones arrange themselves 
in a series resembling that seen in the sacrum, inas- 
much as the first is the largest, and the last is the 
smallest: the resultant figure is therefore wedge- 
shaped. The first vertebra is usually distinct, while 
the remaining are co-ossified, the limiting ridges alone 
indicating the lines of union. The first vertebra pos- 
sesses a pair of ascending processes {the coccygeal 
cornua), posteriorly, which are in the line with the 
articular processes of the sacrum, and which may 
be considered to be rudiments of the laminae. Well- 
defined rudiments of transverse processes exist in 
this member of the series alone. 
The second and third coccygeal vertebrae are much 
compressed from above downward, and triangular in 
form ; while the remaining portion of the bone is 
pyriform. The first coccygeal vertebra unites with 
the second, and also with the sacrum in the adult 
period. Such union is subject to much variation. 
An intervertebral disk exists ordinarily between the 
coccyx and the sacrum. 
Development.-The coccyx arises from four cen- 
tres of development. Ordinarily each bone arises 
from a distinct centre ; the upper may arise from two. 
The first becomes osseous at birth; the second at 
from the fifth to the tenth year; the third before 
puberty; and the fourth after puberty. 
Remarks. - The coccyx can be readily felt by 
rectal or even vaginal examination. It has been 
often fractured by external violence; and in par- 
turition, where marked sacral curvature exists, it is 
often either fractured or displaced. The greatest in- 
terest centring about the coccyx relates to the painful 
affection known as coccygodynia. In connection 
with the structural changes associated with this dis- 
ease the student should carefully study the ligaments 
and nerves of the coccyx, and the muscles inserted 
into it, as well as the position of the coccygeal body. 
Among the causes of this affection may be mentioned 
inflammation of the bone and ligaments, contracture 
of the muscles, and enlargement of the coccygeal 
body. Verneuil1 proposes to remove the coccyx as a 
preliminary procedure to perineal section in cases of 
imperforate rectum. The assertion is made that the 
operation is without danger. 
For the relation existing between the curvature of 
the sacrum with the coccyx and the genital cleft, see 
the account of the female organs. 
THE BONES OF THE HEAD. 
The skull is composed of two sets of bones: one 
defines the brain-case and constitutes the cranium 
proper; and the other defines the nasal and orbital 
cavities, at the same time affording protection to the 
teeth, and constitutes the face. 
The bones of the cranium are eight in number,-• 
The occipital, The two parietals, 
The two temporals, The frontal, 
The sphenoid, The ethmoid. 
The bones of the face are fourteen in number,- 
The vomer, 
The two superior maxillae, 
The two palatals, 
The two inferior turbinated bones, 
The two malars, 
The two lachrymals, 
The two nasals, 
The inferior maxilla. 
All the bones of the head, with the exception of 
the inferior maxilla, are immovably united together. 
THE OCCIPITAL BONE. 
The occipital bone (figs. 1, 2, 3, Plate XVI.; also, 
fig. 2, Plate XXXVI.) is situated at the base and 
posterior part of the cranium. It is slightly curved 
from above downward, and seen in profile is of a 
crescentic figure. The part of the figure in advance 
of the conspicuous condyles passes upward and for- 
ward, and forms the basilar portion of the bone ; that 
to the outer side of the condyles forms the lateral 
portion; and that behind, passing backward and up- 
ward, forms the ascending portion. Between the 
condyles, and extending thence backward, lies the 
foramen magnum. This is a large oval foramen, 
somewhat longer than wide, and wider behind than 
in front. 
The occipital bone articulates with the sphenoid bone 
and with the parietal and temporal bones. It affords 
1 Gaz. des Hopitaux, Nos. 87 and 90, 1873. 120 
THE BONES. 
pairs of nerves. At the beginning of the occipito- 
mastoid junction is a broad transverse process (jugular 
process), which is tipped in the recent subject with 
cartilage. Upon the under surface of the lateral por- 
tion, and corresponding at the same time to the under 
surface of the' transverse process, is the jugular tu- 
bercle, for origin of the Rectus Lateralis muscle. Upon 
the under surface in front of the condyle lies the 
anterior condyloid fossa, which is pierced by the ante- 
rior condyloid foramen (hypoglossal canal) for the 
transmittal of the hypoglossal nerve. Behind the 
condyle is seen a depression {posterior condyloid fossa}, 
which is commonly perforated by the smaller poste- 
rior condyloid foramen for the accommodation of the 
posterior condyloid vein. The superior surface of the 
lateral portion is marked by the lateral sinus, as it 
passes downward to empty into the internal jugular 
vein. Upon the encranial surface and over the course 
of the anterior condyloid foramen is seen a bridge 
of bone, called the jugular eminence. -• The large 
occipital condyles are placed one on each side of the 
foramen magnum. The articular surface of each 
condyle is elliptical in form, and directed obliquely 
downward and inward. The anterior edge of the 
articular surface rests on a rounded border that is an- 
gulated to the plane of the anterior condyloid fossa 
and that of the basilar process. The posterior por- 
tion of the articular surface lies on a level with 
the posterior condyloid depression, and thus presents 
a marked contrast to the anterior. The inner surface 
of each condyle is uneven for attachment of the check 
ligaments. Each articular surface is composed of two 
facets of about equal dimensions, an anterior and a 
posterior. These facets are occasionally separated by 
a transverse groove. 
The ascending portion of the occipital bone is a 
scallop-shaped expansion. It is convex externally, 
concave internally. The borders are thickened, and 
articulate by serrated surfaces with the parietal 
and temporal bones. The ascending portion joining 
protection to the cerebellum and the occipital lobes 
of the cerebrum within, and yields points of origin to 
important bones without. In advance of the condyles 
it assists in forming the roof of the pharynx; and be- 
hind in defining the occiput and post-atlantal space. 
The foramen magnum transmits the medulla oblon- 
gata, the vertebral arteries, and the spinal accessory 
nerves. These structures do not entirely occupy the 
opening, the space between the medulla and the mar- 
gin being filled by the cerebro-spinal fluid. 
The basilar portion of the occipital bone is an oblong 
figure, and abruptly truncate in front, where it joins 
the body of the sphenoid bone. It is wedge-shaped- 
the base of the wedge constituting the surface that 
articulates with the body of the sphenoid, the edge 
forming in great part the anterior margin of the fora- 
men magnum. The basilar process presents four sur- 
faces for examination: an anterior and a posterior, 
just mentioned; a superior, which is concave and 
smooth to receive the medulla oblongata and the basi- 
lar artery; and an inferior, which is more irregular, 
and which is marked as follows: from before backward, 
first by a median minute circular depression, not con- 
stantly present; second, by the pharyngeal tubercle for 
the attachment of the pharyngeal aponeurosis; third, 
by the symmetrical depressions directly in advance of 
the occipital condyles, for the Anterior Recti muscles. 
The lateral (outer) surface of the basilar portion is 
uneven, and articulates at its upper portion with the 
petrous portion of the temporal bone. Seen in posi- 
tion in the skull, the greater part of the under surface 
of the basilar process is free, and is covered by a dense 
fibrous tissue during life. 
Each lateral portion is joined anteriorly by the 
basilar, superiorly by the ascending portion of the 
bone. It joins externally the mastoid portion of the 
temporal bone. Upon its lateral side is a deep de- 
pression, jugular notch which receives the jugular 
vein. Directly in front of the jugular notch is seen 
a smaller excavation for the ninth, tenth, and eleventh 
EXPLANATION OF PLATE XVI. 
Fig. 1. The occipital bone, seen obliquely from the side. 
Fig. 2. The occipital bone, seen from beneath. 
Fig. 3. The occipital bone, seen from in front. 
Fig. 4. The temporal bone, seen from beneath. 
Fig. <5. The temporal bone, seen from median aspect. 
The petrous portion is represented as foreshortened from 
in front. 
Fig. G. The temporal bone, seen from lateral aspect. 
The words " Ext. Auditory meatus," should not have 
been engraved in capitals. PLATE XVl 
Fig .1 
Fig.2 
Fig.4 
Fig 6 
Fig 5 
T Swelair&Sau.liih THE BONES OF THE HEAD. 
121 
the parietals behind the sagittal suture has received 
the name of the occipital angle, and the portion occu- 
pying the space between the two parietals the inter- 
parietal portion. On the external surface, a little less 
than midway between the base and the angle, is seen 
the external occipital protuberance for the attachment 
of the ligamentum nuchse. It may form a conspicuous 
triangular process projected downward. The surface 
above the protuberance is smooth, and is curved in 
the subject by the aponeurosis of the Occipito-Frontal 
muscle; the surface below it is more uneven, and is 
marked by muscular impressions pertaining rather 
to the basal region of the skull. Extending from the 
occipital protuberance downward is a faintly defined 
ridge, the occipital crest. On either side of the crest are 
strongly marked impressions for the Complex us mus- 
cles. Bordering these above lies the superior curved 
line for the attachment of the Trapezius, Occipito- 
Frontalis, and the Sterno-Cleido-Mastoideus muscles. 
On a level with the Complexus impressions, but ex- 
ternal to them, lie the planes of origin of the Splenius 
Capitis and Obliquus Superior muscles. The inferior 
margin of the Complexus impression is known as the 
inferior curved line. The space between it and the 
foramen magnum is occupied by the Rectus Capitis 
Postici muscles. 
The internal surface (fig. 3, plate XVI.) of the as- 
cending portion is deeply concave and smooth. At a 
point nearly corresponding to the external occipital 
protuberance lies the internal occipital protuberance. 
Passing thence downward, a little to the right of the 
median line is seen the groove for the great longitu- 
dinal sinus as it assumes a more horizontal position 
to form the groove for the lateral sinus. A fainter 
groove on the opposite side answers to the left lateral 
sinus. A smaller and inconspicuous sulcus for the 
occipital sinus extends from the protuberance down- 
ward to the foramen magnum, in approaching which 
it is apt to bifurcate. The large depressions on either 
side of the median line above and below the grooves 
for the lateral sinuses form collectively the occipital 
fossa. The upper two depressions receive the poste- 
rior lobes of the cerebrum; the lower receive the 
hemispheres of the cerebellum. 
Structure.-The basilar process of the occipital 
bone from the margin of the foramen magnum to nearly 
half its length is composed of compact tissue ; beyond 
this point it divides into an upper and a lower plate, 
of which the lower is the thicker: the space between 
the plates is occupied by cancelli. The lateral por- 
tions are for the most part spongy, and indeed in the 
aged the region of the jugular process becomes hollow. 
The ascending portion above the superior semicircular 
line is thick, and furnished with abundant diploe. It 
is thickest toward the occipital angle. Below the 
internal occipital protuberance, on either side of the 
occipital groove, the bone is thin and compact. 
Development.-The occipital bone arises from 
seven centres. The basilar and lateral portions exist 
as cartilage prior to ossification. Ossification begins 
at about the seventh or eighth week; thus recalling 
the period at which the osseous centres appear in the 
bodies and the laminaa of the vertebras. A little 
earlier the ascending portion of the bone, which is 
membranous, yields four centres of ossification, two 
on either side. These soon unite toward the centre 
to form the ascending portion of the bone, but leaving 
pronounced fissures extending inward from the periph- 
ery. At birth the bone is composed of the ascending 
portion, of the lateral or exoccipital portions, and of 
the inferior or basilar portions. The ascending and 
lateral portions join at about the second and third 
year; the basilar and lateral portions by the fifth or 
sixth year. The basilar portion unites with the 
body of the sphenoid bone between the fourteenth 
and the twentieth year. 
The suture between the lateral and ascending parts 
near the posterior border of the condyles begins to be 
obliterated at the end of the first year. At the end 
of the second the obliteration is nearly complete-a 
small fissure at the border of the foramen magnum 
often persisting until the seventh year. It is rare 
for the entire suture to remain open during this time. 
The anterior portion of the interoccipital persists 
quite constantly until the seventh year. 
Remarks.-The occipital bone is the most variable 
of any in the skull. The entire interparietal portion 
often projects backward from the vault-curve, and con- 
stitutes a frequent variety of cranial deformity. The 
angular process sometimes assumes the form of a dis- 
tinct bone. Portal alludes to the fact that, in injuries 
of the skull, this portion has been known to be de- 
pressed and to impinge upon the meninges.-A con- 
spicuous tubercle on the anterior margin of the fora- 
men magnum is occasionally seen. In about one per 
cent, of crania the odontoid process of the axis secures 
an articulation with a facet on the anterior margin of 
the foramen magnum ; this facet is termed the tertiary 
condyle.-The interparietal portion may contain a large 122 
THE BONES, 
foramen in the median line, which may be assumed 
to answer to defective nutritive processes at the line 
between the first upper pair of centres of ossification 
of the ascending portion.-The entire angle may be 
defective, and may permits hernia of the cerebrum to 
occur through the opening. It is interesting to note 
that in a case of this kind, recorded by Detmold,1 a 
median depression existed in the hernial mass; this 
answered in position to the falx cerebri, which thus 
aided in modifying the shape and limiting the degree 
of the projection of the hernia. 
The surface occupied by the jugular tubercle is the 
seat occasionally of a peculiar hypertrophy, which, 
occupying as it does the position of the paramastoid 
process in the lower animals, may receive this desig- 
nation. The paramastoid process will sometimes ap- 
pear in aged persons, where, from the fact that it is 
occupied by a few coarse cancelli, and that it thus re- 
sembles lung structure, it has received the name of 
the pneumatic process. The presence of the paramas- 
toid process may induce one of the varieties of wry 
neck,2 especially when it is attached to the transverse 
process of the atlas. 
That the roof of the pharynx, which in the living 
subject answers in position to the basilar process, can 
be reached by passing a straight instrument through 
the nose, is a clinical test easy of demonstration. 
Winslow refers to a charlatan's trick of introducing 
a long nail through the nasal chamber as far as the 
basilar process, and attaching to the outer end of the 
nail a heavy weight. The process in this trial of 
strength acts as a point of resistance to the extremity 
of the lever, and is enabled from the direction of the 
pressure to bear the weight.-The basilar process 
may be easily pierced from beneath by a missile or 
other foreign body introduced through the nose or 
mouth. Of this injury the following case is a striking 
example: A little girl fell down while holding a 
wooden crochet-needle in her mouth. The needle 
transfixed the uvula, passed through the basilar pro- 
cess directly in front of the foramen magnum, and 
made a punctured wound of the medulla oblongata. 
Death ensued in three days.3-Caries of the basilar 
process has been diagnosed by Paget4 in a male 
twenty-seven years old. An abscess formed at the 
nape of the neck, through the cavity of which a 
sequestrum from about the foramen magnum was 
removed. Through pressure upon the hypoglossal 
nerve the tongue was atrophied and deflected. The 
patient recovered.-Dupuytren1 describes a case in 
which a hydatid cyst was lodged within the hypo- 
glossal canal, causing symptoms similar to those of 
the previous case.-The foramen magnum may be 
either compressed laterally or greatly widened. There 
is preserved in the Mus6c Dupuytren a skull of an 
infant in which the foramen magnum is sufficiently 
large to have permitted a hernia cerebelli to appear 
upon the neck-a fact of unusual interest, since the 
tumor was mistaken for a cystic growth, and opened, 
with a fatal result.-In rachitis, the lateral portions of 
the occipital bone become flattened, forming a condi- 
tion termed by Elsaesser the soft occiput.-Solborg2 
found in nine cases of epilepsy a constriction of the 
spinalcana], from hypertrophy of the jugular process 
of the occipital bone and of the posterior necks of the 
atlas and axis, with secondary atrophy of the medulla 
oblongata. 
THE TEMPORAL BONE. 
The temporal bone (figs. 4, 5, 6, Plate XVI., also 
fig. 4, Plate XXII.) is situated at the side and base of 
the cranium, having the lateral portion of the occipital 
bone behind, the great wing of the sphenoid in front, 
the axis of the cranium within, and the temporal 
fossa, for the most part, without. Beneath is an ir- 
regular surface marked by the mastoid, styloid, and 
vaginal processes, and the glenoid fossa. 
The bone, as generally described, presents for ex- 
amination the squamous, the petrous, and the mastoid 
portions, but the significance of its several divisions 
cannot be in this way explained. It is better to divide 
the bone into parts that answer to the developmental 
centres. These are four in number, viz., the squamous, 
the petrous, the tympanic, and the styloid portions. 
To these may be added a fifth, the mastoid portion, 
for although the latter is not a true division of the 
bone (composed, as it is, of elements obtained from 
the squamous and the petrous portions), it is expe- 
dient to retain the term. 
The squamous portion (squama) is the most con- 
spicuous of these divisions when the bone is viewed 
in position from without. 
Externally the squamous portion is composed of 
the squama, or ascending part, the zygomatic or 
horizontal part, and the glenoid fossa. The squama 
forms the greater part of the temporal fossa. It is 
1 N. Y. Journ. of Medicine, 1856, xvi. 77. 
2 C. F. W. Uhde, Archiv fur Klinische Chirurgie, 1867, 24, Tab. 
1, Literature. 
3 P. I. Kendrick, Med. Times and Gazette, 1867, 585. 
4 Trans. Clin. Soc. London, iii. 283. 
1 Lemons Orales, i. 493. 
2 Rosenthal, Diseases of the Nervous System, ii. 63. THE BONES OF THE HEAD. 
123 
received in front by the greater wing of the sphe- 
noid bone, above by the parietal, and is limited be- 
hind by the ridge forming the posterior margin of 
the temporal impression, viz., the supra- mastoid 
ridge. The squama is smooth, slightly convex, and 
covered in the subject by the temporal muscle. The 
zygomatic or horizontal portion lies upon the base 
of the skull. The glenoid fossa is a depression for 
articulation with the lower jaw. It lies upon the 
base of the skull, and is defined in front by a faint 
ridge, behind by the glenoid fissure (squamoso-tympanic 
suture}, and by a dependent ridge, the post-glenoid pro- 
cess. From the junction of the squamous and zygo- 
matic surfaces arises a large process called the 'zygo- 
matic. This has a broad triangular origin from three 
roots. Its large posterior root is continuous with the 
post-glenoid process, its short anterior root is lost in 
the zygomatic surface, while its third, less defined, is 
received upon the under surface of the base of the 
process in a conspicuous convexity, the articular emi- 
nence. The zygomatic process extends horizontally 
forwards to articulate with the zygomatic process of 
the malar bone, and to form the zygomatic arch. The 
Masseteric muscle arises in part from this process. 
Internally, the squamous portion is concave, and 
marked by several inequalities designed to give in- 
creased strength to the bone. It is grooved for the 
meningeal arteries, and receives the middle lobe of 
the cerebrum. Inferiorly an eminence is seen corre- 
sponding to the glenoid fossa. 
The petrous portion is of an irregular pyramidal 
figure, the base of which is directed outward, the 
apex forward and inward. It is composed for the 
most part of very compact tissue, from which it de- 
rives its name. It contains the internal ear, transmits 
the facial nerve and internal carotid artery, and sup- 
ports in part the cartilaginous portions of the Eusta- 
chian tube. It presents for examination three sur- 
faces, an anterior and a posterior, which lie within 
the cranium, and an inferior, which lies at the base 
without. 
The anterior surface is divided into two sub-equal 
areas. The upper portion is of petrous consistency, 
and corresponds to the bony covering of the labyrinth. 
It is marked as follows: (1) An eminence for the 
vertical semicircular canal; (2) A depression toward 
the apex for the ganglion of Gasser; (3) A small de- 
pression entering into the formation of the foramen 
caroticus internus. The lower portion is a thin layer 
of bone (tegmen tympani}, which covers in the tym- 
panum and forms the roof of the bony portion of the 
Eustachian tube. It is continued forward to the 
sguamoso-petrosal fissure, and appears beneath at the 
glenoid fissure. The roof of the tympanum is per- 
forated by one or more minute openings, the most 
conspicuous of which is the hiatus Fallopii, for the 
greater petrosal nerve, and a smaller one for the lesser 
petrosal. At times a clot of blood occupying the 
chamber of the tympanum will be evident (after the 
removal of the brain) by the bluish discoloration of 
the tegmen. 
The posterior surface is less oblique than the an- 
terior, and presents a division into two planes: an 
outer, which is marked by a small foramen directed 
outward, the aquseductus vestibuli, which transmits 
venous blood from the internal ear; and an inner, 
which is nearly continuous with the plane of the basi- 
cranial axis. The latter is marked by the internal 
auditory meatus for the passage of the seventh and 
eighth cranial nerves. Upon the ridge between the 
anterior and posterior surfaces is a groove for the supe- 
rior petrosal sinus, which extends in a straight line as 
far as the internal auditory meatus, from which point 
it is deflected forward. From the meatus to the end 
of the petrous portion, the ridge is depressed for 
the reception of a thick fold of dura mater, beneath 
which pass the third, fourth, fifth, and sixth nerves. 
A distinct ossicle is occasionally found in this fold. 
The inferior surface (fig. 3, Plate XXIV.) of the 
petrous portion is covered in part by the tympanic 
and styloid portions. As seen from the base of the 
skull, the petrous portion presents a posterior border 
for articulation with the occipital bone, marked from 
without inward by the following parts: First, by a 
smooth triangular surface directly behind the styloid 
process for articulation with the transverse process of 
the occipital bone. Second, by a semicircular sulcus 
(the jugular groove}, which in articulation with the 
occipital bone forms the jugular foramen. Third, by 
a small notch for the reception of the ninth, tenth, 
and eleventh cranial nerves. Fourth, by an irregu- 
larly serrate border for articulation with the basilar 
process of the occipital bone, and by a small surface 
at its inner extremity with the body of the sphenoid 
bone.-The following parts are seen on the inferior 
free surface: First, a smooth space lying between the 
preceding and the inferior orifice of the carotid canal. 
Second, the floor of the carotid canal. To the outer 
side of the inferior surface is seen the large circular 
orifice of the canal, and to its inner side (the bone 
being in articulation), the median lacerated foramen. 
Near the basilar process of the occipital bone it is 124 
THE BONES. 
roughened for the attachment of the pharyngeal 
aponeurosis; anteriorly it is smooth for the reception 
of the cartilaginous portion of the Eustachian tube. 
The tympanic portion of the bone lies wholly upon 
its under surface. It is of an irregular shape, and 
composed entirely of compact tissue. When studied 
from without it presents a U-shaped portion wedged 
between the mastoid and the post-glenoid processes, 
limiting three sides of the large opening leading to 
the external auditory meatus, and thence to the tym- 
panic membrane. The fourth and upper side of the 
meatus is formed by the squama. The curve of the 
U is much roughened, and produced downward. The 
tympanic division extends inward, and is seen on the 
base of the skull as a narrow compressed lamina, 
which insheathes the base of the styloid portion. 
Hence this aspect is called the vaginal process, which 
may be said to limit the glenoid region posteriorly. 
It is concave for the reception of the post-mandibular 
portion of the parotid gland. It terminates some- 
what abruptly in a point opposed to the spinous pro- 
cess of the sphenoid bone at the beginning of the 
sulcus for the cartilaginous portion of the Eustachian 
tube. In narrow long skulls this point is often pro- 
duced downwards as a spine. The floor of the external 
auditory meatus answers pretty nearly to the level of 
the base of the skull. 
The styloid portion is composed of two separate 
pieces-the styloid and the tympano-hyal. The sty- 
loid is an elongated cylindroid spine, having an 
average length of an inch, and arises directly behind 
the vaginal process. It gives origin to the styloid 
group of muscles and to the stylo-hyoid ligament. 
The tympano-hyal is an unimportant ossicle placed 
between the base of the styloid and the stylo-mastoid 
foramen. - The styloid process may attain great 
length, when it will complicate a dissection for re- 
moval of tumors of the side of the neck. 
The mastoid portion, seen from without, lies between 
the supra-mastoid ridge and the masto-occipital and 
masto-parietal borders. It is composed of spongy 
and compact tissue, and is derived from an extension 
outward of the primordial petrous portion joined with 
an outward extension of the squama. It is divided 
into a mastoid and a post-mastoid region by the late- 
ral extension of the superior semicircular line of the 
occipital bone. The region, in great part, pertains to 
the occiput, with the curves of which it is continuous. 
Laterally, the mastoid region presents a large nipple- 
shaped process, the mastoid process, for the origin of 
the Sterno-Cleido-Mastoid and the Splenitis Capitis 
muscles. In the majority of skulls an irregular de- 
pression is seen extending along the outer surface of 
the process. This marks the position of the primor- 
dial squamoso-petrosal suture. Behind the mastoid 
process lies the digastric fossa, for the origin of the 
Digastric muscle. Extending parallel with its outer 
side is the groove for the occipital artery. Above the 
mastoid process lies the mastoid, foramen for the trans- 
mittal of a vein inwards to join the lateral sinus. 
Medianly the mastoid division lies behind the pe- 
trous portion, and is marked with a deep broad sulcus 
for the lateral sinus. The union of the squamoso- 
parietal and masto-parictal borders exhibits a well- 
marked retiring angle for the posterior inferior angle 
of the parietal bone. 
Development.- The temporal bone arises both 
from membrane and from cartilage: the squamous and 
tympanic portions from the former; the petrous por- 
tion and styloid process from the latter. Ossification 
is first announced in the squama as early as the third 
month. Shortly after this the process begins in the 
tympanic portion. Some obscurity exists respecting 
the development of the petrous portion, which usually 
is stated to arise at about the fifth or the sixth month 
from a number of minute granules; but from what is 
seen in lower animals there appear to be three sepa- 
rate ossicles in the bony envelope to the labyrinth. 
It is probable that in man more than three definite 
centres exist, but that they early coalesce. At birth 
i the temporal bone is nearly complete, the several 
portions having united, but the mastoid process has 
i not appeared, the styloid is yet cartilaginous, and 
the auditory meatus is shallow, since the tympanic 
portion is as yet a mere rim of bone. 
Remarks.-The temporal bone is the seat of many 
pathological conditions, to appreciate which an exact 
knowledge of anatomy is required. M. Chassaignac1 
describes a case in which the right condyle of the 
lower jaw was driven into the skull by a fall from a 
great height upon the chin. The right condyle was 
found in the autopsy pressing against the middle lobe 
of the brain, in which was a large abscess.-Fracture 
of the vaginal process may ensue upon the lower jaw 
being driven directly backward.-But by far the 
greatest importance is to be attached to the complica- 
tions arising from aural disease. Mr. Toynbee2 has 
said: "Each of the cavities of the ear has its par- 
ticular division of the encephalon to which it com- 
1 Plaies de Tete, 158. 
2 Med.-Chir. Trans., xxiv. THE BONES OF THE HEAD. 
125 
municates disease." A secondary inflammation may 
extend from the roof of the tympanic cavity to the 
cerebrum; from the external meatus and mastoid 
cells to the lateral sinus and cerebellum; and from the 
labyrinth to the medulla and the base of the brain. 
Of these the second is the most frequently seen. The 
masto'd cells lie in such close juxtaposition to the 
lateral sinus, that between the ages of eighteen and 
forty-five the septum is thin, and may in parts be 
absent, so that the lateral sinus touches directly the 
mucous lining of the cells. In such cases, an inflamma- 
tory process may extend from the mastoid cells to the 
lateral sinus, and encranial phlebitis and death may 
ensue. As a rule, however, inspissation of the mucus 
of the mastoid cells, if not suppuration and caries, 
precedes the meningeal complication.-The mastoid 
foramen has been known to discharge pus from a 
deep-seated abscess, as seen in the interesting case 
reported by Dr. F. Buszard.1 The patient bad suf- 
fered eleven months. During the latter portion of 
this term drowsiness and vomiting were noticeable 
symptoms. The bone was trephined over the position 
of the foramen, when the escape of viscid pus, which 
was believed to have formed within the cranium, 
followed. The patient recovered.-The petrous, the 
squamous, and even the tympanic portions of the 
temporal bone are occasionally lost by necrosis. Mr. 
Hinton2 reports an instance of the exfoliation of the 
right tympanic bone in the course of an attack of 
ostitis following scarlatina in a child five years old. 
P. Hewitt3 reports a remarkable instance in which 
the entire bone died and was removed, with a fatal 
result. The case was that of a boy eleven years of 
age, the subject of chronic ear discharge. At the 
autopsy the auditory and facial nerves were seen to 
terminate in a bulbous mass on the dura mater. The 
internal carotid artery above and below could be 
traced as far as the walls of the cavity which had 
lodged the bone. The vessel was reduced to a small 
size, however, before it reached this spot, and was 
impervious. 
While the temporal bone is not very vascular, as 
the frequency and extraordinary extent of necrosis 
above mentioned would indicate, severe and even 
fatal hemorrhage has attended the removal of bony 
sequestra (see account of Common Carotid Artery). 
Meningitis and inflammation of veins joining the 
lateral sinuses may also succeed necrosis of this bone. 
The mastoid process, according to Portal.1 is at 
times the seat of large syphilitic exostoses. 
The space behind the ear in the living subject is 
sometimes called the mastoid fossa in clinical reports. 
It, however, lies for the most part above the mastoid 
process, and answers to the squamous surface. The 
term post-auricular space is here more appropriate. 
This space, together with the squama, and the por- 
tions defining the external meatus, are the only parts 
of the temporal bone that can be detected in the un- 
dissected subject. 
THE SPHENOID BONE. 
The sphenoid bone (figs. 1 and 2, Plate XVII., 
Plate XXIV.) occupies a central position in the head. 
Before it lies the face; behind it the temporal bone 
and the basilar process of the occipital. At the sides 
it joins the parietal and frontal bones, as well as the 
squamous portion of the temporal bone. It enters 
into the construction of the roof of the pharynx and 
nasal chambers, affords attachment to three of the 
four masticatory muscles, supports the superior dental 
arch posteriorly, forms part of the outer wall of the 
orbit, and the anterior and middle cerebral fossae. It 
is perforated by foramina for branches of the fifth pair 
of nerves, the optic nerve, and the meningeal arteries. 
The sphenoid bone is divided into a body and 
three pairs of processes, named as follows: the lesser 
wings, projecting outward from the side of the body 
anteriorly; the greater wings, from the side of the 
body posteriorly, and the pterygoid processes, project- 
ing downward from the sides of the body beneath. 
The body of the bone is of a quadrilateral figure, 
and presents for examination six surfaces, the superior, 
inferior, anterior, posterior, and two lateral surfaces.- 
The superior surface lies entirely within the brain- 
case. It is marked in front by the ethmoid spine; be- 
hind this by a smooth surface which is but faintly 
marked by a median elevation continuous with the 
crista galli of the ethmoid bone. On either side lies 
a groove for the olfactory tract. Connecting these 
grooves is a nearly transverse sulcus-the optic groove 
-to accommodate the optic nerves. Directly behind 
this groove is the olivary process for the support of 
the optic chiasm. The remainder of the surface is 
deeply concave, and forms the pituitary fossa (sella 
turcica) for the reception of the pituitary body. Lim- 
iting this fossa posteriorly is an oblique plate of bone, 
directed downward and backward, called the dorsum 
sellce (clivus). When the sphenoid bone is in articu- 
1 Brit. Med. Journ., 1871, 88. 
2 Trans. Path. Soo., London, 18G6, 274. 
3 Med. Times and Gazette, 1864, i. 205. 
1 Anat. Medical. 126 
THE BONES. 
lation with the occipital, the dorsum sellm is seen to 
be continuous with the upper surface of the basilar 
process, and aids in supporting the pons Varolii. The 
dorsum sellae is composed of loose spongy tissue, and 
ends anteriorly by a free border, the outer angles of 
which are called the posterior clinoid processes.-The 
inferior surface is continuous with the anterior, pre- 
senting in relation to it no well-defined boundary. 
Conspicuous upon the surface is a triangular spine- 
the rostrum-which in articulation with the vomer 
fits into its upper groove. On each side is a narrow 
depression, covered in part by a transverse lamina-the 
vaginal process-derived apparently from the base of 
the pterygoid process to articulate with the alae of the 
vomer.-ry\\a anterior (nasal) surface presents a continu- 
ation of the rostrum which here articulates with the 
perpendicular plate of the ethmoid bone. On each side 
of this median projection lies a sphenoidal turbinated 
bone. Each sphenoidal turbinated bone is defective 
in its upper-part. It is of a triangular figure, its apex 
pointing downward and backward. It is a distinct 
bone in the infant, but soon unites with the ethmoid 
bone in front and the sphenoid behind. With its fel- 
low of the opposite side it largely contributes to the 
formation of the sphenoidal sinus. Inferiorly the parts 
on each side of the rostrum are in part concealed by 
the apices of the sphenoidal-turbinates.-The posterior 
surface is of a quadrangular figure, which in the young 
subject is covered with cartilage. It articulates with 
the basilar process of the occipital bone. At the sides 
a minute process is seen which aids in forming the 
groove for the superior petrosal sinus.-The lateralsur- 
facescA the body are almost entirely within the brain- 
case, a small portion only extending forward to termi- 
nate at the corresponding surfaces of the sphenoidal tur- 
binates. Each surface presents a conspicuous depres- 
sion for the internal carotid artery (sigmoid groove). It 
is better defined posteriorly than anteriorly, and along 
its lateral than median border. Two minute processes 
are detected along the course of the groove; the first 
and larger at the lateral border of the beginning of 
the groove called the sphenoidal tongue, and the second 
at the median border of the anterior end, called the 
middle clinoid process.-The body of the bone thus de- 
fined is hollow in the adult to form the sphenoidal 
sinus. This sinus is so often divided by a vertical 
septum into two that the term sphenoidal sinuses would 
be more appropriate. Clinical writers, however, inva- 
riably speak of it as a single chamber. The sphenoidal 
sinus communicates with the posterior ethmoidal cells, 
but commonly opens upon the nasal fossae. 
The greater wing of the sphenoid bone springs from 
the base and the hinder portion of the lateral sur- 
face. It consists almost entirely of spongy tissue. It 
arises by a massive base at the inferior border of the 
body of the bone, slightly in advance of the begin- 
ning of the carotid groove and behind the sphenoidal 
fissure. It is divided conveniently into a horizontal 
and an ascending portion.-The horizontal portion is 
smaller than the ascending. Its upper surface is 
marked at its outer half by a thick oblique irregular 
surface for articulation with the squamous portion of 
the temporal bone. The posterior border presents 
a compressed thin edge, which is slightly concave 
below, and forms when the bone is articulated a 
sulcus for the cartilaginous portion of the Eustachian 
tube. The under surface is smooth, and bounded ex- 
ternally by the zygomatic crest. Posteriorly the under 
surface terminates in a sharp process, directed down- 
wards, termed the spinous process. To it is attached 
the internal lateral ligament of the lower jaw.-The 
ascending portion passes outward and slightly forward, 
and upward, to be received anteriorly by the frontal 
bone through a broad triangular, irregular surface at 
the outer side of its orbital plate, and the anterior 
inferior angle of the parietal bone. Posteriorly it is 
received by the squamous portion of the temporal 
bone. It is concave within to receive the middle 
lobe of the cerebrum. It is slightly concave without, 
where it is marked by two muscular impressions, one 
above the pterygoid ridge for the Temporal muscle, 
and the other below the ridge for the origin of the 
outer head of the External Pterygoid muscle. The 
process is smooth in front to form the orbital surface, 
and enters into the outer wall of the orbit. The or- 
bital surface is of a quadrangular figure. It is notched 
at its inner surface for the passage of a branch of the 
ophthalmic artery. It is compact where it bounds 
the sphenoidal tissues inferiorly ; made up of spongy 
tissue in the centre, it is again thin and compact 
EXPLANATION OF PLATE XVII. 
Fig. 1. The sphenoid bone seen from in front. 
Fig. 2. The sphenoid bone seen obliquely from above. 
Fig. 3. The sphenoid bone seen from behind. PLATE XVil 
Fie.l 
Fig . 2 
■3 
T. Sinclair k THE BONES OF THE HEAD. 
127 
where it joins the malar bone to form the spheno- 
temporal partition. Between the pterygoid impres- 
sion and the orbital plate a well-defined groove is seen 
leading to the spheno-maxillary surface. 
The lesser wing, composed of compact tissue, arises 
from the junction of the side with the upper surfaces 
of the sphenoid bone. It passes horizontally outward, 
and tapers as it approaches the greater wing to which 
at the fronto-sphenoid junction it may be attached. It 
possesses two pedicles. The anterior is thin, and lies 
on the same plane with the orbital part of the frontal 
bone. The posterior is stout and rounded, and is con- 
tinuous with the outer edge of the olivary process 
medianly, and with the under thickened free border of 
the lesser wing laterally. The anterior border of the 
lesser wing is thin and serrate to articulate with the 
frontal bone. The posterior border is thickened and 
free. Its median extremity projects inward to form 
the anterior clinoid process. This process presents a 
median border grooved for the ophthalmic artery, and 
a shelving external border which overhangs the sphe- 
noidal fissure. The opening between the anterior and 
posterior pedicles is the optic foramen, which trans- 
mits the optic nerve and the ophthalmic artery. The 
posterior pedicle separates the optic foramen from the 
sphenoidal fissure. The anterior surface of the lesser 
wing as it lies behind the cribriform plate of its own 
side sends forward a small process of bone, which aids 
in covering in the posterior ethmoidal cells.1 
The pterygoid processes of each side descend from 
the junction of the body with the greater wing. 
Anteriorly the process forms at its upper third a 
smooth triangular surface, which forms the posterior 
wall of the spheno-maxillary fossa. The remaining 
portion of the process is in articulation with the pa- 
latal bone. Posteriorly the process is free along its 
entire border.-The pterygoid process is in great 
part divided into an inner and outer plate. The space 
between these plates, best seen from in front, is called 
the pterygoid notch, which is occupied in the skull by 
the pyramidal process of the palatal bone. The space 
between the plates seen from behind is called the 
pterygoid fossa, and gives origin to the Internal Ptery- 
goid muscle. The outer pterygoid plate is broader 
than the inner, and is directly continuous with the 
outer wing. It is deflected slightly outward and for- 
ward to articulate with the palatal bone above the 
dental alveoli. The lower head of the External 
Pterygoid muscle arises from its outer surface. The 
inner plate is a compressed vertical layer of bone ar- 
ticulating in front with the palatal bone. The inner 
plate is free behind. Its inferior portion is prolonged 
as a hook-like extension, forming the hamular process, 
qnqt which plays the tendon of the Tensor Palati 
muscle. The pterygoid fossa as it terminates supe- 
riorly is continuous with a small elliptical depression, 
which has received the name of the scaphoid fossa. It 
gives origin to the Tensor Palati muscle. 
The Foramina of the Sphenoid Bone.-The foramina 
of the great wing are as follows: First, the round 
foramen, seen at the anterior third of the side of the 
body and directed forward. It transmits the superior 
maxillary branch of the fifth pair of nerves. Second, 
the oval foramen. This is a large opening in the hori- 
zontal portion of the greater wing near its petrosal 
border, behind and to the outer side of the round 
foramen. It is directed downward, and transmits 
from above the inferior maxillary branch of the fifth 
pair, and from below the lesser meningeal artery. 
Third, the spinous foramen, which transmits the great 
meningeal artery. The pterygoid process exhibits a 
canal at its base directed horizontally forward, which, 
transmitting as it does the great petrosal or Vidian 
nerve, has received the name of the Vidian canal. 
The internal pterygoid plate is marked at its base in- 
ternally by a minute opening which, when the bone 
is articulated with the palatal, is converted into a 
canal known as the pterygopalatine canal for the 
artery and nerve of the same name. 
The space between the greater and lesser wings is 
of an irregular form, broader at the body of the bone 
than at the outer end, where it is narrowed to a mere 
chink. This space in the separate bone has received 
the name of the sphenoidal fissure, and in the skull 
the anterior lacerated foramen. It transmits the third, 
fourth, and sixth nerves, the ophthalmic branch of 
the fifth nerve, and the ophthalmic vein. 
Structure.-The structure of the sphenoid bone, 
as already mentioned, is for the most part spongy. 
The greater wing with the exception of the horizontal 
plate is composed of thick vascular spongy tissue. In 
skulls that have been much weathered this tissue be- 
comes exposed, and may be eroded to a great extent. 
The pterygoid process at its base, and including in 
great part the inner plate, is also spongy. The lesser 
wings are compact. 
Development.-The sphenoid bone develops from 
thirteen to fifteen centres of ossification, viz., one for 
each greater wing, inclusive of the external pterygoid 
1 For special description of this process in man and fox, see 
Luschka, Zeit. fiir Wissenschaft. Zool. viii., 1857, 123, Taf. iii. 128 
THE BONES. 
process; two for the posterior portion of the body, or 
the basi-sphenoid ; one for the anterior portion of the 
body, or the pre-sphenoid (this is occasionally absent); 
one for each of the lesser wings (these extend into and 
occupy the cartilage of the pre-sphenoid in the event 
of no separate centre arising therein); one for each 
of the internal pterygoid plates; one for each of the 
sphenoidal turbinate (three separate ossicles may be 
detected here); and one for each of the sphenoidal 
tongues. 
The order in which these several centres appear is 
as follows: The centre for the greater wings, which 
appears at about the second month; the centres for 
the basi-sphenoid, nearly the same time; the centre 
for the pre-sphenoid, at about the ninth week, includ- 
ing those for the lesser wings; the centres for the 
internal pterygoid {dates and the sphenoidal tongues, 
at the fourth month; the centres for the sphenoidal 
turbinates, at about puberty. 
At birth the sphenoid bone is composed of three 
pieces-the two greater wings with the internal 
pterygoid plates, and the two lesser wings with the 
body. The greater wings join the body at the end of 
the first year. The sutural line of union between the 
pre-sphenoid and basi-sphenoid is seen as late as the 
third or fourth year; the turbinates join the pre- 
sphenoid, and the basi-sphenoid joins the occipital at 
puberty. 
Remarks.-The greater wing of the sphenoid bone 
is often the seat of inflammation in strumous and 
syphilitic subjects. In most specimens of the sphe- 
noid bone of the adult this portion is seen conspicu- 
ously marked with vascular foramina. The region of 
the pituitary fossa is occasionally the point of origin 
of diseased action-either within the body of the bone 
or within the pituitary body-which may extend 
laterally and involve the cavernous sinuses,1 and the 
internal carotid arteries. Instances have been re- 
corded of caries of the body eroding one of the last- 
named vessels and causing fatal hemorrhage. 
Robert1 mentions an instance of fracture of the body 
of the sphenoid bone at the sella turcica, the dura 
mater in contact with it being torn; The crevice thus 
formed had communicated directly with the roof of 
the pharynx during life, and the sub-arachnoid fluid 
had trickled through the opening into the nose, creat- 
ing a watery discharge. 
For additional remarks see Base of Skull. 
THE PARIETAL BONE. 
The parietal bone (Plate XVIII.) is of a quadri- 
lateral figure, and is situated on the side of the cranial 
vault between the fellow of the opposite side, the squa- 
mous and the mastoid portions of the temporal and 
the great wing of the sphenoid bone below, the frontal 
bone in front, and the occipital bone behind. 
The anterior superior angle is a right angle. It is 
developed in infancy to aid in closing the great fonta- 
nelle. The postero-superior angle is an obtuse angle, 
and assists in closing the postero-superior fontanelle. 
The a ntero-inferior angle is in the isolated bone the 
most produced of any. It forms a narrowed tongue 
of bone fitting in the space between the frontal and 
temporal bones, and articulates with the sphenoid 
bone. The postero-inferior angle is broader and more 
truncated than the others. It joins the mastoid por- 
tion of the temporal bone. 
The parietal bone is composed of one or more layers 
of spongy tissue, placed between two plates of compact 
tissue, of which the outer is the most variable. The 
bone presents for examination two surfaces and four 
borders and angles The bone is marked externally by 
a conspicuous rounded elevation, termed the parietal 
eminence-which corresponds to the centre of ossifi- 
cation. At the lower part of the external surface is 
seen a semicircular canal, limiting the temporal fossa 
superiorly. The bone is concave, and is deeply grooved 
by the great meningeal artery, which is directed from 
below upward and before backward from the antero- 
inferior angle. Near the upper margin of the bone 
1 W. Moxon. Tr. Clin. Soc. Lond., v. 45. 
' Gazette des Hopiteaux, 1840, 205. 
EXPLANATION OF PLATE XVIII. 
Fig. 1. The parietal bone seen from without. 
For the words " with frontal bone" on left hand border 
read " with occipital bone." 
Fig. 2. The parietal bone seen from within. PLATE XVlII 
Figi 
Fig. 2 
T. Sinclair & Sort Lith. THE BONES OF THE HEAD. 
129 
are seen several shallow depressions for the Pacchio- 
nian bodies. Inferiorly and posteriorly the inner sur- 
face is grooved for the transverse sinus. The upper, 
anterior, and posterior borders are simple in character, 
and present coarse serrations for articulation with 
adjacent bones. The inferior border is bevelled at its 
anterior two-thirds for articulation with the squama 
-the posterior third being coarsely serrated, to articu- 
late with the mastoid division of the temporal. 
Development.-The parietal bone arises from a 
membranous matrix by a single centre of ossification 
which appears at the seventh or eighth week. 
Remarks.-This bone will occasionally exhibit be- 
tween the parietal eminence and the borders of the 
bone one or more foramina of large size. They are 
evidences of defective development of the part, which 
process would appear to be less active in the region 
between the centre of ossification and the borders of 
the bone than elsewhere. Dr. J. S. Parry1 has asso- 
ciated the tendency to such a condition with rickets. 
Prof. Turner2 believes these openings to be enlarged 
vascular foramina, for although they are occupied 
with membrane during life, such membrane was found 
by him to be perforated by minute vessels. 
THE FRONTAL BONE. 
The frontal bone (figs. 1, 2, and 3, Plate XIX.) is a 
symmetrical bone situated at the anterior part of the 
cranium between the parietals above, the wings of 
the sphenoid behind, and the bones of the face below. 
It is for the most part composed of compact tissue. 
The bone supports the anterior half of the cerebrum 
within; it affords attachment to the part of the Tem- 
poral muscle at its sides, where it enters into the com- 
position of the temporal fossa. It forms the roofs of 
the orbits, and receives the cribriform plate of the 
ethmoid bone. 
The frontal bone is divided into an ascending 
and a horizontal portion. The ascending portion is 
marked anteriorly by the upper margins of the or- 
bits-the supra-orbital arches. At the inner third of 
each arch is seen the supra-orbital notch, for the escape 
of the frontal branch of the ophthalmic nerve. This 
is sometimes converted into a foramen. The outer 
extremity of the arch is continuous with the external 
angular process; the inner extremity-more produced 
-forms the internal angular process. Between the 
two internal processes lies a rounded elevation-the 
nasal eminence, which forms the anterior wall of the 
frontal sinus. 
The frontal sinus (fig. 1, Plate XXIII., figs. 1 and 2, 
Plate XXIV.) is an irregular chamber, lined with 
mucous membrane, situated between the inner and 
outer plates, at the junction of the ascending and 
horizontal portions. It communicates with the nasal 
chamber by means of the infundibulum of the ethmoid 
bone. The inferior surface is irregularly serrate for 
articulation with the ascending process of the superior 
maxillae, the nasal bones, and the vertical plate of 
the ethmoid. A conspicuous median process of the 
frontal bone-the nasal spine-is firmly wedged be- 
tween these bones. Extending from the base of the 
process upward along the median line are seen the 
remains of the frontal suture. Upon either side of 
the frontal suture is the circular frontal eminence, and 
below each eminence the supra-ciliary ridge, which 
corresponds pretty nearly with the supra-orbital arch 
of its own side. Laterally the ascending portion is 
marked by a muscular impression, called the temporal 
ridge, which limits the anterior third or fourth of the 
temporal fossa. Between this ridge and the supra- 
orbital arch is produced the external angular process, 
a conspicuous mass of spongy tissue articulating 
with the malar bone and the greater wing of the 
sphenoid bone. The posterior, or encranial surface, 
is smooth for the reception of the anterior lobes of 
the cerebrum. In the middle line is seen a deep 
narrow sulcus, narrower below than above, for the 
great longitudinal sinus. Inferiorly in front of the 
ethmoidal notch the sulcus ends in a minute opening, 
the so-called foramen ceecum. This opening is con- 
tinuous in childhood with the nasal chambers, and 
transmits a small vein. In the adult it is closed, and 
is occupied by fibrous tissue. 
The horizontal portion is composed of the two orbi- 
tal plates and the ethmoidal notch. The orbital plates 
are two thin laminae, which, as already said, form the 
roofs-of the orbits without and the floor of the anterior 
cerebral fossa in the main within. The orbital surface 
is smooth save at the anterior portion of the median 
half, where it is marked by a minute process for the 
tendon of the Superior Oblique muscle. Behind the 
external angular process the orbital plate accommo- 
dates the lachrymal gland. The encranial surface is 
more uneven than the orbital, and slopes gently 
toward the ethmoidal notch. Each plate is marked 
by two or three irregular elevations forming several 
shallow depressions, which, from the fancied resem- 
blance they are thought to bear to the impressions 
1 Amer. Journ. Med. Sci., Jan. 1872, 43. 
2 Edinburgh Royal Soc. Proc., v. 1877, 444. 130 
TTIE BONES 
made by finger-tips upon some yielding substance, 
have received the name of the digital depressions. 
The ethmoidal notch is designed for the reception 
of the cribriform plate of the ethmoid bone. Its sides 
exhibit numerous irregular cell-like depressions, which 
assist when the bone is in articulation to form the eth- 
moidal cells. 
Development.-The frontal bone arises from mem- 
brane by two centres of development, one on either 
side of the median line. These centres appear near 
the orbital arches at the seventh week. The bone 
is composed of two pieces at birth. The suture be- 
tween the right and left halves is called the frontal 
suture, and is in the line of the interparietal or sagit- 
tal suture. It is commonly obliterated at about the 
third year. The occasional persistence of this serrate 
suture is a subject of more than passing interest. 
Surgeons have been known to confound such a suture 
with a line of fracture.1-Authorities vary with re- 
spect to the time of development of the frontal sinus. 
Albinus described the sinus as existing in the foetus of 
nine months. Blumenbach2 and Henle believe it to 
be formed at the end of the second year. Its devel- 
opment would appear to be variable, and to be re- 
tarded by some diseases, among which may be men- 
tioned rickets, scrofula, and hydrocephalus. 
Development of the bone may be varied by the 
appearance of accessory centres upon the orbital plates. 
These frequently remain separate from the rest of the 
bone, resembling in their independent position the 
Wormian bones. Joh. Czermak3 has described six 
cases of such abnormally constituted orbital plates. 
Remarks.-From want of proper union of the 
halves of the frontal bone hernia cerebri has been 
known to occur at the frontal suture.-Mr. Shaw ex- 
hibited before the Pathological Society of London an 
encephalocele removed from the head of an infant. 
The mass had projected through an opening in the 
frontal bone at the root of the nose, between the 
sutures uniting the frontal, ethmoid, and nasal bones.1 
-The frontal bone will yield occasionally small ex- 
ostoses. These are sometimes of extraordinary com- 
pactness, and involve the median portion, as well as 
the orbital plates.- The frontal bone is infrequently 
fractured where it is most convex, as at the frontal 
and nasal eminences. It is relatively often fractured 
at the sides where the bone enters into the composition 
of the temporal fossaa, notwithstanding that in such 
locality the bone is protected by the Temporal muscle 
and aponeurosis.-The external angular process of 
the frontal bone frequently presents upon its orbital 
aspect, and thence to the roof of the orbit, a patch of 
foramina. In the same locality a cribriform exostosis 
has been occasionally observed. 
The outer (anterior) wall of the frontal sinus has 
been removed for the extraction of polypi growing 
from the mucous membrane lining the sinus.2 In 
a case mentioned by Jno. Bell,3 the polypous tumors 
pressed the inner wall of each orbit outward, while 
the posterior wall was pressed backward. 
Owing to the continuity of the frontal sinus with 
the nasal chamber larvae of insects can readily pass 
from the latter to the former. Numerous cases of 
this condition have been observed, chiefly in tropical 
countries. 
The size of the frontal sinus is subject to great va- 
riation. Usually confined to the frontal eminence or 
the space continuous thence with the supraorbital 
arches, it may extend over the entire length of supra- 
orbital arches. It is apt to increase in size with 
advancing years. Under the influence of diseased 
action the frontal sinus may be obliterated, as in 
syphilis. One half of the sinus is apt to be larger 
than the other. Bichet candidly mentions an expe- 
1 Velpeau, Anat. Chirurg., 228. 
2 History and Diseases of Bones, etc., Gottingen, 1786, 101. 
3 Zeitsclir. fur Wissenscliaft. Zool., iii. 27, pl. 2. 
1 Trans. Path. Soc. of Lond., 1858, 2. 
2 Lancet, 1859, ii. p. 634. 
3 Principles of Surgery, iii. p. 134. 
EXPLANATION OF PLATE XIX. 
Fig. 1. The frontal bone seen from the side. 
Fig. 2. The frontal bone seen from beneath. 
A leader should be drawn from the words "with Sup. 
Maxilla" to the surface directly behind the one for articula- 
tion with the nasal bones. 
Fig. 3. The frontal bone seen from in front. 
Fig. 4. The ethmoid bone seen from beneath. 
For " Unciform Process" read " Uncinate Process." PLATE XIX 
Fig. 4 
Fig. 2 
Figi 
rig.3 
1'. Sinclair & Son. Lath THE BONES OF THE HEAD. 
131 
rience of his own in which he for a time mistook such 
an asymmetrical growth for an exostosis. 
From the extreme thinness of the orbital plates a 
slight direct blow will break them. This has actually 
occurred in more than one instance. Inconsiderable 
and sometimes undetected external wounds, from such 
objects as tobacco-pipe stems, and tips of umbrella 
sticks, have been associated with fracture of the orbi- 
tal plate and cerebral injury.1 
Abscess of the frontal sinus will expand the walls 
and cause outward inclination of the inner aspect of 
the orbit above the os planum of the ethmoid. A 
patient under the care of Mr. Soelberg Wells,2 showing 
these peculiarities, had, in consequence of periocular 
infiltration as well as from the direct pressure of the 
abscess, protrusion of the right eyeball. 
THE ETHMOID BONE. 
The ethmoid bone (fig. 4, Plate XIX.; fig. 1, Plate 
XX.)-while properly a cranial bone, inasmuch as it 
enters into the construction of the brain-case-lies for 
the most part within the region of the face. Like 
the sphenoid bone, it is strictly symmetrical; and 
is composed of a median portion which receives the 
name of the vertical plate, and two lateral portions or 
masses. Uniting the vertical plate and the lateral 
masses is the horizontal or cribriform plate. The entire 
bone is of a cuboidal figure, and aids in defining the 
floor of the anterior cerebral fossa, the nasal cham- 
bers, and the inner wall of each orbit. The nasal 
surfaces of the ethmoid are covered with mucous 
membrane that accommodates the organ of smelling. 
The vertical plate (meso-ethmoid) is a thin lamina 
of bone in the median line extending downward from 
the cribriform plate into the face, and upward from 
the cribriform plate into the brain-case. The down- 
ward extension is vastly the larger of the two, and 
has received the name of the perpendicular plate of 
the ethmoid bone. It constitutes the upper third of 
the nasal septum. Its anterior boundary is inclined 
forward, and articulates with the nasal spine of the 
frontal and the crest of the nasal bones. The poste- 
rior border joins the sphenoidal crest of the sphenoid 
bone. The inferior border is obscurely angulated: 
the portion sloping upward and forward in front of 
the angle articulates with the triangular cartilage of 
the nose, while the portion back of the angle articu- 
lates with the vomer. The sides of the vertical plate 
are grooved for the olfactory nerves. 
The upward extension of the vertical plate forms 
a robust angulated ridge, ivory-like in appearance, 
which has been named, from its assumed resemblance 
to the cock's comb, the crista galli. Seen from the 
cranial surface, the crista galli appears to arise from 
the horizontal plate. Its anterior border is nearly 
vertical, and is provided at its base with two sym- 
metrical flanges-the so-called ethmoidal wings or 
alee. The great longitudinal fold of the dura mater 
is attached to the crista galli. 
Each lateral mass (ethmo-turbinate bone) is of a 
cuboidal figure, and presents, therefore, six surfaces 
for examination. Of these, the superior and inferior 
are imperfectly defined; the former being composed 
of irregular cellules that are covered in and com- 
pleted by the frontal bone; the latter, being part of 
the complicated median surface, can be described in 
connection therewith. 
The median or nasal surface (fig. 2, Plate XXIV.) 
is of great complexity. It is defined by a lamella that 
arises from the cribriform plate and descends at its 
anterior third to the inferior border without interrup- 
tion. At its origin anteriorly it is continuous with 
the pedicle of the uncinate process, and posteriorly 
with the spheno-turbinated bones. At its posterior 
two-thirds, the nasal surface is interrupted by a large 
horizontal sulcus, called, from its relations to the to- 
pography of the nasal chamber, the superior meatus. 
It is continuous with the posterior border of the bone 
which it deeply notches. All that portion of the bone 
lying between the cribriform plate and the upper mar- 
gin of the sulcus is called the superior turbinated bone, 
and all that portion between the lower border of the 
sulcus and the lower margin of the nasal surface is 
called the middle turbinated bone. The middle turbi- 
nated bone is scrolled outward, and constitutes the 
most conspicuous feature on the under surface of the 
bone. Directly to the outer side of the middle turbi- 
nate lies the large sulcus, known, when the ethmoid 
is articulated with its associate bones, as the middle 
meatus. The entire median surface of the ethmoid 
is minutely roughened and pitted by the delicate canals 
and openings of exit of the olfactory nerves. 
Arising in common with the anterior margin of 
the median surface, to which it may be regarded as 
an appendage, is the uncinate process or process of 
Blumenbach. This is an irregular lamina extending 
downward, outward, and backward-lying at first to 
the median side of the ascending process of the supe- 
rior maxilla, and then to the median side of the lach- 
rymal. The uncinate process articulates with the 
ethmoidal process of the inferior turbinated bone, 
1 Dublin Journ. of Med. Sci., xi. p. 353. 
2 Lancet, 1870, p. 694. 132 
THE BONES. 
and aids in closing the orifice of the maxillary 
sinus. 
The lateral or outer surface of the lateral mass is 
nearly smooth. Its anterior portion is cellular, and 
is covered in by the lachrymal; the remaining por- 
tion forms the median wall of the orbit, and, from its 
uniformly smooth appearance, has received the name 
of the os planum (fig. 1, Plate XXIV.). Two grooves 
at the upper margin of the os planum transmit eth- 
moidal branches of the ophthalmic nerve. The thin 
posterior surface joins the sphenoid.-The space be- 
tween the median and lateral surfaces of the lateral 
mass is occupied by the superior meatus and a 
number of open spaces lined with mucous membrane 
which have received the name of the ethmoid cells. 
Two sets of these cells are described, viz., the anterior 
and the posterior. The posterior set of cells opens 
upon the superior meatus, while the anterior cells 
are continuous with the frontal sinus by means of a 
passage known as the infundibulum. Inferiorly, the 
anterior cells communicate with the middle meatus. 
The cribriform plate or lamella (fig. 1, Plate XXIII.) 
unites the cranial surfaces of the lateral masses and 
the vertical plate. Strictly speaking, there are two 
cribriform plates, one on each side of the crista galli. 
Each plate receives the olfactory bulb of its own side 
-hence it is sometimes called the olfactory sulcus- 
and transmits the olfactory nerves arising from its 
under surface. The numerous openings of the cribri- 
form plate are arranged without apparent order. They 
are for the most part the orifices of obliquely-placed 
short canals. Directly behind the ethmoidal wing 
lies a narrow slit-like opening for the nasal branch of 
the ophthalmic nerve. 
Structure.-The ethmoid bone is composed of 
delicate lamellae of varying degrees of thickness. 
The thickest portions of the bone are the crista galli 
-which is occasionally hollow-the wings, and the 
pedicle of the uncinate process. 
Articulation.-The ethmoid bone articulates by 
the perpendicular plate with the vomer; the lateral 
masses with the frontal, sphenoid, nasal, lachrymal, 
superior maxillary, and palatal bones, and by the un- 
cinate process with the inferior turbinated bone. 
Development.-The ethmoid bone arises from 
three centres of ossification, one for each lateral mass, 
and one for the vertical plate. The orbital plates 
begin to ossify in the fourth or fifth month ; the 
vertical plate and the cribriform plate within the first 
year. The bone is complete at the fourth or fifth year. 
Remarks.-For detailed clinical application of the 
anatomy of the ethmoid bone, see Nose. The cribri- 
form plate can be readily fractured by instruments 
thrust upward from within the nasal chamber, and 
the brain thus penetrated. After such a method in- 
fanticide has been committed. It is asserted that the 
ancient Egyptians removed the brains of their dead 
through such an opening prior to subjecting the 
bodies to the embalming process. A case has been 
reported1 having for conspicuous features a fracture 
of the cribriform plate, a punctured wound of the 
brain, and a foreign body, in the shape of the ferule 
of a fencing cane, lying at the side of the clinoid 
processes of the sphenoid bone. While engaged in 
a friendly exercise at fencing, the patient had re- 
ceived a thrust from his opponent, which had entered 
the nose and passed with but little opposition through 
the cribriform plate to the middle of the base of the 
skull (compare fig. 2, Plate XXIV.). Operation upon 
the nasal chambers, as, for example, the removal 
of a polypus by evulsion, has in more than one in- 
stance been followed by inflammation of the soft parts 
overlying the cribriform plates. When the olfactory 
nerve is absent, as in cyclops monsters, the olfactory 
foramina of the cribriform plates are absent also. 
Cerebral hernia has occurred through the cribriform 
plate into the nasal chamber.2 Retzius refers to a 
case of simple congenital meningocele at the root of 
the nose in a woman aged twenty-five. 
THE VOMER. 
The vomer (fig. 2, Plate XX.) is a thin rhomboidal 
lamina of bone situated in advance of and beneath 
the body of the sphenoid and between the nasal 
chambers. It presents for examination an anterior, 
posterior, superior, and inferior border, and a right 
and a left surface. The anterior border is oblique from 
above downward and from behind forward to articu- 
late with the perpendicular plate of the ethmoid bone 
and the triangular cartilage. The posterior border is 
shorter than the anterior, and is free. It serves to 
separate the posterior nares from each other. The 
superior border presents a V-shaped depression for 
articulation with the rostrum of the sphenoid bone, 
and is furnished with stout everted lips, termed the 
wings of the vomer (alse). The lateral edge of each 
wing unites with a thin lamina from the internal 
pterygoid process of the sphenoid bone and the sphe- 
1 Dublin Journ. of Med. Sci., xi. 349. 
2 Velpeau, Chirurg. Anat., i. 104; Spring, Hernie du Cerveau, 
Brussels, 1855. THE BONES OF THE HEAD. 
133 
noiclal process of the palatal bone. In carefully 
macerated specimens of the vomer a small ridge is 
seen, which limits the plane of the posterior nares 
superiorly. The surfaces of the vomer are smooth 
save where they are grooved for the naso-palatine 
vessels and nerves. 
Structure.-The vomer is composed of two layers 
of bone, which slightly diverge at the anterior bor- 
der. In fresh specimens there is found in the groove 
in this way formed a thin rod of cartilage, which is 
continuous with the triangular cartilage. 
Articulation.-The vomer articulates with the 
sphenoid, ethmoid, palatal bones, and the superior 
maxillae, and with the triangular cartilage. 
Development.-The vomer arises from tfye peri- 
chondrium of the septal cartilage by a single centre 
of ossification. 
Remarks.-The vomer presents the following vari- 
ations : The two layers composing the bone are very 
distinct-an evidence of unusual degree of persistence 
of the septal cartilage. The wings may be greatly 
exaggerated-recalling exostoses. The wings may 
be very small, and the groove between the plates 
anteriorly occupied by calcified cartilage. 
the superior maxilla. 
The superior maxilla (figs. 3 and 4, Plate XX.) oc- 
cupies the space between the orbit and the mouth- 
the zygomatic fossa laterally, and the outer wall of the 
nose medianly. It assists in forming the floor of the 
orbit, the outer side and floor of the nose, and the an- 
terior nares, and affords lodgment for the upper teeth. 
It presents for examination a central portion or 
body, and the nasal, palatal, malar, and alveolar pro- 
cesses. • 
The boundaries of the body correspond pretty accu- 
rately to the shape of a large cavity-the maxillary 
sinus. The antero-posterior section of the body bi- 
sects the sinus at the position of the first molar tooth. 
'The sinus is of a triangular figure. One side of the 
triangle forms the floor of the orbit; another, imper- 
fect one, the nasal side; while between the nasal and 
the orbital borders lies the facial. In a horizontal 
section of the body the posterior border is seen to 
be convex and directed towards the zygomatic fossa, 
hence the name given it of the zygomatic surface. 
The size of the maxillary sinus is subject to great 
variation. It may extend into the malar bone. It 
is occasionally divided into compartments by incom- 
plete vertical septa. 
The orbital surface of the body is a nearly smooth 
plane, and is slightly oblique from within outward. 
Its inner edge articulates with the lachrymal bone and 
the os planum of the ethmoid. Its outer edge joins the 
malar bone at its anterior half, and forms the inner 
border of the spheno-maxillary fissure at its posterior 
half. The orbital surface is marked by a groove run- 
ning from behind forward, which terminates in a canal 
near the front edge. This is the infra-orbital groove 
and canal for the transmission of the infra-orbital 
nerve and artery. The orbital surface may serve to 
cover in the nasal chamber above the middle meatus. 
The inner or nasal surface is imperfect. It presents 
an upper and a lower plate, with a large irregular 
opening between them. When the bones of the face 
are in position, this opening is partially closed by the 
palatal bone, the ethmoidal process of the inferior 
turbinated, and the uncinate process of the ethmoid. 
The lateral or facial surface is concave, and extends 
from the root of the malar process forwards to the 
median line at the anterior nasal aperture. Its junc- 
tion with the orbital plate is marked by a thickened 
border-the infra-orbital ridge-which is continued a 
short distance upon the ascending process. Directly 
below the ridge lies the infra-orbital foramen for the 
nerve and artery of the same name. Extending from 
the infra-orbital foramen to the alveolar process, to 
the outer side of the eminence of the socket for the 
root of the canine tooth, is a depression known as the 
canine fossa. To the median side of the canine depres- 
sion lies the canine eminence, answering in position to 
the root of the canine tooth. Above the incisor teeth 
is seen a smaller depression-the myrtiform fossa. 
The posterior or zygomatic surface is convex. It 
extends from the base of the malar process to the 
nasal aspect of the bone, where it joins the vertical 
plate of the palatal bone. It is separated from the 
orbital surface of its own bone by a sharp line at the 
inner border of the spheno-maxillary fissure. The 
zygomatic surface presents a rounded eminence above 
the alveolus for the last molar tooth, termed the tube- 
rosity. Above it a short distance lie the posterior den- 
tal foramina for the transmission of the posterior 
dental artery and nerves. This surface presents me- 
dianly an articular surface for the pyramidal process 
of the palatal bone. 
The nasal process is the stoutest in the region of 
the face. It is broader below than above, and is in- 
clined upward and slightly backward to articulate 134 
THE BONES 
by a broad, jagged extremity with the frontal bone. 
The origin of the nasal process is best seen from with- 
in the nasal chamber; it here presents a smooth con- 
cave surface defined in front by the sharp compressed 
edge of the outer border of the anterior nasal aper- 
ture, and behind by the thickened anterior border of 
the lachrymal groove. This border is traceable up- 
ward to appear at the outer aspect of the bone on the 
inner wall of the orbit in front of the lachrymal bone, 
so that the lachrymal groove lies upon the inner side 
of the nasal process below and terminates at its outer 
side above. The nasal process is marked within by 
two transverse ridges, the lower for the inferior turbi- 
nated bone, the upper for the middle turbinated. The 
outer or facial surface may be divided at the level of 
the infra-orbital ridge into an upper and a lower por- 
tion. The upper portion is slightly concave exter- 
nally, and marked by minute depressions thought to 
be traces of the development of the bone. Its anterior 
edge is articulated with the nasal bone. The infra- 
orbital ridge is here observed to be continuous with 
the anterior border of the lachrymal groove. 
The palatal process is a horizontal plate of bone 
extending the entire length of the oral aspect of the 
superior maxilla. It is thinner at its middle than at 
cither border. It is best defined opposite the second 
molar tooth, where it arises from the alveolar process 
and presents a thin transverse border for union with 
the palatal process of the palatal bone. It joins its 
fellow of the opposite side at the median line by a 
vertically serrate border; the upper edge of which, 
termed the crest, is produced to articulate with the 
vomer. The internal border of the palatal process is 
broader in front than behind, and it is continuous with 
the mesial border of the alveolar process at about the 
site of the anterior palatine canal. This foramen is 
best seen from beneath when the superior maxillae are 
in position. It then presents an ovoidal depression, 
at the base of which is seen the median suture. Lying 
within this depression are the two minute naso-pala- 
tine canals. At its sides are seen the incisorial fora- 
mina. These two sets of canals transmit the terminal 
branches of the naso-palatine nerves from the nasal 
chambers to the roof of the mouth. The palatal 
process is smooth and concave above to enter into the 
floor of the nose, and roughened below for the attach- 
ment of the mucous membrane of the roof of the 
mouth. The lateral border of this surface is grooved 
for the posterior palatine artery and nerve. 
The alveolar process extends along the under mar- 
gins of the facial and zygomatic surfaces. It is a 
stout curved mass of spongy bone, placed at the sides 
of the hard palate and curved forward at the incisorial 
region to join its fellow of the opposite side at the 
median line. It is well defined within the cavity of 
the mouth, where it forms an angle with the palatal 
process. On the facial and zygomatic aspects it is 
continuous with the body of the bone. The alveolar 
process is divided into eight sockets or alveoli, cor- 
responding in size and shape to the teeth; those of the 
molar teeth being broad, the canine circular, and the 
incisors somewhat compressed from side to side. The 
bases of the sockets of the roots of the first and second 
molars appear as eminences within the maxillary 
sinus. That of the canine tooth is the deepest, and 
forms the canine eminence on the facial border. 
The malar process is broad, and is seen at the junc- 
tion of the facial and zygomatic surfaces. It is di- 
rected horizontally outwards, and articulates with the 
malar bone. 
Structure.-The body of the superior maxilla is 
composed of thin laminae. The ascending process is 
compact, but the alveolar process is made up entirely 
of small-meshed but stout cancelli. 
Articulation.-The superior maxilla articulates 
with the bone of the opposite side, the frontal, nasal, 
ethmoid, lachrymal, palatal, malar, and inferior tur- 
binated bones, as well as with the vomer. It also 
joins the triangular cartilage. 
Development.-Our knowledge of the development 
of the superior maxilla is in a less satisfactory state 
than that of any other bone. Its centres appear in 
membrane and soon coalesce. Writers agree, how- 
ever, that separate centres appear in the alveolar 
arch, the nasal, facial, orbital, and malar portions. 
Inferences deduced from the study of comparative 
anatomy and structural defects lead us to believe that 
the incisorial portion arises from two centres of ossi- 
fication, one on either side of the median line in the 
position of the premaxillaa of lower animals. Develop- 
ment begins as early as the sixth or seventh week. 
In complete cleft palate the incisorial portion is sepa- 
rated from the remaining portion of the bone of the 
side corresponding to that on which the cleft occurs, 
or on both sides if the clefts in the alveolar arch are 
double (bilateral). Moreover, grave lesions in the 
development of the face indicate that the lateral 
parts of the superior maxilla arise within the first 
pair of visceral arches, while the incisorial centres 
arise within the lower free edge of the median fronto- 
nasal process of the embryo which descends in front 
of the ethmo-vomcrine septum. THE BONES OF THE HEAD. 
135 
When the premaxillae unite at the median line, the 
pair may be denominated the intermaxillary bone. 
The suture between the premaxillae may be detected 
until the sixth year, and on the hard palate as late as 
the adult period. 
Remarks.-In diseased conditions the identity of 
the premaxilla is occasionally established. Mr. Hugh- 
lings Jackson1 describes the case of a boy three years 
of age who suffered from severe inflammation of the 
mouth followed by the exfoliation of the right pre- 
maxilla, the maxilla proper not being affected. The 
bone contained two incisor teeth. Mr. Bryant2 gives 
an instance of the same disease in an adult aged forty- 
four, from whom an exfoliation was secured which 
corresponded to the premaxilla. 
The following is an exceedingly interesting case in 
this connection which came under the notice of the 
writer: A gentleman, aged sixty, was much annoyed 
by a defect which prevented his dentist fitting a plate 
for artificial teeth. The patient was edentulous, and 
had had from early childhood a cleft in the incisorial 
portion of the upper jaw, which, as he had been in- 
formed by his parents, was caused by the loss of 
bone following an attack of measles. The cleft was 
a little to the right of the median line, and extended 
upward to the floor of the nose and backward along 
the roof of the mouth about an inch. The sides of 
the cleft were for some distance in contact, but pos- 
teriorly a delicate.probe could be introduced into the 
nose. The entire right side of the dental arch was 
more incurved than the left. Acquired malformation 
of the hard palate, the result of early loss of the left 
premaxilla, was diagnosed. 
The fact that both upper and lower maxillae are 
derived from membrane would apparently explain 
the rarity of cartilaginous tumors, and would equally 
make clear the meaning of the fact expressed by 
Agnew3 as follows :- 
" Fibrous tumors of the upper jaw are quite uncom- 
mon, although frequently met with in the lower max- 
illa. A considerable proportion of all the morbid 
growths of the lower jaw belong to this class." 
The case described by Mr. Hutchinson,4 in which a 
cartilaginous tumor of the upper jaw occupied the 
canine fossa, but did not grow from the bone, must 
be considered in every way anomalous. 
The law of symmetrical distribution of diseased 
action is not without example in the upper jaw, 
though instances of it are rare. The cases of Lebert 
and Murchison (see the section on the Lower Jaw) 
also included lesions of the upper jaw. Fergusson,1 
in commenting on a case of tumor in the alveolus 
and median line of the upper jaw, says that disease 
in one maxilla is common, but it is rare to find it 
implicating both maxillae. 
Many diseases of the superior maxilla take their 
origin from the mucous lining of the maxillary sinus. 
A tumor growing in all directions from the sinus 
will encroach within on the nasal chamber, above 
on the orbit, without and forward on the face, and 
downward into the mouth. The most common form 
of distortion, or at least the most noticeable, is 
the obliteration of the canine fossa. At times the 
bone becomes thinned, and will crackle under the 
finger like a piece of parchment. In a case men- 
tioned by C. H. Moore,2 a tumor of the right superior 
maxilla, of about two years' duration, formed about the 
position of the canine fossa, where a conspicuous thin- 
ning of the wall ensued. This eventually gave way, 
and the fluid contained in the sinus escaped into the 
mouth. In other instances, the collection will open 
upon the cheek, as described by J. H. Howard.3 At 
a later stage of cystic distension, the entire anterior 
wall of the sinus may bulge forward and give rise to 
deformity. After the anterior, the most yielding wall 
of the sinus is the orbital. As a result of pressure 
in this direction, the eyeball may be displaced and 
protrude, the conjunctiva becoming thickened and 
inflamed. Pressure toward the nose and toward 
the hard palate is relatively infrequent. The last- 
named writer mentions a case in which the nostril 
was thus encroached upon. It is a curious fact that 
cystic distension does not involve the lachrymal duct. 
Tumors of a fibrous and encephaloid nature, on the 
other hand, may cause overflowing of the tears from 
such involvement,4 as well as paralysis of sensation in 
the affected part, as witnessed by Fergusson.5 The 
origin of solid tumors involving the upper jaw is so 
obscurely localized that little of definite value can be 
written of it. That necrosis of so vascular a group of 
bones as those composing the upper jaw should occur 
in the degree seen in the following case is certainly 
very exceptional: In a male child, aged four years, 
1 Med. Times and Gazette, 681, 1862, part 2. 
2 Trans. Path. Soc. London, 1868 ; also Lancet, 1864, 153. 
3 System of Surgery, ii. 955, 962. 
4 Med. Times and Gazette, 1850, 231, part 2. 
> Ibid., 1860, 35. 
2 Trans. Clinical Society of London, iii. 39. 
s Ibid., v. 131. 
4 Dr. Mason Warren, Surgical Contributions ; also Heath on 
Diseases of the Jaws, p. 256. 
5 Lancet, 1861. 136 
THE BONES. 
a month after he had recovered from an attack of 
measles, an offensive discharge was announced from 
the right nostril. The right eye became prominent, 
and finally protruded conspicuously. The cornea 
sloughed, and the globe gave way. The right 
maxilla, the malar, and part of the sphenoid bone be- 
came necrosed. The child died at the end of eleven 
weeks of phlebitis of the ophthalmic vein, involving 
the base of the brain. 
PALATAL BONE. 
The palatal bone (figs. 5 and 6, Plate XX.) occupies 
the space which would otherwise exist between the 
superior maxilla and the pterygoid process. It is 
placed to the outer side of the nasal chamber and to 
the posterior part of the floor of the nose and roof of 
the mouth. It enters also into the composition of the 
floor of the orbit; and it assists in closing the posterior 
ethmoidal cells, and the inner border of the spheno- 
maxillary space and fissure. It is in the form of the 
letter L, with the angle produced downwards and the 
vertical member notched above. In addition to a 
palatal and vertical plate, it presents a pyramidal, 
an orbital, and a sphenoidal process. 
The palatal plate corresponds to the plate of the 
same name of the superior maxilla. It is concave 
above to form part of the floor of the nose, and is 
nearly flat below, but smooth to enter into the con- 
struction of the roof of the mouth. Its anterior bor- 
der is serrated for articulation with the palatal 
plate of the superior maxilla; the posterior is con- 
cave, to form the posterior border of the hard palate. 
Its inner border, when united with that of the oppo- 
site side, is produced posteriorly to form the posterior 
nasal spine. The junction of the horizontal and ver- 
tical portions of the bone is marked by an opening- 
the posterior palatine canal-and by a sharp ledge of 
bone extending inward from the base of the pyra- 
midal process, to give attachment to the palatal apo- 
neurosis. 
The vertical plate extends from the floor of the nose 
to the level of the spheno-palatine notch. It is 
smooth externally, when it forms the internal boun- 
dary of the spheno maxillary fossa. Internally it is 
marked by two crests-the upper for the middle tur- 
binated. the lower for the inferior turbinated bone. 
It is grooved along its posterior border (forming the 
posterior palatine groove') for the posterior palatine 
artery and nerve. 
Two processes arise from the termination of the 
vertical plate-the sphenoidal and the orbital. Of 
these, the sphenoidal appears to be the continuation 
of the vertical plate. It passes upward and back- 
ward as a thin wafer-like lamella, and, curving in- 
ward at its extremity, lies along the inner border of 
the base of the internal pterygoid plate to join the 
vomer. It thus may be said to enter into the con- 
struction of the roof of the nose. The orbital process 
is more robust, and is hollow. It forms the anterior 
boundary of the spheno-palatine notch, and enters into 
the floor of the orbit posteriorly and the spheno- 
maxillary fossa. It articulates with the superior max- 
illa, the sphenoid, and the ethmoid bones. 
The pyramidal process or tuberosity is an elongated 
wedge arising at the union of the vertical with the 
palatal plates. It is directed outward and backward 
to be received into the pterygoid notch of the sphenoid 
bone. It is marked for articulation with the internal 
and external pterygoid plates. Between these is a 
smooth surface which enters into the pterygoid fossa. 
The spheno-palatine notch, which lies between the or- 
bital and sphenoidal processes, is converted into a fora- 
men by the sphenoid bone, or by a plate of the palatal 
uniting the processes. 
Articulation.-The palatal bone articulates with 
the bone of the opposite side, and with the superior 
maxilla, the ethmoid, the sphenoid, the inferior turbi- 
nated bones, and the vomer. 
Development.-The palatal bone arises from a 
single centre of ossification which appears at the 
seventh or eighth week. 
EXPLANATION OF PLATE XX. 
Fig. 1. The ethmoid bone, seen from the lateral aspect. 
For " Christa galli" read " crista galli." 
Fig. 2. The vomer, seen from the side. 
Fig. 3. The superior maxilla, seen from in front and the side. 
Fig. 4. The superior maxilla, seen from the median aspect. 
Fig. 5. The palatal bone, seen from the lateral aspect. 
Fig. 6. The palatal bone, seen from the median aspect. PLATE XX 
Fig 1 
Fi$ 2 
Fig. 3 
Fig.4 
Fig 5 
Fie . 6 
T. 3 in cl air & S on, Li th. TTIE BONES OF TIIE HEAD. 
137 
dependent upon bloodvessel changes. It is thus apt 
to become hypertrophied from catarrhal inflamma- 
tions, and is frequently lost by necrosis through the 
inflammatory infiltrations of syphilis. Among civil- 
ized races it is almost invariably asymmetrical, the 
larger bone always lying in the larger nasal chamber. 
In congenital cleft of the hard palate, the bone de- 
scends along its obtuse lower border and tends to 
occupy the cleft. The anterior narrowed extremity 
is a rudiment of the prolonged " alinasal" of quadru- 
peds, which, as the name implies, reaches to the snout, 
and lies directly behind the space to the outer side of 
the nostril. This ridge in the human skull may reach 
the anterior border of the anterior nasal aperture, but 
generally ends at a point a short distance within. 
MALAR BONE, 
The malar bone is situated at the side of the face, 
where it joins the cranium. It forms part of the 
temporal fossa and the anterior portion of the outer 
border of the orbit. It is associated with the zygo- 
matic process of the temporal bone to form the zygo- 
matic arch. It presents for examination a maxillary, 
a zygomatic, and a frontal process. 
The maxillary process is broad and irregular. It 
articulates with the malar process of the superior 
maxilla. The frontal process forms the inferior third 
of the outer edge of the orbit, and articulates with 
the external lateral process of the frontal bone. A 
thin plate is directed inward from the frontal process 
its entire length, to join the great wing of the sphe- 
noid bone. It is called the orbital plate, and helps to 
separate the orbit from the temporal fossa. A small 
portion of the orbital process ordinarily remains free, 
and enters into the outer border of the spheno-maxil- 
lary fissure. 
The zygomatic process is a broad thick plate passing 
backward from the side of the bone. Its upper margin 
is horizontal, and is continuous with the frontal pro- 
cess to form the fronto-jugal border. Its course is 
oblique, and continuous with the malar ridge of the 
superior maxilla, to form the maxillo-jugal border. 
The zygomatic process articulates with the corre- 
sponding process of the temporal bone through a 
serrate suture. 
The malar bone presents a subcutaneous or facial 
surface. It is smooth, somewhat convex, and fur- 
nished with several minute foramina for the malar 
branches of the ophthalmic nerve. A temporal sur- 
face is formed by the temporal aspects of the zygo- 
matic and frontal processes, and an orbital surface 
INFERIOR TURBINATED BONE. 
The inferior turbinated bone is an elongated scroll 
of bone appended by its outer border to the inner 
wall of the maxillary sinus, and to the lower crest of 
the palatal bone. It consists of a body and three pro- 
cesses, the maxillary, the lachrymal, and the ethmoidal. 
Its inner border, at its anterior edge, is fixed to the 
inferior crest of the nasal process of the superior 
maxilla. The bone is curved from within outward, 
presenting a convexity toward the nasal chamber, 
grooved for vessels and nerves. The entire bone is 
of papery consistency, and is marked by minute de- 
pressions and elevations for the retention of the mu- 
cous membrane. 
The maxillary process is a hook-like process of a 
semicircular shape. Hence the name, sometimes given 
to it, of the auricular process. It is applied to the inner 
wall of the maxillary sinus, and serves to maintain 
the bone in position. The lachrymal process passes 
upward and forward to articulate with the inner por- 
tion of the lachrymal bone. The ethmoidal process 
arises on the same plane a little further back, to effect 
a junction with the uncinate process of the ethmoid 
bone. The lachrymal and ethmoidal processes aid in 
defining the nasal wall of the maxillary sinus. 
Articulation.-The inferior turbinated bone ar- 
ticulates with the superior maxilla, the palatal, the 
ethmoid, and the lachrymal bones. 
Structure.-Dr. II. J. Bigelow1 describes in the 
inferior turbinated bone a special arrangement of the 
cancelli, which he believes allies it with the erectile 
cavernous tissue as seen in the penis. The cancelli 
of the bone freely intercommunicate by irregular aper- 
tures, are lined with connective tissue, and are sub- 
divided by bands of the same material. During life, 
blood is supposed to occupy these spaces, and to assist 
in maintaining the cushiony appearance of the mu- 
cous membrane over the turbinated bones, as well as 
to aid in closing the nasal chambers during attacks 
of congestion of the mucous surfaces. A similar ap- 
pearance is seen in the middle turbinated bone. 
Development.-It arises from a single centre at 
about the fifth month. 
Remarks.-The inferior turbinated bone, receiving 
its supply through the vessels supplying the mucous 
membrane covering it, is liable to errors of nutrition 
1 Boston Medical and Surgical Journal, 1875. 138 
THE BONES 
by the orbital aspects of the frontal and malar pro- 
cesses. 
Structure.-The malar bone is composed of stout 
lateral plates with intervening cancelli. 
Articulation.-The malar bone articulates with 
the frontal, the superior maxilla, and with the zygo- 
matic process of the temporal. 
Development.-The malar bone arises from two 
centres of ossification. Ililgendorf1 states that this 
takes place not infrequently. Sometimes these cen- 
tres remain distinct, when the malar bone has been 
described as "double." 
Remarks.-The facial surface between the orbital 
border and the position of the malar foramen is some- 
times more convex than the rest of the bone. The 
temporal border of the frontal process quite com- 
monly presents a process directed upward at the 
upper third in place of the swollen border, here com- 
monly present. 
the lachrymal bone. 
The lachrymal bone (figs. 1 and 3, Plate XXI.) is 
best seen upon the anterior portion of the inner wall 
of the orbit. It is a thin quadrilateral plate of bone 
lying in front of the os planum, back of the ascending 
process of the superior maxilla, below the internal 
lateral process of the frontal bone, and above the or- 
bital plate of the superior maxilla. It is marked at 
its anterior third by a crest (posterior lachrymal crest) 
which aids in defining the lachrymal groove, the ante- 
rior wall of which is completed by a small crest on 
the ascending process of the superior maxilla-(ante- 
rior lachrymal crest). The groove is converted into a 
canal-the ductus ad nasum-by the aid of the nasal 
process of the superior maxilla and the lachrymal 
process of the inferior turbinated bone. 
Internally the lachrymal bone forms part of the 
outer wall of the nasal chamber. At this point the 
composition of the outer wall is complicated by the 
uncinate process of the ethmoid bone, which passes 
downward and backward to the inner side of the 
lachrymal bone; so that when the lachrymal bone is 
removed, this process occupies in part the opening; 
it thus serves to support the lachrymal. 
The lower border of the lachrymal bone is thicker 
at the termination of the lachrymal crest than else- 
where, for the purpose of giving strength to the pos- 
terior wall of the ductus ad nasum. It articulates 
with the superior maxilla at the inner wall of the 
maxillary sinus, and with the anterior portion of the 
inferior turbinated bone. 
Articulation.-The lachrymal bone articulates 
with the frontal, the os planum of the ethmoid, the 
superior maxilla, and the inferior turbinated bones. 
Development.-The lachrymal bone arises from 
a single centre of ossification which appears about the 
eighth week. 
Remarks.-The lachrymal bone may be much re- 
duced in size or be absent. For anomalies, see Gru- 
ber,1 and Luschka,2 Gegenbauer,3 and the writer.4 
THE NASAL BONE. 
The nasal bones (figs. 2 and 3, Plate XXII.) are situ- 
ated at the upper portion of the external nose. Each 
bone is longer than wide, and thicker above than be- 
low. It is smooth and gently convex from side to side 
on its facial surface, and concave upon the nasal, where 
it is grooved for the nasal nerve. The upper margin 
is serrated for articulation with the frontal bone, and 
at the nasal spine. The inferior margin is continuous 
1 Muller's Arcliiv fur Anat. 1848, xiv. p. 413. 
8 Ibid., 1858, p. 304. 
3 Zeitsch. fur Morpliologie, 1881. 
4 Amer. Journ. Med. Sci., Jan. 1870. 
1 Virchow's Archiv, 1879, 190. 
EXPLANATION OF PLATE XXL 
Fig. 1. The lachrymal bone, seen from the median aspect. 
Fig. 2. The inferior turbinated bone, seen from the lateral 
aspect. 
Fig. 3. The lachrymal bone, seen from the lateral aspect. 
Fig. 4. The malar bone, seen from the lateral aspect. 
Fig. 5. The malar bone, seen from the median aspect. 
Fig. 6. The inferior maxilla, seen from behind, and some- 
what foreshortened. 
Fig. 7. The inferior maxilla, seen from the side. PLATE XXI 
Fig 1 
Fig. 2 
Fig. 8 
Fig.4 
Fig 5 
Fig . 7. 
Fig. 6 
1'. Sinclair & Son,LitL. THE BONES OF THE HEAD. 
139 
with the upper lateral cartilage of the nose, and is 
marked by a notch for the transmission of the nasal 
branch of the ophthalmic nerve. The median edge 
of the nasal surface forms a slight projection, which 
has received the name of the ngsal crest. 
Structure.-The nasal bone is of enormous rela- 
tive thickness at its upper third: the lower portion 
is almost laminar in consistence. 
Articulation.-Each nasal bone is joined to its 
fellow of the opposite side, to the frontal bone, to the 
ascending process of the superior maxilla, and to the 
perpendicular plate of the ethmoid bone. 
Development.-The nasal bone arises from a single 
centre of ossification, which appears about the eighth 
week. 
Remarks.-The articulation at the upper portion 
of the bones gives the nasals great strength in resist- 
ing the shocks of blows. The weight of such blows 
is in great part received by the cranium through 
the medium of the nasals. Blows received upon the 
side of the nose may break or displace these bones 
with comparative ease.-That the nasal bones are in 
part sustained in position by the perpendicular plate 
of the ethmoid bone is made evident by the sinking 
of the osseous part of the external nose in loss of 
this plate by necrosis. The place of the nasal bones 
when these are congenitally absent, as is infrequently 
the case, is taken by the ascending process of the su- 
perior maxilla. It may be composed of a single bone 
lying below the conjoined ascending processes of the 
superior maxillae.1 In the cyclops variety of monster, 
which is characterized by an imperfect development 
of all the parts lying between the orbits, the rudi- 
ments of the nasal bones occupy a narrow projecting 
mass of skin-covered tissue entirely separated from 
the superior maxilla and the ethmoid bone, but in 
continuity through the normal attachment with the 
frontal bone. 
THE INFERIOR MAXILLA. 
The inferior maxilla or lower jaw (figs. 6 and 7, 
Plate XXI.) is the largest and most massive bone of 
the face. It forms the boundary of the under part of 
the anterior and the lateral region of the face, where its 
lower border can be defined under the skin. It con- 
sists of a horizontal arch, with its curves directed in 
front and its sides elevated at an angle behind. The 
bone is moved on the base of the skull at the temporal 
bone by powerful muscles. 
The lower jaw is composed of two halves; after 
their union it is convenient to divide the bone into a 
body, or horizontal portion, and two ascending por- 
tions or rami. 
The body of the bone laterally is marked above 
by the edge of the alveolar process, and below by a 
thickened, rounded border. In the median line at the 
point of union of the primitive halves is a linear ridge 
-the symphysis. The widened and projecting basal 
extremity of this line is called the mental process. At 
the side of the symphysis, on a line with the lateral 
incisor tooth, is the incisor fossa, from which the 
Levator Labii Inferioris arises. Below this point, 
and to its outer side, is a shallow depression for the 
Depressor Anguli Oris muscle. The line of inser- 
tion of the Platysma Myoides muscle lies below the 
latter, on the basal border. Opposite and below the 
interspace between the second molar and first bi- 
cuspid, and about midway between the basal border 
and the teeth, is seen the anterior dental foramen, 
which affords exit to the inferior dental nerve and 
artery. The basal border of the body near the ramus 
is grooved for the reception of the facial artery. Ex- 
tending obliquely upward and backward to the ante- 
rior root of the coronoid process is the external oblique 
line. 
The median side of the body is conspicuously divided 
by an oblique ridge, which extends from the base of 
the coronoid process downward and forward. This 
has received the name of the mylo-hyoid ridge, and 
serves for the origin of the Mylo-Hyoid muscle. Be- 
tween this riclge and the molar teeth slips of the Buc- 
cinator and Superior Constrictor muscles are attached. 
At a point below the canine teeth, a smooth depres- 
sion supports the anterior border of the sublingual 
salivary gland. Below the mylo-hyoid ridge, a small 
groove running nearly parallel therewith receives the 
mylo-hyoid nerve and artery. A well-marked oval 
depression near the basal border anteriorly is for the 
insertion of the Digastric muscle. At the lower part 
of the symphysis are found the genial tubercles, ordi- 
narily composed of four processes-two on either side 
of the median line. The superior process is for the 
origin of the Genio-Hyo-Glossus, and the inferior for 
the Genio-IIyoid muscle. 
The ascending portion, or ramus, is imperfectly de- 
fined from the body anteriorly. Posteriorly it pre- 
1 J. Van der Hoeven, Jr., Zeitschr. fiir Wissenschaftliche Zoologie, 
xi., 1862, p. 138. 140 
THE BONES. 
sents a robust, rounded border, which is separated 
from the basal portion of the body by the angle. The 
outer surface of the ramus is in great part roughened 
for the attachment of the Masseter muscle. It pre- 
sents two conspicuous processes, the coronoid in front 
and the condyloid behind. Between them is a deep 
hollow, the sigmoid notch. The median aspect of the 
ramus is conspicuously marked by the posterior dental 
foramen for the entrance of the inferior dental nerve 
and artery. The anterior margin of this opening is 
produced into a thin plate of bone, pointing back- 
ward, which gives attachment to the deep fold of deep 
fascia known as the internal lateral ligament. The 
canal between the anterior and the posterior dental 
foramina is termed the dental canal. It passes beneath 
the alveolar process, and sends veins and bloodvessels 
to the teeth. At its beginning it lies near the inner 
surface of the bone, but towards the first molar tooth 
it holds a more central position in the jaw, and ends 
abruptly externally at the mental foramen. 
The coronoid process is flat and pointed. It is di- 
rected slightly forward. It is thin at its upper por- 
tion, but thicker below. Its front edge is nearly 
straight, and presents at its base behind the third molar 
tooth a groove, within which is held a slip of the 
Temporal muscle, as well as the Buccinator muscle. 
Its posterior edge is thin, and continuous with the 
curve of the sigmoid notch. The lateral surface is de- 
voted to the insertion of the Temporal and Masseter 
muscles, and the median to the Temporal alone. 
The condyloid process, more massive than the coro- 
noid, is a continuation of the posterior free margin of 
the ramus. It presents for examination a neck and 
an articular surface. The neck corresponds to that 
portion of the process directly below the articular. It 
is compressed from behind forward, and receives at 
its inner portion a shallow depression for the Exter- 
nal Pterygoid muscle. The outer margin of the neck 
is marked by a minute rounded process, the tubercle 
for attachment of the external lateral ligament. The 
articular surface is convex from before backward, 
abruptly arched from within outward. It is often 
angulated at a point answering to the axis of the 
ramus. The articular surface is directed inward and 
somewhat backward. The production of the lines of 
inclination of the two surfaces would cause them to 
intersect each other at the anterior margin of the 
foramen magnum. 
and a left half; (A) as divided into the alveolar portion 
as one part, and the remainder of the bone as another; 
(c) as divided into a region of muscular impressions as 
one part, and the remaining non-muscular region as 
the other; (d) as divided by the mylo-hyoid ridge 
into facial relations (z. e. all the parts above the ridge 
and the entire outer surface of the bone) and cervical 
(i. e. all the parts below the ridge); (e) as compared 
with a long bone, especially with reference to the 
localization of tumors. 
(a) The lower jaw as divided into a right and a left 
half.-The lower jaw, in common with other sym- 
metrical parts of the skeleton, exhibits those curious 
connections between physiological and morbid action 
often witnessed in the long bones. This symmetrical 
distribution of disease is disturbed, however, by the 
union of the halves of the bone at the symphysis. 
It is probable that in lower mammals, such as the 
ruminants and the marsupials, in which the halves 
never unite, the symmetrical distribution of disease 
might be found better expressed than in man. 
The following instances may be cited to show that 
disease tends to occupy the sides of the jaw rather 
than the median line, and that excesses of nutrition 
are apt to occur on either side of the symphysis in an 
equal degree. In confirmation of the latter statement, 
we may refer to those extraordinary developments of 
symmetrical hyperostosis recorded by Lebert1 and 
Murchison ;2 and in proof of the former, to the clinical 
fact that growths of all kinds are vastly more common 
on the sides than on the median portion of the jaw. 
The only examples known to the writer, of a growth 
beginning on one side of the bone and passing across 
the median line, are the following: first, a tumor 
termed by Prof. Gross3 hematoid which began on 
the left side just behind the cuspid tooth, and passed 
across the line of symphysis as far as the lateral inci- 
sor of the right; and second, the one described by 
Mutter,4 which occupied the symphysis and about two- 
thirds of the left ramus of the bone. Hyrtl5 alludes 
to a case of exostosis of the symphysis. 
(b) The lower jaw as divided into the alveolus as one 
part, and the remainder of the bone as another.-This 
division is an important one to remember, for the fol- 
lowing reasons: The alveolus is developed with the 
teeth and disappears with the teeth ; it is an out- 
growth from the jaw for a specific temporary purpose. 
1 Atlas, pl. xxxii. fig. 1. 
2 Trans. Path. Soc. London, xvii. 243, pl. 10, xii. 
3 System of Surgery, i. 485. 
4 Amer. ed. of Liston's Surgery, 299. 
5 Topograph. Anatomie, i. 324. 
Remarks.-The inferior maxilla can be studied 
with great advantage for practical purposes from the 
following points of view: (u) As divided into a right THE BONES OF THE HEAD. 
141 
Jno. Hunter1 declared that the "alveolar processes of 
both jaws should rather be considered as belonging 
to the teeth than as parts of the jaws." 
It follows that all diseases of the alveolus are to 
be considered as dental in their significance. Thus 
epulis is peculiarly an alveolar disease. A tooth in 
any portion of the jaw other than that of the alveolus 
is as much out of place as though it were lodged in 
another bone. There is little doubt that the third 
permanent molar, when in the position so often as- 
sumed by it at the end of the alveolus, half within and 
half without the dental arch, with its roots, it may be, 
deflected within the compact and resisting tissue of the 
base of the coronoid process, acts as a foreign body; 
and as a splinter in the flesh provokes inflammation, 
so such a tooth is of necessity a fertile cause of diseased 
action about the angle of the jaw. Should a tooth be 
lodged beneath the alveolus, as in the encysted form, it 
either gives rise to chronic abscess or provokes those 
common tumors, the odontomes, which frequently are 
of such fearful import. Cystic disease about the angle 
of the jaw is so often excited by a misplaced third 
molar that the teeth should always be examined in 
attempting to diagnose this condition. In a case men- 
tioned by Bordenave,2 fetid matter from the collection 
about the wisdom-tooth escaped after removal of the 
second and third molars. 
Dr. Mason Warren3 describes a number of cases of 
cystic tumor of the angle of the jaw. In one of these 
the growth began by a swelling at the root of the 
third molar of the right side. By the end of several 
years it involved the whole right ascending ramus. 
It was of a globular shape, extended back under the 
lobe of the ear, and forward to encroach upon the 
cavity of the mouth. In another the growth extended 
backward into the parotid region, upward upon the 
face, and "inward to involve the right half of the 
palate, where it was covered by a highly irritable 
cedematous mucous membrane resembling that cover- 
ing malignant growths in the same locality." There 
was a slight discharge of fluid through the remains of 
the socket of the last molar. This being enlarged, the 
cystic character of the growth was made clear. In a 
third instance, a growth of six years' duration, which 
attained the size of a hen's egg, began in the socket 
of the third molar. 
It would be interesting to trace the connection be- 
tween defects of the teeth-germs and congenital cystic 
tumor of the lower jaw, such as is described by Coate,1 
occurring on the right side of the lower jaw of an in- 
fant three months of age. Death ensued from ex- 
haustion2 following an operation for its removal. 
That the body of the jaw is a growth distinct from 
the alveolus is shown in the study of cases of con- 
genital defects of the bone. In the following rare 
manifestation of imperfect development characterized 
by permanent fixation of the two halves of the bone, 
we have, as the adult condition is attained, the jaw 
preserving the proportions of the infant as far as the 
body is concerned, while the teeth and alveolus are as 
well pronounced as in a normal jaw. Mr. Humphry3 
describes the case as follows:- 
"The lower jaw is almost completely fixed, with 
the molar teeth clinched against the upper, so that 
there is no perceptible interval between them. The 
jaw is broad or natural at the angles, and the angular 
parts have descended nearly to their proper level; 
but the arch formed between the two angles is ex- 
tremely small. Indeed, the body and the mental por- 
tions of jaw run forward scarcely at all, and do little 
more than pass from one angle to the other. The 
chin is in a plane two inches behind the alveolar edge 
of the upper jaw, instead of being a little in front of 
it. There has been, therefore, a failure, amounting to 
at least two inches, in the growth of the body of the 
jaw in length; and it is also less deep than natural. 
The failure, however, has not been shared in quite an 
equal degree by the alveolar portion. This forms a 
segment of a larger circle, taking a wider sweep, and, 
consequently, overhanging the lower part of the body 
of the jaw. By this means greater room is given for 
the teeth, which are as numerous and as large as 
natural; and they are disposed in a slanting fan-like 
manner, so as to bring the crowns of the molars and 
hinder bicuspids into contact with those of the upper 
jaw." 
(c) The lower jaw divided into muscular impressions 
as one part, and the rest of the bone as the remaining 
part.-Both sides of each ascending ramus may be 
said to be large muscular impressions-the lateral for 
the Masseter, the median (less completely covered) for 
the Pterygoid muscles, while the tendon of the Tem- 
poral muscle embraces the coronoid process. The 
arch of the bone can be called, for the most part, a 
non-muscular area; for with the exception of the in- 
1 Palmer's Hunter, i. 4. 
2 Surgical Essays, Sydenham Series. 
3 Surgical Observations, with Cases and Operations, Boston, 
1867, 72. 
1 Sydenham Retrospect, 1861. 
2 Foi' a cystic tumor not apparently connected with the teeth, yet 
strictly alveolar, see R. Adams, Med. Times and Gazette, 1857, 484. 
3 Med.-Chir. Rev., 2d series, xxvii. 1862, 288. 142 
THE BONES 
sertion of the Digastric muscle at the small digastric 
fossa, and of the Genio-IIyoid group at the genial 
spine, the muscles here (viz., the Mylo-Hyoid muscle 
within, at the ridge of the same name, and the Depres- 
sor Anguli Oris and the Platysma Myoides muscles at 
the mental process without) constitute an unimportant 
clement. 
It is particularly with the ascending ramus that 
the muscular impressions are found to be of value in 
the study of lesions and diseased action. In the first 
place, the Masseters act as external cushions protect- 
ing the jaw from direct violence, while the Pterygoids 
act as internal cushions to prevent bilateral disloca- 
tion. In the second, the direct influence exerted on 
the shape of the angle by the Internal Pterygoid is 
often very marked. A condition known as incurva- 
tion of the angle is frequently seen in well-marked 
specimens of the lower jaw. It was at one time 
thought that this peculiarity stamped the individual 
as an example of a low type of man. It is a curious 
fact (only noteworthy from its liability to deceive in 
attempting such generalizations) that the same incur- 
vation of the angle is a constant character in the jaw 
of the marsupials-a low group of the mammalia. 
Another feature of importance is the fixity of the 
ascending ramus by the contraction of the masticatory 
muscles. Other things being equal, the position of 
elevation or depression of the lower jaw will make the 
difference between a dislocation and a fracture. If 
the jaw at the time of the injury be elevated, the 
bone is apt to be broken by the direct violence ap- 
plied to it; if, however, it be depressed, it is more apt 
to be dislocated. The ensuing case is of value in 
illustration of this principle, since the lines of frac- 
ture were doubtless determined by the fixed position 
of the jaw.1 
A young man whilst plowing was thrown down by 
his bullocks running away, and the coulter, catching 
his throat, tore away the entire horizontal portion 
and more than half of the right ramus of the lower 
jaw. "A lacerated wound extended from the right 
mastoid process across the throat nearly to the left 
angle of the jaw; this at its posterior origin had 
entirely divided the whole breadth of the Sterno- 
■Cleido-Mastoid muscle; from the right angle of the 
jaw to near the chin it divided the floor of the mouth. 
It was also met by an oblique laceration from the left 
commissure of the lips, which had quite torn through 
and divided the cheek. The inferior maxilla was 
fractured on both sides, on the right more than half- 
way up the ramus. The bone thus broken and torn 
out of the face was very much denuded of soft parts, 
and at each fractured extremity was, to some extent, 
laid bare of periosteum." Six weeks after the injury, 
the right side of the face was paralyzed; the eye could 
not be closed, nor the mouth entirely.-The specimen 
embraced the entire horizontal portion of the jaw, and 
more than half of the ramus of the right side. The 
ramus had been fractured obliquely backward and 
downward from the root of the coronoid process to 
the middle of the posterior edge. On the left side the 
fracture extended obliquely across the angle, from 
behind the socket of the second molar tooth to just 
in front of the posterior part of the angle of the jaw. 
According to Hamilton,1 fracture of the condyloid 
process almost always occurs just below the insertion 
of the External Pterygoid muscle. 
{d) The lower jaw as divided by the mylo-hyoid ridge 
into two groups of relationships-one above {facial), 
the other below {cervical).-The Mylo-Hyoid muscle is 
the floor of the mouth, and abruptly separates the 
inner aspect of the curve of the body from the rest 
of the bone. The relations of this region are entirely 
with the neck. 
(e) The lower jaw as compared to a long bone.-The 
lower jaw resembles a long bone in having compact 
bone without and cancelli within ; in having a well- 
defined canal (somewhat comparable to a nutritive 
foramen) entering it obliquely; and in having an 
active periosteum. It conspicuously differs from a 
long bone in the absence of an epiphysis. The bone 
is thus deprived of an epiphysial period, which is so 
prolific in morbid processes. The ends of the lower 
jaw {i. e. the articular surfaces) are peculiarly exempt 
from disease, the very opposite to what is seen in long 
bones. The only known instance of restricted disease 
at these points is caries, with subsequent hyperostosis. 
Mr. Tatum2 briefly describes a unique case of fluid in 
the temporo-maxillary articulation escaping into the 
external meatus following a lesion of the latter.-The 
lower jaw also differs from a long bone in retaining 
contact with mucous membrane. When in fractures 
of the lower jaw the gum is deeply lacerated, the frac- 
ture at once becomes compound. The ease with which 
this can occur, and the consequent frequency of this 
occurrence, place maxillary fractures in a group en- 
tirely distinct from that of other bones. It has been 
asserted (and on good grounds) that the contact of the 
air and saliva between the ends of the broken bone 
1 J. Thomson, Edin. Med. Journal, 1861, vii. 587. 
1 Treatise on Fractures and Dislocations. 
2 Lancet, 1860, ii. 536. THE BONES OF THE HEAD. 
143 
tends to provoke ostitis and suppuration, with their 
sequelae, constitutional disturbance, and increased risk 
of pyaemia.-The methods of securing vascular and 
nervous supply are widely remote from one another. 
In the lower jaw the bloodvessels and nerves enter 
by a canal which is primarily a groove in the em- 
bryonic bone, and which in necrosis is probably in- 
cluded in great part within the thickened osteogenetic 
periosteum. The dental nerve and vessel are de- 
signed, in a word, for a special object within the jaw, 
as well as to give blood and nerve-supply to the bone : 
thus holding the same relation to the jaw that the 
hepatic artery and nerve hold to the liver. The lower 
jaw is, independently of the teeth, not a very vascu- 
lar bone. It succumbs readily to attacks of necrosis, 
as much from this cause as from its peculiarly ex- 
posed situation. 
The ostitis preceding necrosis in the lower jaw is 
almost always more marked than in a long bone, and 
the pain is greater. The latter symptom often resem- 
bles that of intermittent toothache, thus complicating 
the diagnosis. The swelling of the cheek and gums, 
the difficulty in mastication, and the dysphagia, as 
well as the increased activity of the mucous and sali- 
vary glands, are distinctive symptoms. The presence 
of a sequestrum may, according to Butcher,1 induce 
vomiting and difficulty in speech and swallowing. 
Thus, we have as a result of a branch of a cranial 
nerve being held in connection with the products of 
inflammation-if it be not itself inflamed-an excita- 
tion of a larger circle of sympathies than can arise 
from analogous conditions within a long bone. 
T. Holmes2 mentions the occurrence of fatal hemor- 
rhage from the lingual artery excited by a maxillary 
sequestrum. 
Necrosis of the low'er jaw, as a sequela of measles, 
scarlet fever, smallpox, and typhoid fever-diseases 
whose lesions are for the most part splanchnic-can- 
not be compared to anything seen in the long bones. 
The same remark is true of phosphor-necrosis. It 
will be remembered that this disease always invades 
the jaw through a carious tooth or open socket- 
proving not only that the direct contact of the poison- 
ous agent with the cancelli is requisite, but that such 
contact is possible only in the jaws; for no such rela- 
tionship of cancelli to an open surface is ever seen in 
a long bone. A transverse section of the compact 
structure of the jaw may be compared to a vase. The 
base of the vase is firm and thick; the sides become 
thin as they approach the brim, while the upper sur- 
face is open. If a tooth is removed, the cancelli 
are at once exposed. Applying this explanation to 
the shape of sequestra, it will be seen that a seques- 
trum of the lower jaw or an exfoliation from the ends 
of a broken bone must be more or less U-shaped, as 
the same specimens from a long bone are more or less 
cylindrical. This rule does not apply to syphilitic 
necrosis. 
According to Stanley,1 nine months are required to 
restore a lower jaw through the activity of its perios- 
teum after the bone has been destroyed by necrosis. 
The comparison between the lower jaw and a long 
bone is interesting in studying the subject of re- 
moval. The wide range of sympathies seen in ostitis 
and necrosis of the lower jaw is to be expected in ex- 
cision of that bone. In the event of amputation of 
a limb proving fatal, we commonly find pyeemia or 
secondary hemorrhage playing a ghastly role. While 
these prodromes to fatal disaster are unfortunately 
not wanting in the other operation, we more fre- 
quently find erysipelas and shock the exciting causes 
of sudden death. In summing up the experience 
gained in seven amputations, J. W. Casack2 says: 
"Fatal cases of diffused inflammation succeeding to 
operations in the vicinity of the base of the lower jaw 
are by no means infrequent." In one of his cases, 
the erysipelatous inflammation involved the parts 
about the larynx, death ensuing on the ninth day after 
the operation. Mr. Symes3 narrates a case of excision 
which proved inexplicably fatal on the second day. 
(/) The lower jaw as determining the localization of 
tumors.-From an anatomical standard, this subject, 
of great intricacy in other relations, resolves itself 
into a few simple propositions:- 
1st. When a tumor originates within or beneath the 
gum, and involves the cancelli secondarily, it indubi- 
tably belongs to the alveolar group of morbid growths. 
The different varieties of epulis are thus anatomically 
restricted. 
2d. Fibrous tumors, according to Nelaton, may 
either arise within the body of the bone, when by 
their growth they will encompass the bone, or, having 
their origin beneath the periosteum, they may protrude 
toward the affected side. The same writer affirms 
that they tend to develop toward the cutaneous rather 
than toward the mucous (oral) aspect of the bone. 
Fergusson4 describes a fibrous tumor which lay inclosed 
1 Trans. Path. Soc. London, iii. 169. 
2 Dub. Hosp. Rep., iv. 1827, 1. 
3 Surg. Contributions, 21. 
4 Med. Times and Gazette, 1865, 141. 
* Essays and Reports on Operative and Conservative Surgery. 
R. G. Butcher. Dublin, 1865, 307. 
2 Holmes's System of Surgery, iii. 645. 144 
THE BONES. 
within the expanded and attenuated tables of the jaw. 
The central encapsuling fibrous tumor may involve 
the dental nerve, as described by T. Bryant1 in a tu- 
mor which was removed from the left side of the body 
of the lower jaw of a boy nine years of age. It was 
of two years' duration, and followed a blow received 
six months before. The nerve was found running 
through the centre of the growth. It would appear 
that enccphaloid disease may originate in the dental 
canal, judging by the case reported by Nunneley,2 in 
which the disease was ushered in by numbness of the 
left side of the lower lip. This was followed by vary- 
ing pains in the canine and in two adjoining teeth of 
the same side. The last molar was extracted with a 
view of relieving the toothache. The case, the nature 
of which now became evident, progressed rapidly to 
a fatal termination. 
3d. The lower jaw being in the line of growth of 
epithelial tumors of the lower lip, secondary cancers 
from that source are not infrequently seen. In a case 
coming under the notice of the writer, the disease 
had progressed from the lip along the line of the 
right side of the horizontal portion, opening the oral 
cavity from the side and destroying the alveoli. The 
tongue, thus deprived of lateral support, lolled out- 
ward, and the saliva dropped continually upon the 
neck. Fortunately, these extreme degrees of destruc- 
tiveness are rare, but the probability of secondary 
involvements of the lower jaw from neglected epithe- 
lial cancer should never be overlooked. 
general direction to that of the chorda dorsalis. It 
consists of the basilar process of the occipital bone 
and the body of the sphenoid bone. The vomer and 
the perpendicular plate of the ethmoid bone represent 
parts of the cranio-basic axis projected into the face. 
The chorda dorsalis does not advance further than the 
posterior clinoid processes. The lateral portions of 
the occipital bone and the wings of the sphenoid bone 
arise in pairs from the axis. The nasal bones and 
incisorial portion of the superior maxilla descend 
from the primordial frontal process of the frontal 
bone. The remaining portion of each superior max- 
illa, together with the lower jaw, arises from the side 
of the base of the skull. Each of the facial bones 
not mentioned in the above category appears in its 
appropriate place as a separate ossicle having slight 
morphological significance. 
THE CRANIUM. 
The cranium is divided into the vault and the base. 
The Cranial Vault.-The cranial vault (figs. 1 
and 2, Plate XXII.) is limited anteriorly by the supra- 
orbital arches and the fronto-nasal suture; laterally 
by the zygomatic arch, the orifice of the external 
auditory meatus, and a line running thence along the 
superior semicircular line to the occiput, which termi- 
nates the vault posteriorly. The skullcap or calva- 
rium is defined by a horizontal section of the vault 
about one inch above the external angular process of 
the frontal bone. 
The cranial vault is an ovoidal figure, broader be- 
hind than in front, and abruptly narrowed behind the 
external angular processes. It is slightly compressed 
at the sides at the temporal fossae, and more or less 
expanded behind. The anterior portion of the vault 
is termed the frontal region or sinciput, the pos- 
terior the occiput, and the top the vertex. The side is 
made up in great part of the temporal fossa. 
The forehead (sinciput) is defined inferiorly by the 
supra-orbital margins and the line of the fronto nasal 
suture; superiorly, by a transverse imaginary line 
half-way between the frontal eminences and the coro- 
nal suture; and, laterally, by the temporal ridges. 
Directly between the orbits, and extending thence 
downward one-half the height of the inner margin 
of the orbit and upward about an inch upon the 
supra-orbital curve, is a smooth, rounded space, with 
a faintly convex surface, called the nasal eminence 
(glabella). This eminence corresponds to the anterior 
wall of the frontal sinus, and varies in size according 
THE SKULL. 
The skull (figs. 1 and 2, Plate XXII.) is composed 
of the cranium and the face. It is convenient to in- 
clude between these divisions a third -■ the cranio- 
facial or intermediate portion. 
The term cranium is often applied to the entire 
framework of the head, either with or without the 
lower jaw. In a more exact sense, the cranium is the 
brain-case. The face is a region made up of bones 
that are in cpntact with mucous membrane-the malar 
bone alone excepted-and affords protection to the 
visual, olfactory, and dental organs, besides defining 
the nasal and oral cavities. 
The brain-case and the face are distinct in their 
development. The brain-case possesses a central 
tract-the cranio-basic axis-which corresponds in 
1 Trans. Path. Soc. London, 1858, 352. 
2 Trans. Path. Soc. London, xiii. 1862, 215. THE SKULL. 
145 
to the degree of development of the sinus. At the 
inner third of the supra-orbital arch of each orbit 
is seen the supra-orbital notch, which transmits the 
nerve of the same name. The notch is often con- 
verted into a foramen. A little further out from the 
border is the foramen for the supra-trochlear nerve. 
The frontal and superciliary eminences lie upon 
the line between the eyebrows and the scalp, which 
limits from above downward the " forehead" of 
common language. Ordinarily the " forehead" is 
occupied by the fleshy fibres of the anterior portion 
of the Occipital Frontalis muscle. Occasionally a 
median depression marks the locality of the inter- 
frontal suture, formerly present at this place. 
The back of the vault or occiput answers to the 
ascending portion of the occipital bone above the 
protuberance. It includes the lambdoidal suture, and 
is covered with the hairy scalp. 
The top or vertex (crown) extends from an imagi- 
nary line half way between the coronal suture and 
the frontal eminence to the angle of the occipital bone. 
It embraces the parietal bones between the parietal 
eminences, and is marked in the median line by 
the sagittal suture (inter-parietal). It is evervwhere 
smooth and convex, and covered by the hairy scalp. 
The side of the skull is defined above by a line ex- 
tending from the external lateral process of the frontal 
bone along the temporal ridge, and thence to the 
occipital protuberance, and below by a line answering 
to the lower limitation of the vault. It is made up 
in great part of the temporal fossa, so named from its 
occupancy in the undissected subject by the Tempo- 
ral muscle. The fossa is formed by the temporal, 
parietal, frontal, sphenoid, and malar bones. It is 
deeply concave behind the orbito-temporal septum, 
at a point answering to the greater wing of the sphe- 
noid bone and the pterion, and more shallow and con- 
vex posteriorly, where it is gradually lost upon the 
masto-occipital surface. 
The anterior portion of the temporal fossa is deeper 
in the negro than in the Caucasian type. The tem- 
poral ridge is often represented in the adult skull by 
several faint lines, which answer to the lines of growth 
of the skull. The ridge in narrow skulls approaches 
its fellow of the opposite side to a greater degree than 
it does in broad skulls.1 In congenital arrest of brain- 
growth and in low types of skulls, as in the Austra- 
lian and in some paleo-lithic forms, this approach is 
decided, and resembles that constantly met with in 
the lower animals. 
Measurements.-Draw a line from the fronto-nasal 
suture, and continue it over the top of the skull to the 
occipital protuberance. Cross this line by a second 
extending transversely from the upper border of the 
external meatus. Hyrtl finds that a line drawn from 
the middle of the sagittal suture to the anterior portion 
of the foramen magnum is about two to three inches 
less than the transverse line. It will be seen that the 
skull taken as a whole is most capacious at the junc- 
tion of its posterior with its middle third. Measure- 
ments taken as suggested by curved lines are more 
satisfactory than those taken by means of callipers. 
A fixed relation should be found between the curves 
made by these lines in comparing measurements. 
To aid in securing exact measurements of crania 
the following terms of Broca, as defined by Flower,1 
will be found useful 
Alveolar point. The centre of the anterior margin 
of the upper alveolar arch. 
Subnasal point or Spinal point. The middle of the 
inferior border of the anterior nasal aperture, at the 
base of the nasal spine. 
Naison or Nasal point. The middle of the naso- 
frontal suture at the base of the nose. 
Ophyron. A point situated immediately above the 
nasal eminence, or, more exactly, the centre of the 
supra-orbital line, which, drawn across the narrowest 
part of the forehead, separates the face from the 
cranium. 
Bregma. The point of junction of the coronal and 
sagittal sutures. 
Opisthon. The middle of the posterior margin of 
the foramen magnum. 
Basion. The middle of the anterior margin of the 
foramen magnum. 
Pterion. The point of junction of the frontal, sphe- 
noid, parietal, and temporal bones on the anterior 
parts of the temporal fossa. 
Stephanion. The point where the temporal ridge 
crosses the coronal suture. 
Asterion. The point behind the mastoid process 
where the parietal, occipital, and temporal bones 
meet. 
The vault of the skull differs greatly in degree of 
thickness. It may be exceedingly thin and brittle, or 
excessively thick. 
The skull is thickest at the occiput, where its ave- 
rage measurement is three-quarters of an inch. It is 
thinnest at the temple and the roof of the orbit. 
1 Lucse, J. C. G., Architectur des Menschenschadels, 1857, pl. xv. 
1 Osteological Catalogue of the College of Physicians and Sur- 
geons, London, Part I., 1879. 146 
THE BONES 
In estimating the amount of force required to 
fracture the bones, as well as that required to conduct 
the operation of trepanning, the possibility of the 
occurrence of a cranial vault with thin brittle walls 
should never be forgotten. The vault is always 
thinner at the point of contact with the Pacchionian 
bodies upon its under surface than it is elsewhere. 
While a general relation between the form and 
volume of the brain and the brain-case is conceded to 
exist no exact correlation can be detected between 
the two. The large side of the cranium may corre- 
spond to the smaller cerebral hemisphere. The inner 
and outer layers of the skull may separate widely; 
and the outer may not be concentric or parallel to 
the inner. The frontal sinus is of varying size, and 
bears no relation to the size of the related cerebral 
lobes; nor do the details of the interior of the brain- 
case correspond to the inequalities of the cerebral 
convolutions. 
The Sutures of the Cranial Vault.-The su- 
tures of the cranial vault are the interparietal or 
sagittal, the fronto-parietal or coronal, and the occipito- 
parietal or lambdoidal. 
At the sides of the vault the lower ends of the coro- 
nal and lambdoidal sutures are seen. In addition the 
fronto-malar unites the external angular process of 
the frontal bone with the frontal process of the malar 
bone; and in the temporal fossa sutures arc formed 
by the union of the antero-inferior angle of the parietal 
bone with the tip of the greater wing of the sphenoid 
bone (gparieto-sphenoid), with the parietal bone and 
the squamous portion of the temporal bone (parieto- 
squamosal), and with the postero-inferior angle of the 
parietal bone and the mastoid portion of the temporal 
bone (parieto-mastoid).-The anterior portion of the 
temporal fossa is marked by the nearly vertical fronto- 
sphenoidal and sphenoido-squamosal sutures. 
The occiput exhibits the greater portion of the oc- 
cipito-parietal suture and a portion of the vertical 
limb of the masto-occipital. 
The forehead retains sutures with the facial bones 
where the frontal bone articulates with the frontal, 
sphenoid, ethmoid, lachrymal, superior maxillary, and 
nasal bones. These several sutures can be readily 
named by combining the names of the two bones en- 
tering into them. The unscientific name " transverse 
suture" is sometimes given to all the sutures above 
named. The suture in the median line of the frontal 
bone of the skull of the infant forms the frontal su- 
ture. It rarely persists in the adult. The sutures of 
the vertex are variously dentated, while those of the 
base are slightly sinuate or straight. The degree of 
indentation is subject to great variety, yet presents a 
regular plan of distribution which may be thus epi- 
tomized: the parietal bones, where they first unite 
with one another, namely, about the middle third of the 
interparietal margin, exhibit dentations of a character 
different from those at the anterior and posterior 
thirds. At the anterior third they are not pronounced, 
and may be absent; at the posterior they are narrow 
and long.-The parietal bones unite with the frontal 
at the middle third of each half of the frontal bone, 
the upper and lower third presenting less coarse den- 
tations. The dentations often end abruptly at the 
intersection of the coronal suture with the upper mar- 
gin of the temporal fossa, the coronal suture below 
this point being, as a rule, sinuate or straight. The 
lambdoidal suture is coarsely dentate throughout. 
From the above it appears that the sutures are 
dentate in a degree proportionate to the places at 
which contact first occurred. In the region of the 
fontanelles (see succeeding section) the sutures are 
nearly straight or harmonic.-In the negro the denta- 
tions are less prominently developed than in other 
races. 
The Fontanelles and Disappearance of the 
Sutures.-The fontanelles are the spaces between 
the incomplete angles of the cranial bones. They are 
occupied by membrane, which gradually becomes os- 
sified as development advances. The fontanelles are 
four in number, and are formed in part by the four 
angles of each parietal bone. They are named the 
median and the lateral fontanelles. The anterior me- 
dian fontanelle, or great fontanelle, lies between the 
antero-superior portions of the parietal bones and the 
halves of the frontal. It is of a lozenge or spear-head 
shape, and continues by its angles with the sagittal, 
coronal, and frontal sutural interspaces. It is the 
largest of the fontanelles. It disappears from the 
tenth to the fifteenth month, holding in this respect 
a close relation with the rapidity of the development 
of the entire osseous system. In a quickly closing 
fontanelle the teeth appear soon, and the child walks 
early. In cases of retarded development, on the other 
hand, the fontanelle remains open and larger, and in- 
deed, though this is rare, it may persist through life.- 
The posterior median fontanelle is placed between the 
postero-superior angles of the parietal bones and the oc- 
cipital angle. It is triangular in shape, and continuous 
with the lambdoidal and interparietal (sagittal) sutural 
interspaces. It is closed at birth or a few months 
after.-The lateral fontanelles lie at the antero-inferior THE SKULL. 
147 
and at the postero-inferior angles of each of the parietal 
bones and the adjacent parts. They are small, unim- 
portant, and disappear at birth. The hinder angle of 
the posterior lateral fontanelle is continuous with the 
interval between the divisions of the ascending por- 
tion of the occipital bone. Hyrtl records four instances 
in the adult skull of the persistence of a fissure an- 
swering in position to this angle. It is a striking fact 
that hernia of the brain never occurs through the 
fontanelles. 
At birth the sutures of the vertex are so imper- 
fectly formed that the bones can be made to slide 
slightly upon one another under moderate compres- 
sion without injury to themselves or to the brain be- 
neath. Such compression is inevitable during the 
delivery of the child, and is liable to take place to a 
greater or less extent during infancy. Post-mortem 
changes go on more rapidly in the brain when the 
fontanelles remain open than after they are closed. 
This fact is of medico-legal significance.1 The protec- 
tion secured to the sutures of the side of the skull 
appears to favor their early obliteration. Thus the 
coronal suture may be no longer traceable in the tem- 
poral fossa while yet distinct on the vertex. The 
sutures holding the temporal bone in position seem 
to disappear later than other cranial sutures, probably 
owing to the less pronounced organic union of this 
bone with the remaining cranial bones. 
The time at which the sutures disappear varies with 
the different bones, with race peculiarities, and, as has 
been noted, with the rate of activities of the general 
ossific development. This rate is less active in cold 
than in warm climates. Other things remaining the 
same, the sutures disappear in the order of the com- 
pletion of the development of adjacent parts. At fifty - 
five or sixty years, the sutures have become entirely 
obliterated. The sutures may separate under the 
distending force engendered by brain decomposition.2 
Universal union of the cranial sutures constitutes 
synostosis. Should one or more of the sutures close 
while the skull is yet growing, deformation occurs. 
This is probably a frequent cause of variation in the 
shape of the vertex. The sagittal suture prema- 
turely disappearing restrains the lateral expansion of 
the vertex, while forcing out the forehead and occi- 
put. A skull thus deformed is known as the scaphoid 
or boat-like skull. 
Premature sutural union is not of necessity evi- 
dence of the arrest of the development of the brain. 
Disappearance of the suture may result from exces- 
sive precocity of the osseous system, without any co- 
relation existing between the growth of the brain and 
that of the skull. A distinct class of symptoms arises 
when the brain continues its growth within an un- 
yielding brain-case, which is recognized by clinical 
writers. 
The effect of a prematurely united suture upon the 
general nutrition of the bones adjacent to it is decided. 
The edges entering into the sutural line are thickened, 
while the substance of the bone a little distance from 
the line is thinned, and, in rare instances, is even per- 
forated (see Parietal and Occipital Bones). 
The deformities of hydrocephalus are largely de- 
termined by the condition of the sutures at the time 
of the occurrence of the disease. Fixation at the line 
of the sagittal suture causes bulging at the forehead 
and the occiput. Fixation at both the lambdoidal 
and the sagittal sutures causes vertical bulging at the 
line of the coronal suture, and enormous increase of 
the ascending portion of the frontal bone. Should 
the intra-cranial pressure announce itself prior to the 
closure of any of the sutures of the vertex, the several 
bone£ composing it become widely separated, and the 
fontanelles enormously increased in size.1 
The bones of the vertex, arising as they do from 
membranous expansions, present a group of variations 
distinct from those that arise from cartilage. Prof. 
Turner2 endeavors to account for this by stating that 
the areas of the different bones are less precisely de- 
fined, and that the process of ossification is more liable 
to disturbance in the former than in the latter. The 
modifications in arrangement are especially apt to 
occur along the lines of apposition of adjacent osseous 
areas, as, for example, along the sutural lines, or along 
the margins of the subdivisions of a bone proceeding 
from distinct centres. 
The Wormian Bones (ossa triquetra).- The Wor- 
mian bones arc variable in shape, number, and 
position. They are seen, in order of frequency, be- 
tween the occipital and the parietal bones, at the 
junction of bones at the anterior third of the temporal 
fossa (pterion), and at the regions of the fontanelles. 
They are rare in the face, and are here almost con- 
fined to the roof and median surfaces of the orbit. 
They are unknown in the cranio-basic axis. It will 
thus be seen that the Wormian bones answer to the 
position of the membranous expansions, as opposed to 
> Rudolphi, Berlin. Abhandl. (Phys.), 1824, 121, figs. ; also J. 
von d. Hoeven, Acad. Caes. Leap. Nova Acta, xxix. 1862, figs. 
2 Edinburgh Royal Soc. Proc., v., 1866, 444. 
1 Casper, I. 46, Syd. Soc. edition. 
2 Casper, 1. c. i. 40. 148 
THE BONES 
the cartilaginous, and to the concave walls of extend- 
ing spaces. They are, indeed, detached centres of 
ossification in the marginal area of growing membrane 
bones, which-they aid in occupying intervening spaces 
among the bones themselves. They of necessity fol- 
low the rule of symmetry. 
Portal alludes to the fact that the Wormian bones 
have been depressed in injuries of the skull, and have 
resembled fragments of bone pressing against the 
meninges. Sauceratte1 reports a striking instance of 
error in diagnosis dependent upon mistaking the edge 
of a Wormian bone for a line of fracture. A tre- 
phine was about to be applied to the presumedly 
fractured point when the error was detected. 
The Cranial Base.-The base of the skull pre- 
sents two surfaces for examination-an interior and 
an exterior surface. 
The interior base of the skull (fig. 1, Plate XXIII.; 
fig. 3, Plate XXIV.) is divided into three sections, 
which comprise the anterior, middle, and posterior 
cerebral fossae. 
The anterior cerebral fossa is composed of the hori- 
zontal plate of the ethmoid bone, and the body ©f the 
sphenoid bone in advance of the olivary body. At 
the sides lie the orbital plates of the frontal and the 
lesser wings of the sphenoid bone. The floor is thin 
and compact, slightly convex over the orbits, and con- 
cave for the olfactory grooves. It is pierced by the 
foramen caecum, by the openings for the olfactory 
nerves, and by the optic foramen. It contains the 
anterior cerebral lobes and arteries, the olfactory 
tracts and bulbs, and the optic chiasm. 
The middle cerebral fossa presents in the cranial 
axis the pituitary fossa and the clinoid plate; late- 
rally, the great wing of the sphenoid and the squa- 
mous bone compose it. It is defined anteriorly by the 
lesser wing, and behind by the anterior aspect of the 
petrous bone. It presents everywhere a concave sur- 
face ; is irregularly marked with a number of digi- 
tate depressions; is thinned at the eminence corre- 
spending to the glenoid fossa, and at a point a little 
in advande of the foramen ovale; is pierced by the 
anterior lacerated foramen, the oval foramen, the 
spinous foramen, the hiatus Fallopii, and the termi- 
nation of the carotid canal; and accommodates the 
middle cerebral lobe, the Gasserian ganglion, and the 
encranial divisions of the primal branches of the fifth 
pair of nerves. 
The posterior cerebral fossa includes the following 
parts : At the middle line is seen the cranio-basic axis 
as far as and inclusive of the posterior«clinoid processes. 
Behind this axis lies the foramen magnum, and beyond 
this in turn lie the internal occipital protuberance 
and the line extending thence to the foramen mag- 
num. At the side, the posterior aspect of the petrous 
portion of the temporal bone and the related mastoid 
portion are seen. The posterior cerebral fossa is 
marked by the jugular eminence, and by the lateral 
groove for the sinus of the same name. The skull is 
very thick at parts answering to the base of the lateral 
sinus on the occipital bone. The posterior cerebral 
fossa is pierced by the foramen magnum, by the hypo- 
glossal canal, by the posterior lacerated foramen, by 
the internal auditory meatus, and by the mastoid fora- 
men. It contains the medulla oblongata, the cerebel- 
lum, the basilar artery, and encranial portions of the 
cranial nerves from the third to the twelfth. That 
portion of the posterior cerebral fossa lying below the 
groove for the lateral sinus on the occipital bone may 
be called the cerebellar fossa. 
The interior base of the skull conforms more nearly 
to the shape of the base of the brain than does the 
vault to its related brain surface. Injuries to the 
head may cause direct concussion and laceration from 
the violent contact of the brain against the interior 
base. According to Hilton,1 when the blow is received 
at the posterior part of the skull, the whole mass of 
the brain being driven forwards from the momentum 
given to it by the blow upon the bones of the skull, 
the under surface of the anterior part of the brain 
rubs over the depressed and elevated surfaces which 
1 Melange de Chirurgie, ii. 262. 
1 Lectures on Rest and Pain, 25. 
EXPLANATION OF PLATE XXII 
Fig. 1. The skull, seen from in front. 
Fig. 2. The nasal bone, seen from in front. 
Fig. 3. The nasal bone, seen from behind 
Fig. 4. The skull, seen from the side. PLATE XXII 
Fig. 2 
Fig. 3 
F^l 
Fig. 4 
T. Sinclair & Son.Lith. THE SKULL. 
149 
constitute the anatomical features of the internal base 
of the skull. 
The exterior base is the exterior of the parts form- 
ing the interior base. It is that surface remaining 
after the face has been removed. Anteriorly at the 
base of the forehead it is angulated to answer to the 
difference in level between the anterior and the middle 
cerebral fossae of the interior base. The horizontal 
plates of the frontal bones and the cribriform plate of 
the ethmoid bone form one line of the angle, and 
the anterior (orbital) surfaces of the greater wings of 
the sphenoid bone the other. At the inferior border 
of the latter, namely, at the superior border of the 
spheno-maxillary fissure of either side, an imagi- 
nary line drawn backward to the posterior border 
of the foramen magnum (opisthon), and thence to 
the external occipital protuberance, completes the 
limitation of the exterior base. The figure resultant 
upon the union of these lines may be compared to a 
letter Z, the lower horizontal member of which is 
greatly prolonged. In a less exact manner a line ex- 
tending from the external occipital protuberance to the 
fronto-nasal suture has been said to define the base. 
A section made by removing the parts intervening 
between the lower limb of the Z and the free anterior 
end of the figure would pass through the roots o.f the 
pterygoid processes, the angular processes of the fron- 
tal bones, the vomer, and the perpendicular plate and 
ossa plana of the ethmoid bone. 
Examined in detail, the exterior base of the skull 
presents for examination from before backward the 
following surfaces: The narrow and perforated crib- 
riform plate of the ethmoid bone; the horizontal 
plates of the frontal, which are thin, brittle, and 
slightly arched, together with the orbital surfaces of 
the lesser sphenoidal wings; the section of the exter- 
nal angular process, showing spongy tissue; the smooth 
surface of the thick, spongy greater wing of the sphe- 
noid bone-the junction of the horizontal and sphenoid 
surfaces, which is often marked by a number of minute 
foramina. Behind this region the body of the sphe- 
noid bone, the bases of the pterygoid processes, the 
horizontal limb of the greater wing of the sphenoid, and 
the squamous portion of the temporal bone, are seen. 
Yet more posteriorly lies the cranio-basic axis, as 
here represented by the basilar portion of the occipital 
bone. The lateral portions are composed of the under 
surface of the petrous portions of the temporal bones 
and of the tympanic bones. The posterior basal sur- 
face is made up of the foramen magnum, of the oc- 
cipital condyles, of the lateral portion of the occipital 
bone, and of the ascending portion of the same as far 
as the superior semicircular line. 
The exterior base of the skull is marked by the 
lateral processes of the frontal bone, by the pterygoid, 
the spinous, styloid, mastoid, and jugular processes, and 
by the occipital condyles. It presents for examination 
the following fossm: the pterygoid, scaphoid, glenoid, 
digastric, and the depressions in front and behind the 
occipital condyles. 
The exterior base is pierced by the optic, anterior 
lacerated, oval, spinous, and posterior condyloid fora- 
mina. It receives the termination of the hypoglossal 
canal and the beginning of the carotid canal. 
The structure and openings defined by the union of 
parts entering into the exterior base are: First, the 
anterior lacerated foramen between the greater and 
lesser wings of the sphenoid bone. It looks directly 
forward. Secondly, the Eustachian sulcus-extending 
inward and forward from the inner end of the glenoidal 
fissure to the body of the sphenoid bone. It is formed 
in part by the sphenoid and in part by the petrous 
portion. Its base is often incomplete. Thirdly, the 
median lacerated foramen; this is an interval between 
the tip of the petrous portion and the body of the 
sphenoid bone. It is occupied by fibro-cartilage 
during life. It is of variable size, and in the long and 
narrow skulls, as the skull of the negro, may be absent. 
Fourthly, the petro- basilar groove. This is a depression 
lying between the petrous portion and the outer side 
of the basilar process. It is filled with fibrous tissue 
during life, and is continuous with that filling up the 
median lacerated foramen.1 Fifthly, the posterior lace- 
rated foramen. This is formed by the union of the 
jugular grooves of the petrous portion of the tempo- 
ral and the jugular groove of the occipital. It 
transmits the jugular vein, and the ninth, tenth, and 
eleventh cranial nerves. A bony septum (inter-jugu- 
lar process, Henle) often separates the nerves from the 
nerve veins. 
The posterior lacerated foramina and the jugular 
fossae vary greatly in size in different individuals, and 
on opposite sides of the same individual.2 A num- 
ber of hypotheses have been from time to time an- 
nounced according to which a definite connection be- 
tween the size of the foramina and the activity of the 
brain centres and the special organs is traced. It 
has been claimed3 that the foramina are contracted in 
1 The median lacerated foramen is not to be confounded with the 
termination of the carotid canal seen within the middle cerebral 
fossa. 
2 Theile, Zeitschr. fiir Rationelle Medicin, 1855, 339 ; F. 0. Ward, 
Outlines of Human Osteology, 58 ; T. Dwight, Am. Journ. of Med. 
Sci., Oct. 1873 ; Riidinger, Monatsch. fiir Ohrenheilkunde, 1875. 
3 Kasloff Oppenheim. Zeitschr. fiir die gesammte Med., Jan. 1844 
-abstract in Amer. Journ. of Med. Sci., 1844, 209, vol. viii. 150 
THE BONES 
maniacs and in suicides; and that subjective noises 
in the ears are at times associated with a narrowed 
foramen, especially when a wide bulbus of the jugu- 
lar vein exists. An eddying current of blood is 
hereby created, it is thought, the sound of which is 
conducted to the labyrinth.1 
The carotid canal is defined only when the bones 
are articulated. The inferior orifice is confined en- 
tirely to the petrous portion of the temporal bone. 
The superior orifice lies above the petro-basilar fissures 
at the middle lacerated foramen, as seen upon the in- 
terior base. 
The base of the skull, as has been seen from the 
foregoing, will have connection with the face through 
the horizontal plate of the frontal bone, with the 
pharynx through the basilar portion of the occipital 
and the body of the sphenoid bone, and with the neck 
in the region behind the foramen magnum. 
The base has been di vided by writers on topographi- 
cal anatomy by regions answering measurably to the 
above subdivision. Thus the palatal or facial-gut- 
tural or pharyngeal and occipital portions are de- 
scribed. But in practice little or.no advantage accrues 
from following such an arrangement of parts. In 
seeking for the lesions of fracture, it is true, the base 
may be considered as a whole, but for all other clinical 
purposes it is best to ignore it. The palatal region 
is included in the face; the occipital becomes post- 
atlantal, and is included in the region of the neck. 
The so-called guttural region forms the base of the 
skull as distinguished from the adjacent regions. 
Clinically restricted, when a tumor is stated as 
having its origin at the base of the skull, that por- 
tion immediately above the pharynx is intended. 
For the location of disease at the base of the skull 
the following division will be found worthy of con- 
sideration. By connecting the apices of the mastoid 
processes a line will be described which traverses 
each of the occipital condyles at its middle. This 
line will include the points of insertion of the muscles 
turning the head, as well as the region of the fulcrum 
at which the motion occurs. Behind and in front 
of this line lie the muscles which bow and retract the 
head. It therefore represents a region to be specially 
studied in all cases in which impairment of motion 
of the head or of the neck is a conspicuous sign. A 
second line extending forward from the digastric 
groove of the mastoid process to the inner plate of 
the pterygoid process will lie directly to the inner 
side of the oblique line of processes-the styloid, vagi- 
nal, spinous-and will retain all the foramina. Thus 
the jugular foramen and the beginning of the carotid 
canal lie directly upon the line, while the spinous and 
oval foramina lie immediately to the outer side. This 
line divides the under surface of the petrous portion 
of the temporal bone into two natural parts; the part 
to the lateral side of the line is related to the front 
'of the neck and the face; that to the median side 
is connected with the pharynx. A tumor located 
at the lateral side of the line would involve the 
cheek-tissue, and in all likelihood be excluded from 
the base of the skull by the recorder. One arising 
from the median side would be as certainly described 
as connected with the base of the skull. 
The Sutures of the Base.-The sutures of the 
base include the cranio-facial sutures; the squamoso- 
sphenoidal is seen traversing the zygomatic fossa ; this 
division of the squamoso-sphenoidal suture is observed 
to be continuous with the squamoso-tympanic suture at 
the glenoidal fissure; in the median line is the basilo- 
sphenoidal suture. The straight, non-serrate petroso- 
sphenoidal suture lies at the bottom of the sul- 
cus for the cartilaginous portion of the Eustachian 
tube. .Next in order is the petroso-basiar suture at the 
bottom of the groove of the same name. It is a nearly 
straight, smooth junction. The horizontal limb of the 
occipito-mastoid suture is next seen. It is a nearly 
straight sutural line extending from about the centre 
of the digastric groove to the posterior lacerated 
foramen. 
Structure.-In the occipital bone between the 
condyles and the jugular processes, in the petrous por- 
tion of the temporal bone in great part, and in the 
horizontal portion of the greater wings of the sphe- 
noid the base of the skull is compact. It is spongy in 
the occipital condyles, in the basilar processes, in the 
pterygoid processes in great part, and in the jugular 
and the mastoid processes. The last two processes, 
together with the posterior projection from the base 
of the pterygoid processes bordering upon the middle 
lacerated foramen, are noticeable for the coarseness of 
the interspaces. 
In fractures of the skull, the under surface of the 
frontal lobes of the brain and the rounded end of 
the spheno-temporal lobes are often found torn and 
bruised, even when the lines of fracture do not corre- 
spond to the seats of brain-lesion. This is not likely 
to occur under the cerebellum or pons, owing to the 
large lymph-cavities there present. 
1 S. Moos, Archiv of Ophth. and Otol., v. 478. THE SKULL. 
151 
Remarks.-For all practical purposes, the basilar 
process and the body of the sphenoid bone form -one 
structure, which may be called the cranio-basic axis. 
The spongy tissue here situate is often the seat of 
ostitis. It is found by surgical writers to be liable to 
caries, particularly that portion of it composing the 
body of the sphenoid bone. Caries originating in this 
locality will often involve the nasal chamber and ex- 
cite inflammation of the pharynx, into which chamber 
particles of bone may be discharged. 
Disease rarely attacks both base and vault in the 
same subject. If the vault is involved, the base es- 
capes, and vice versa. 
Pressure exerted from the accumulation of fluid in 
the descending horn of the lateral ventricle, as from 
hydrocephalus, creates distortion of the sides of the 
middle cerebral fossa, and, if the condition of the 
sutures permit, rotation of the temporal bone out- 
ward and downward, with resultant deformation of 
the basis of the skull and the side of the face. In 
such cases the external meatus lies on the base of the 
skull close to the occipital condyles, and a lateral 
pouch encroaches upon the sides of the face.1 
In cretinism the deformations are in their initial 
forms basal, and pertain to errors of development and 
trophic change in the bones arising from cartilage at 
the cranio-basic axis. The cancellated structure of 
the basilar process of the occipital bone is exaggerated; 
the sphenoidal sinus is enlarged or malformed; the 
dorsum sellse is steep; and the inclination of the 
plane of the basi-axis is variously changed from the 
normal-plane. Accessory to these deviations, and in 
a measure dependent on them, ensue modified facial 
proportions and dental irregularity.2 
THE CRANIO-FACIAL, OR INTERMEDIATE PORTION 
OF THE SKULL. 
The union of the cranium and the face is effected 
at four places: at the zygoma, at the junction of the 
malar and temporal bones; at the outer wall of the 
orbit, at the junction of the frontal and malar bones; at 
the pterygo-maxillary junction, between the superior 
maxilla, palatal, and sphenoid bones; and finally at 
the junction between the vomer, the perpendicular 
plate of the ethmoid bone, and the bones articulating 
therewith (figs. 1 and 2, Plate XXIV.). Resulting 
from these lines of union a region is imperfectly 
defined on the exterior base of the skull, which may 
receive the name of the cranio-facial region, since 
its parts cannot be defined without including bones 
common to both the cranium and the face. 
This region lies medianly to the zygomatic arch, 
and embraces two fossse, the zygomatic fossa and the 
spheno-maxillary space (fig. 1, Plate XXIV.); and two 
fissures, the ptery go-maxillary and the spheno-maxil- 
lary. 
The zygomatic fossa is bounded in front by a line 
produced downward from the under free border of the 
malar process of the superior maxilla; behind by the 
posterior free edge of the external pterygoid plate; 
below by the alveolar process posterior to the second 
molar tooth ; and above by the ridge separating the 
Temporal from the External Pterygoid muscles. The 
bottom of the fossa is composed of the tuberosity of 
the superior maxilla, and the outer surface of the ex- 
ternal pterygoid plate. Above it admits the hori- 
zontal portion of the greater wing of the sphenoid 
bone. It is continuous above with the temporal fossa 
and the orbit; behind with the exterior base of the 
skull; below, when the lower jaw is in position, with 
the parts about the coronoid process of the lower 
jaw ; and medianly with the spheno-maxillary space. 
The spheno-maxillary space (spheno-maxillary fossa) 
is the space between the free anterior surface of the 
upper half of the pterygoid process behind; the 
median part of the tuberosity of the superior maxilla, 
and a small portion of the orbital process of the 
palatal bone in front; and the outer wall of the nasal 
chamber (where it is defined by the thin and weak 
vertical plate of the palatal bone) within. The space 
has the form of a narrow triangle whose base is 
upward, where it is continuous with the orbit at the 
posterior end of the spheno-maxillary fissure. It is 
thus limited above by the spheno-maxillary fissure; 
while the pterygo-maxillary fissure limits it laterallv. 
While the two last-named fissures aid in limiting the 
space, they serve as means of communication with the 
orbit and zygomatic fossae respectively. The median 
surface or floor of the space joins the nasal chamber 
by means of the spheno-palatine foramen. 
The spheno-maxillary fissure results from the for- 
mation of the orbito-temporal septum. It has no 
existence in animals in which the orbit and temporal 
fossae are continuous, as in the dog and the lower 
animals generally. 
At the base of the skull the position of the cranio- 
facial portion is indicated by the junction of the vomer 
with the body of the sphenoid. Clinical writers 
recognize that the relations of the rostrum of the 
1 Prescott Hewett, St. George's Hosp. Rep., i., 1866, 25, figs. 
2 F. V. Zillner, Nova Acta, 1. c., xxvii., with figures ; R. Vir- 
chow, Untersuchungen fiber die Entwickelung des Schadelgrundes, 
1857. 152 
THE BONES. 
sphenoid are with the pharynx, while those of the 
ethmoid spine are with the nasal chamber. Indeed, 
the anterior surface of the body of the sphenoid, in- 
cluding the sphenoidal sinuses, is as much facial in 
its relations as it is cranial. 
Remarks.-The spheno-maxillary space will readi- 
ly receive prolongations of tumors originating in the 
nasal fossa after the thin vertical plate of the palatal 
bone has been absorbed. Nasal polyp has been de- 
scribed as thus disposed; and Greco1 has discovered 
a multiple form of morbid growth of obscure origin 
passing in the manner described from the nasal cham- 
ber to this space. 
Mr. Prescott Hewett2 describes a tumor growing 
from the exterior base of the skull that pushed its way 
through the spheno-palatine foramen into the spheno- 
maxillary space, and thence through the pterygo- 
maxillary fissure into the zygomatic fossa, and by this 
region round the zygomatic surface of the superior 
maxilla to appear upon the cheek. A specimen is 
preserved in Guy's Hospital, London, of a cartilagi- 
nous tumor at the base of the skull, which had 
advanced into the zygomatic and spheno-maxillary 
space. It had involved the orbits, nasal chambers, 
and the maxillary sinuses. 
Langenbeck3 diagnosed a fibroid tumor originating 
in the spheno-maxillary space, which involved the 
nasal chamber and naso-pharynx by passing medianly 
through the enlarged spheno-palatine foramen. The 
nasal septum was deflected to the right, and the left 
choana was obstructed. The mass also extended 
laterally to invade the zygomatic fossa, and superiorly 
to enter the orbit and to press the eye outward. In 
an operation for the removal of the tumor the parts 
were found enlarged to three times their normal 
size. 
A small but noticeable crest is frequently seen on 
either side of the vomer, which aids in defining the 
posterior nares. This crest sometimes extends across 
the upper arc of the posterior nares so as to rest upon 
the sphenoidal process of the palatal bone. This out- 
growth may receive the name of the vomerine crest. It 
serves to separate the roof of the pharynx from the 
cavity of the nose. Specimens have been met with 
in which the crest has shown evidences of thickening 
from inflammation. 
THE FACE. 
The face (figs. 1 and 4, Plate XXII.) is that portion 
of the skull designed to protect the eyes, the nose, 
and the teeth, and in connection with the latter to 
define the osseous parts entering into the construction 
of the mouth. 
The face is of a triangular figure. One of the sides 
answers to the exterior base of the skull in advance 
of the external auditory meatus, and may be called 
the superior border. Another extends from the upper 
margin of the orbits to the lower margin of the infe- 
rior maxilla, and constitutes the anterior border or 
surface. The remaining border of the figure is the 
inferior, and is defined by the lower margin of the 
inferior maxilla. 
The Orbits.-The orbits are two conical cavities 
lodged for the most part in the face, but defined in 
part by the bones of the brain-case, and designed to 
accommodate the eyeball and accessory parts. Each 
orbit presents for examination a median (inner), and 
a lateral (outer), wall, a roof, and a floor.-The median 
(inner) wall is nearly straight, but slopes a little out- 
ward as it joins the floor. It is composed of the os 
planum of the ethmoid bone, and of the lateral surface 
of the lachrymal bone.-The lateral (outer) wall is more 
obliquely placed to the median line of the face than 
is the inner. It is composed in great part of the or- 
bital surface of the greater wing of the sphenoid 
bone. In advance of this surface lies the frontal pro- 
cess of the malar bone. The outer wall is defined in- 
feriorly in part by the sphend maxillary fissure.-The 
roof of the orbit is slightly concave'. It is composed 
of the orbital plate of the frontal bone, excepting at 
its apex, where a small portion of the lesser wing of 
the sphenoid bone is lodged.-The floor of the orbit is 
continuous with the median wall, but separated from 
1 Archiv. de Med., xxiii. 431. 
2 Med.-Chir. Trans., xxxiv. 47. 
3 Deutsche Klinik., 1861 ; also, Med. Times and Gazette, 1861 
(abstract). 
EXPLANATION OF PLATE XXIII. 
Fig. 1. The skull, seen from beneath (exterior base). 
| Fig. 2. The base of the skull, seen from within (interior base). PLATE XXII 
Fi § ■ 2. 
Fig 
Sinclair & Sen.lift. THE SKULL. 
153 
the lateral wall the greater part of its length by the 
spheno-maxillary fissure. In front the floor is com- 
pleted by the malar bone, and behind by the orbital 
process of the palatal bone. 
The orbit communicates with the cranial cavity by 
the optic foramen and the anterior lacerated foramen. 
The optic foramen lies at the apex of the orbit at the 
junction of the median wall and the roof. The ante- 
rior lacerated foramen extends from the median wall 
obliquely outward and inward along the junction of 
the lateral wall and the roof.-The orbit communicates 
with the temporal fossa through the spheno-maxillary 
fissure. The anterior and the posterior ethmoidal fora- 
men are found at the junction of the median and late- 
ral walls. The anterior ethmoidal foramen transmits 
the anterior ethmoidal artery and the nasal nerve; 
the posterior ethmoidal foramen transmits the poste- 
rior ethmoidal artery. 
The Nasal Foss^;.-The nasal fossae (fig. 2, Plate 
XXIV.) are two irregular cavities, one on either side 
of the septum. Each fossa is narrowed above, is 
higher before than behind, and presents for examina- 
tion a lateral and a median wall, a roof, a floor, and 
an anterior and a posterior aperture.-The lateral 
wall is exceedingly complicated. It is composed of 
processes of the nasal aspect of the lateral mass of the 
ethmoid bone, of the inferior turbinated bone, and of 
the nasal aspect of the body and the ascending process 
of the superior maxilla. The lateral wall is uneven by 
reason of the position of the superior and middle tur- 
binated bones (see the Ethmoid Bone, p. 131), as well 
as by the position of the inferior turbinated bone. 
The middle meatus is seen to be well defined between 
the lower margin of the middle turbinated bone and 
the upper margin of the inferior turbinated bone, 
and the inferior meatus, between the lower margin 
of the inferior turbinated bone and the floor of the 
nose. Under the term ay ger nasi, Meyer describes 
a crest extending from the upper margin of the mid- 
dle turbinated bone forward along the lateral wall. 
The median wall of the nasal chamber is the nasal sep- 
tum. It is composed of the following parts named in 
the order of their importance; the perpendicular plate 
of the ethmoid bone, the vomer, the maxillary and 
the palatal crests, and the frontal spine. The upper 
two-thirds of the inner wall is derived from the eth- 
moid bone. In the undissected subject the triangular 
cartilage completes the median wall anteriorly. Rarely 
if ever straight, the median wall inclines commonly to 
the left side at the vomero-ethmoidal junction. Oc- 
casionally it is incomplete. - The roof of the nasal 
chamber is very irregular. Anteriorly, i. e., in advance 
of the cribriform plate, it is oblique from before back- 
ward and from below upward, and is composed of the 
nasal bone and the spine of the frontal bone. The 
cribriform plate occupies the middle third of the roof 
or more. It is straight or slightly concave. The 
remaining portion of the roof is derived from the 
sphenoid bone.-The floor is shorter than the roof, 
and is composed of the upper surfaces of the hori- 
zontal plates of the superior maxilla and the palatal 
bone. It is inclined slightly from before backward, 
and the premaxillary portion is often elevated above 
the level of the remaining portion.- The anterior 
nasal aperture (anterior nares) is a pear-shaped open- 
ing defined below and at the sides by the superior 
maxillae, and above by the nasal bones. It thus 
forms the common opening to both nasal chambers.1 
Its plane is directed slightly obliquely from below 
upward and from behind forward. Its apex is on a 
level with the superior meatus and the sphenoidal 
sinus.-The posterior nasal aperture (posterior naris, 
choana) is smaller than the anterior by about one- 
fourth its height, and is defined without by the pterygo- 
palatine junction, within by the vomer, above by the 
vomerine crest (see p. 133) and the sphenoidal pro- 
cess of the palatal bone. The plane of the posterior 
nasal aperture is oblique from below upward and 
from before backward. 
Each nasal chamber, in addition to the communi- 
cation already mentioned, joins the orbit by the 
ductus ad nasum, the zygomatic fossa by the spheno- 
palatine foramen, and the brain-case by the foramina 
of the cribriform plate. It receives the outlet from 
the maxillary, frontal, and the sphenoidal sinuses, as 
well as the ethmoid cells. 
For clinical purposes, the nasal fossae are capable 
of being divided into three portions: the premaxil- 
lary, the maxillary, and the palatal portions. These 
names are selected from the surfaces occupied by 
the bones entering into the composition of the 
hard palate and the lateral walls of the nasal fossae 
answering to the same. Thus, the premaxillary por- 
tion of the fossa lies in advance of the anterior palatal 
canal, and all the parts of the lateral wall in advance 
of the anterior border of the cribriform plate. The 
maxillary portion answers inferiorly to the surface 
between the anterior palatal canal and the suture 
between the -maxilla and the palatal bones on the 
hard palate, and superiorly to the posterior border of 
1 When it is intended to name the outlet of a single chamber, the 
term anterior naris or posterior naris is permissible. 154 
TIIE BONES 
the cribriform plate. The palatal portion lies be- 
tween this line and the plane of the posterior nares. 
The Hard Palate.-The hard palate (fig. 2, Plate 
XXIII.), or roof of the mouth, is composed of the 
palatal aspect of the premaxillae and the palatal plates 
of the superior maxillae and of the palatal bones. The 
hard palate is of a IT-shape, the limbs of the figure 
being slightly divergent. In the negro, the free 
hinder ends tend slightly to approach one another. 
The posterior free border is composed of two emar- 
ginate surfaces united at a median point, called the 
posterior palatal process or spine. The posterior 
palatal process may be absent when a triangular 
notch is seen in its place, or the two emarginations 
of the palatal bones are continuous with each other 
without interruption. The hard palate, when divided 
transversely (frontal section), exhibits the form of an 
arch, of which the pillars are constituted by the 
alveolar processes, and the top by the parts above 
named. At the median line, the hard palate behind 
the premaxillary portion is thicker than elsewhere. 
Occasionally a pronounced median swelling or flat 
ridge is seen, which forms a conspicuous projection, 
detectable with ease even in the living subject. On 
either side of the median ridge- the hard palate is 
thin, and may be diaphanous. At the junction of the 
hard palate with the alveolar process a conspicuous 
longitudinal groove is seen for the accommodation of 
the palatine arteries and nerves. The hard palate is 
pierced anteriorly by the incisorial foramen so called. 
To speak accurately, two incisorial foramina, situated 
one on either side of the nasal septum, so far unite 
as to present but a single opening upon the hard 
palate. Each foramen transmits the anterior palatal 
branch of the superior maxillary nerve, as well as a 
small artery, the anterior palatine of its own side. 
Near the posterior border and at the base of the alve- 
olar process, is the posterior palatal foramen for the 
posterior palatal artery and nerve. This foramen is 
protected in a measure by adjacent rugosities, and 
bv a strong buttress-like ridge of the palatal bone. 
The hamular processes of the sphenoid bone can be 
readily felt in the living subject by passing the finger 
back of the wisdom tooth a little to the median side 
of the alveolar process. They serve as guides to the 
posterior limitation of the hard palate. 
The Inter-orbital Space. - The inter-orbital 
space includes the nasal bones, the ascending pro- 
cesses of the superior maxillas, the frontal bone below 
the level of the supra-orbital arches, and the lachry- 
mal bone as far as the lachrymal crest. The ductus 
ad nasum thus pertains to the superficies of the face 
rather than to the orbit. The conjunction of the 
frontal and nasal bones and the ascending processes 
of the superior maxillae in this space is such that 
enormous strength for resisting pressure and sustain- 
ing weights results. Fracture, or other injury, is rare 
here. Yet the lower half of the nasal bone is not 
infrequently either fractured or displaced. Ivory 
exostoses, for some unexplained reason, arise occa- 
sionally from the line of union of this space with the 
orbit.1 
At a superficial glance, the modifications of the 
face, in order to accommodate the teeth, are restricted 
to the alveoli. But a more careful examination will 
show that the entire facial region is adapted to the 
forces employed in using the teeth. It has been 
seen that the bones of the face, with the excep- 
tion of the lower jaw, are immovably united to one 
another and to the brain-case. To raise the lower 
jaw and to bring it against the upper so as to make 
these acts efficient in the seizing, the cutting, and the 
grinding of food, demand, on the part of the last- 
named structure, a power of so conducting the forces 
of occlusion as to avoid concussion of the delicate 
structures contained in the orbits and nasal fossae. 
The act of seizing and tearing food appears to de- 
mand greater strength than that of cutting or grinding 
it. The stout canine tooth conveys the shock along 
1 Consult Duka, Trans. Path. Soc. London, xvii., 256 ; also 
W. Watson, Ibid., 1868, xix., 310. 
EXPLANATION OF PLATE XXIV. 
Fig. 1. Skull, seen from the side, exhibiting the profile view 
of the base ; method of union of the bones of the brain- 
case and the face ; together with the composition of the 
median wall of the maxillary sinus. 
Fig. 2. Sagittal section of skull ; the lower jaw and skull- 
cap are removed. 
Fig. 3. The lateral region of the exterior base of the skull, 
slightly enlarged. PL ATE XXIV 
Fig .1. 
Fi g. 2 
Fig. 3 
T 5mcTan & Son,Inti, THE SKULL. 
155 
the canine eminence to the ascending process of the 
superior maxilla, and thence it is received and dis- 
tributed by the frontal bone to the cranial vault. 
The act of grinding demands a wide surface. This 
is secured by the divergent roots of the molar teeth, 
through which the force of the occlusion is diffused, 
and by the malar process, which conducts and dis- 
tributes the shock to the zygoma and the cranial 
vault. The act of cutting demands little osseous sup- 
port, and is accomplished entirely by the scissor-like 
action of the upper and the lower incisors against each 
other. The direct apposition of these teeth produces 
a decidedly unpleasant sensation. Disease and even 
death of the incisors may result from the habit (so 
common among seamstresses) of employing the incisor 
teeth in the position just named to bite off threads. 
From the lines of conduction and resistance just 
mentioned, it is evident that there exist in the face 
two lines adapted to the conduction of shocks: one 
leading from the canine eminence through the ascend- 
ing process of the superior maxilla, and therother from 
the malar process of the same bone to the malar bone. 
The spaces inclosed between the canine teeth, and 
between each canine tooth and the malar process of 
the corresponding side and the malar bones, are not 
adapted to convey or resist shock. It is within these 
spaces that the eyes and nasal organs are placed, and 
the nerves and bloodvessels lie. Even in the lower 
jaw we find in the adult the mental foramen on the 
same vertical line with the infra-orbital and the supra- 
orbital foramina. The repeated occlusions of the 
lower jaw against the upper may be said to maintain 
the shape of the latter. When the lower jaw is re- 
moved the alveolar processes fall inward, notwith- 
standing that the hard palate remains intact. This 
is well illustrated in a case reported by Bibes1 of gun- 
shot wound of the lower part of the face in which the 
lower jaw was torn away. 
In extensive lesions of the face in which the lines 
of attachment between the immobile portion of the 
face and the brain-case have been severed, and yet the 
soft parts have been retained intact, the act of chew- 
ing becomes impracticable. The writer observed the 
case of a man who had incurred multiple fracture of 
the region of the face from a premature explosion of 
a blast: recovery from the immediate effects of the 
injury followed, but with absence of union between 
the face and the brain-case. The entire "upper jaw" 
was freely movable. The patient was sustained 
by liquid food. Dr. Fyffe2 reports a case of disloca- 
tion of the bones of the face with fracture, including 
marked movability of the upper jaw during degluti- 
tion. 
Surgical writers include in the term superior max- 
illa, or "upper jaw," parts embracing the palatal, infe- 
rior turbinate, and part of the ethmoid and the malar 
bones. The bones named are of necessity removed 
in the operation for excision of the superior maxilla. 
Viewed in this way the superior maxilla is said to 
be included between the inter-orbital space, the face 
as far laterally as the outer wall of the orbit, and the 
hard palate including the junction with the pterygoid 
process. The last-named junction is apt to be re- 
tained after complete severance at the other parts- 
and forcible depression of the partially detached mass 
is necessary before the final division can be effected. 
Abernethy mentions a case in which the bones of 
the face were torn away from the skull, and left hang- 
ing merely by the optic nerves. 
THE STRUCTURE OF THE SKULL CONSIDERED WITH 
SPECIAL REFERENCE TO THE EFFECTS OF INJURY. 
The effects of injury upon the skull are varied by 
many circumstances, chief among which are the fol- 
lowing :- 
(1) The distribution of the spongy and compact 
tissue. 
(2) The disposition of the cranial bones and their 
sutures. 
(3) The direction from which the blow is received, 
as well as the position of the head at the time. 
(1) The Distribution of Spongy and Compact Tissue. 
-The cranial vault is composed for the most part of 
spongy tissue overlying a thin compact layer. The 
spongy tissue is best developed at the occiput and 
at the sides of the vault. The squamae, the sutural 
lines, the depressions for the Pacchionian bodies, and 
the forehead below the frontal eminences, are compara- 
tively devoid of it. This spongy tissue of the vault 
has received the name of diploe. It is described as 
occupying the interspace between two plates, the 
outer and inner. The last named of these alone is 
worthy of the name, since the first named is incon- 
stant in development, and may be absent. When 
present it is furnished with a number of minute open- 
ings for the escape of veins. The diploe is composed 
of a network defining irregular interspaces. These 
may assume a lamelliform arrangement, but are more 
frequently without apparent order. The diploic cells 
1 Diet, des Sciences Nat., 1818, xxix., 425. 
3 Lancet, 1863, ii., 64. 156 
THE BONES. 
are filled with a marrow-like substance, together with 
some free fat. Ramifying among them are the canals 
of the diploe for the veins of the same name. The 
spongy tissue throughout the rest of the brain-case 
preserves the same general characters as that of the 
vault. It is well developed at the following localities: 
in the occipital bone at the region of the occipital 
protuberance, and in the median line thence to near 
the foramen magnum in the occipital condyles and 
the under surface of me jugular process; in the mas- 
toid process; in the petrous portion of the temporal 
bone from the position of the posterior meatus to its 
tip ; in the axis of the cranium from near the anterior 
margin of the foramen magnum to the position of the 
sphenoidal sinus, inclusive of the posterior clinoid 
plate; in the great wings and the pedicle of the ex- 
ternal pterygoid plate of the sphenoid bone; and in 
the posterior pedicle of the lesser wing of the same 
name. In the facial region the spongy tissue is most 
conspicuous in the alveolar processes and the malar 
bones. 
Compact hone-tissue is seen in the vault at the inner 
plate, as already mentioned. This layer is thick and 
smooth. It nearly corresponds to the shape of the 
brain, and presents at the base of the anterior and the 
middle cerebral fossae a number of ridge-like eleva- 
tions, which serve to give the plate increased strength. 
At the cranio-basic axis the inner plate is thinner than 
the outer. In some forms of hypertrophy the inner 
layer of the skull is enormously thickened; on the 
other hand, it may become lost in an osteoporotic 
condition which extends entirely through the skull- 
wall. Among other localities, the compact tissue is 
noticeable in the petrous portion of the temporal 
bone ; in the cerebellar fossae, the glenoid fossae, the 
lesser wings and spinous processes of the sphenoid 
bone; and in the orbital plates of the frontal bone. 
Within the face all the bones entering into the nasal 
chamber and the walls of the maxillary sinus are 
papyraceous in consistence. In describing the course 
of the lines of fracture in the cranium, the character of 
the bone through which the fissures pass should receive 
the same attention as the direction of the fissures. 
(2) The Disposition of the Cranial Bones and their 
Sutures.-The arrangement of the cranial bones and 
their sutures holds an exact relation to the mechan- 
ics of the skull. The union of the parietals by the 
interparietal suture converts the two parietal bones 
into an arch, the abutments of which are formed by 
the antero-inferior and the postero-inferior angles of 
the bones. Between these abutments, on either side, 
is seen the squamosal emargination. The plan of 
articulation of the abutments is significant of their 
use. The posterior is received into a V-shaped interval 
at the ascending portion of the occipital bone, and the 
re-entering angle is formed between the squamous and 
the mastoid portions of the temporal bones-producing 
a conjunction of sutural lines named the stellion of 
Broca. At a short distance below this point lies the 
occipito-mastoid suture. The anterior pillar of the 
abutment is received upon the anterior portion of the 
squama, and the greater wing of the sphenoid bone at 
the so-called pterion of Broca. At the base of the skull, 
in the line of the anterior abutment, lies the squamoso- 
sphenoidal suture. Rarely, a separate suture exists 
at the conjunction of the horizontal and ascending 
portions of the greater wing. It will be thus seen 
that the abutments of the arch formed by the parietal 
bone through the junctions effected by its antero- 
inferior and the postcro-inferior angles rest upon parts 
of the base crossed by sutures. These sutures are 
harmonic, and are among the last to disappear. It is 
evident that a vibration passing from the vertex to 
the base by either of the abutments will be diffused 
by the time it reaches the base. From the position 
of the parietal bone with its slightly oblique direction 
from before backward and above downward, it would 
appear to facilitate the transmission of vibration along 
the posterior abutment. The distribution of the 
waves of vibration from both the anterior and poste- 
rior abutments to the face, the spongy tissue of the 
sphenoid, and the basilar process, is so effected as to 
protect the . brittle petrous portion of the temporal 
bone. It is well to recall the free, coarsely-cancellated 
projections already remarked upon the basal region 
-viz., the mastoid, jugular, and other processes-as 
structures well adapted to receive and diffuse vibra- 
tions. 
The sutures of the skull exert a marked influence 
in modifying injury during infancy and in youth. In 
adult life, the sutures may separate as the result of 
violent injury, but more commonly, particularly at 
that period at which the sutures have disappeared, 
the injuries occur in great measure entirely indepen- 
dently of the sutures. In individuals over fifty-five 
years of age, the study of fracture becomes one of di- 
rections of resistance and force without reference to 
the position of sutures. The fissures of fracture may 
even traverse large foramina. 
(3) (a) The Direction from winch a Blow is Received.- 
Fracture of the base of the skull will be found to cor- 
respond to the region of the vertex which has received THE SKULL. 
157 
the blow. Thus fracture of the orbital plate of the 
frontal bone may follow a blow on the vertex at the 
ascending portion of the same bone. To facilitate the 
study of lesions resulting from blows received on the 
vertex Prescott Hewett1 proposes a division of the 
skull into three segments or zones: an anterior zone 
formed by the frontal, the upper part of the ethmoid, 
and the wings of the sphenoid; a middle zone, by the 
parietals, the squamous, and the anterior surface of 
the petrous portions of the temporals, with the greater 
part of the body of the sphenoid bone; and a poste- 
rior zone, including the occipital, the mastoid, and the 
posterior surfaces of the petrous portions of the tem- 
porals, with a small part of the body of the sphenoid. 
-With the skull thus divided, the lines of fracture 
in the less severe cases are seen to be strictly limited 
to one or the other of these zones.-The region of 
the sphenoid bone, either alone or in combination with 
the other regions of the base, is that in which fracture 
most frequently occurs. Upon it the lines of conduc- 
tion from the parietal arch are converged. 
(6) The Position of the Head at the Time of the Recep- 
tion of the Blow.S^mQ of the vibrations of blows 
received upon the vertex the skull will conduct 
either through the cranio-basic axis or the vertebral 
column. The manner in which this is accomplished 
will vary according to the position of the head at the 
time of the reception of the blow. The occipital con- 
dyles rest upon the atlas, and it is seen that each con- 
dyle is placed obliquely to the base of the skull, and 
consequently to its axis. Its anterior portion is thick, 
its posterior is thin. The weight of the skull tends 
inevitably to press the condyles within the concavity 
of the atlas, and it follows that the line of this pres- 
sure will be downward and inward, and more at the 
anterior part of the condyle than at the posterior. The 
convergence of the condyles tends to effect a union of 
the lines of support and to transfer them from the 
condyles to the axis of the skull; so in effect the 
basilar process and the body of the sphenoid bone 
receive the weight of the skull plus that of the face. 
The skull, however, is not balanced upon the verte- 
bral column, but inclines to drop forward. This ten- 
dency is made necessary by the action of the post- 
cervical and the Sterno-Cleido-Mastoid muscles. 
THE SKULL CONSIDERED IN RELATION TO AGE. 
The description of the skull, as usually accepted, ap- 
plies to that of the adult only. Numerous modifica 
tions of the account given in the preceding section 
are required to properly define the skull before de- 
velopment is complete, or after old age has set in. 
Two types will be especially mentioned in this con- 
nection. These may be called the skull at birth, and 
the skull in extreme old age. 
The Skull at Birth.-The skull presents conspicuous 
prominences at the centres of ossification of the parietal 
and the frontal bones ; the region of the occipital pro- 
Fig. 68. 
tuberance is markedly convex. The sutural lines are 
straight or nearly so. The fontanelles are all present. 
The skull presents many negative features, such as 
the absence of basal processes-the pterygoid pro- 
cesses alone excepted; the external auditory meatus 
is undeveloped; the jaws are edentulous, and the 
alveolar processes absent; the glenoid fossa is shal- 
low, and affords little protection to the condyloid pro- 
cess of the inferior maxilla; the sinuses are rudimen- 
tary or absent. The peculiarities of proportion are 
numerous. The face constitutes but one-eighth of 
the entire figure, instead of nearly one-half in the 
adult. This is chiefly owing to the imperfect ver- 
tical growth of the bones. The orbits present deep 
depressions for the lachrymal glands. The entire 
cranium, as compared with the trunk, is large. Its 
length from the forehead to the occiput is great, as 
compared to its breadth. The breadth is great from 
one parietal protuberance to the other in proportion 
to the height. The brain case is shallow in comparison 
with its capacity anteriorly and posteriorly. The 
orbit is much less deep at the median wall in the 
infant, owing to the imperfect descent of the median 
structures of the face; the proportions of the lateral 
wall are about as in the adult. 
1 Holmes's System of Surgery, vol. ii. 158 
THE BONES. 
The, Skull in Extreme Old Age.-The skull in old 
age presents many distinguishing features. The 
sutures are nearly or entirely lost (see p. 156). The 
walls of the brain-case. are ordinarily thin from 
atrophy, while the teeth are absent and the alveoli 
absorbed. The skull is much lighter than in the 
mature adult, and the weight of the face is materially 
lessened. As a consequence, the skull is more readily 
balanced upon the vertebral column, thus making up 
for the withdrawal of the muscular power so essential 
to the maintenance of the head in man in his prime. 
The spheno-orbital septum, the roof of the tympanum, 
the orbital plate of the frontal bone, the os planum of 
the ethmoid, may be perforated. Other small pro- 
cesses, such as those tending to close the orifice of the 
maxillary sinus, may disappear. The pterygoid pro- 
cess is straighter than in the adult, and flattened in 
front. Owing to the absorption of the tooth-pits, it may 
descend far below the level of the hard palate. The 
prominence of the hamular process in consequence 
can be felt within the mouth during life. The outer 
pterygoid plate is often widened and extended some 
distance downward along the plane of the lower fibres 
of the External Pterygoid muscle. The triangular 
cartilage of the nose is often ossified; the sinuses are 
generally enlarged, though these may be even smaller 
than in the adult; and the jugular process is enlarged 
and inflated. 
THE HYOID BONE. 
The hyoid bone (figs. 1, 2, Plate XXV.), so called 
from its resemblance to the Greek letter v, lies in the 
region of the neck between the tongue and the larynx, 
with its convexity directed forward and its concavity 
backward. It is superficial, permitting the general 
outline of the bone to be traced beneath the skin in 
the undissected subject. 
The hyoid bone is composed of a body and two 
pairs of processes.-The body is somewhat quadrilate- 
ral in form, and is nearly twice as wide as high. The 
anterior surface is convex and well marked at the 
upper half by muscular impressions for the Genio- 
Hyoid muscles. These impressions look upward, and 
are sharply separated from the rest of the anterior 
surface which looks directly forward. The compressed 
median interval between these impressions is some- 
times prominent and ridge-like. The posterior sur- 
face is smooth and deeply concave. The upper border 
is thin, and continuous with the inner and upper mar- 
gin of the greater horn. The lower border is thicker 
than the superior, and is obscurely angulated laterally 
at the place of origin of the Omo-Hyoid muscles. The 
lateral border being continuous with the greater horn 
is seen only in the undeveloped bone. 
The processes are two in number on each side, and 
have received the names of the greater and the lesser 
cornua or horns. 
The greater horn is a long, irregularly club-shaped 
process, which is directed upward and backward, and 
is gradually narrowed posteriorly to end in a bulb-like 
tip.-The lesser horn is a small, peg-shaped nodule, 
ascending nearly at a right angle from the plane of 
junction of the body and the greater horn laterally. 
A joint ordinarily exists between the process and the 
rest of the bone. 
The hyoid bone gives attachment by its lower bor- 
der to the thyro-hyoid membrane; by the tip of the 
greater born to the thyro-hyoid ligament; by the tip 
of the lesser horn to the stylo-hyoid ligament. In 
addition to the Genio-IIyoid and Omo-Hyoid muscles 
already mentioned, it gives origin to the Hyo-Glossus, 
Middle Constrictor, Sterno-Hyoid, Sterno-Thyroid, and 
Thyro-Hyoid muscles, and insertion for the Mylo- 
Hyoid, and Stylo-Hyoid muscles. 
Development.-The hyoid bone arises from five 
centres of ossification, one for the body and one for 
each of the horns. The centres for the body and the 
greater horns appear in the ninth month of foetal life. 
The centre for each of the lesser horns appears during 
the first year. The lesser horn remains cartilaginous 
until advanced life. 
Remarks.-The greater horns of the hyoid bone 
are rarely exactly similar. The left lesser horn is so 
EXPLANATION OF PLATE XXV, 
Fig. 1. The hyoid bone, seen from above. 
Fig. 2. The hyoid bone, seen from in front. 
Fig. 3. The thorax. 
Fig. 4. The sternum and the costal cartilages, seen from in 
front. PLATE XXV 
Fig. 3 
Fi g. 2 
ng' ] 
F1§ . 4 
T.Sinr'cAr * THE TRUNK. 
159 
often longer than the right that some authors have 
described such a condition as normal.-The hyoid 
bone is raised in the second portion of the act of deg- 
lutition, but falls at the end of that act. It is depressed 
by the action of the Sterno-Thyroid, the Thyro-Hyoid, 
the Omo-IIyoid, and the Sterno-IIyoid muscles. The 
greater cornua serve to keep the laryngo-pharynx 
patulous in the way that the blades of a glove-stretcher 
act on a finger of a glove. Directly behind the body 
lie the fatty fibrous tissues about the base of the epi- 
glottis.-From the movability of the bone it is capable 
of being displaced by tumors. Gibbs1 describes a 
tumor arising from the thyroid cartilage, producing 
such displacement. Retro-pharyngeal abscess at the 
portion of the pharynx answering to the plane of the 
hyoid bone has also been known to displace the cornu 
of the corresponding side, and to produce conspicuous 
deflection of the larynx from the median line.-Grasp- 
ing the throat at the position of the hyoid bone may, 
by the forcible approximation of the greater cornua 
toward each other, cause either fracture or disjunction 
of its several parts. The bone may be also fractured 
in execution by hanging. 
THE RIBS. 
The ribs (figs. 4 and 5, Plate XXVI.; fig. 3, Plate 
XXV.) are those curved flat bones extending from the 
spine to the costal cartilages. They are twelve in 
number, and form a series of narrow arches which 
make up the lateral, the posterior, and in part the 
anterior, boundaries of the thorax. These arches are 
either prolonged by the costal cartilages to the ster- 
num, when the ribs entering into them are called the 
true or sternal ribs, or they fail to join the sternum, 
when the ribs entering into them are called the false 
or asternal ribs. The true ribs are those included 
between the first and the seventh ; while the false ribs 
make up the remaining five. Of the latter the eighth, 
the ninth, and the tenth are connected by their costal 
cartilages, and are held to one another as well as to 
the cartilage of the seventh rib. The eleventh and 
twelfth ribs are without fixation, and are from this 
circumstance known as the floating ribs. At times 
the tenth costal cartilage remains unattached to the 
ninth, when the number of floating ribs is three. 
The classification of the ribs into the true and the 
false, and the restriction of the last two ribs to a 
separate group, are in some respects unsatisfactory. 
In a proper sense all the ribs are true ribs, since they 
vary only in the single feature of the degree of fixa- 
tion of the anterior ends. Sibson1 very properly says 
that it is in the dead body only that the ''floating ribs" 
can be said to float; for in the living body they are 
steadied by powerful respiratory muscles. While 
the task of criticizing the nomenclature of the ribs is 
an easy one, attempts to improve upon the nomencla- 
ture have not been successful. Sibson2 proposes the 
term diaphragmatic ribs to include the last four, since 
these are moved actively by the Diaphragm, the other 
ribs being termed by him the thoracic. Why all the 
ribs are not thoracic is not made clear by this arrange- 
ment, nor is it reasonable to omit the sixth and 
seventh from the diaphragmatic ribs. 
Since the first six ribs present convex lower bor- 
ders, give origin to the Pectoralis Major muscle (an 
elevator of the ribs), and move upward in inspiration; 
and since the last six ribs present concave lower bor- 
ders, give origin to the Diaphragm (a depressor of the 
ribs), and move downward in inspiration, no objection 
can be urged to the use of the term " upper ribs'11 to 
designate the former group, or to the use of the term 
" lower ribs11 to designate the latter. For clinical pur- 
poses this classification is all that is needed, and has 
at least the advantage of simplicity. At the same 
time it is convenient to retain the terms "true, false, 
and floating ribs," since they are separated from 
one another by trenchant and easily remembered 
characters. 
The ribs increase in size from the first to the eighth, 
and decrease from the ninth to the twelfth. Each 
rib presents for examination a head, or vertebral ex- 
tremity, a sternal or anterior extremity, a neck, a 
tubercle, a body, and an upper and a lower border. In 
addition, the majority of the ribs present an angle, 
and three articular facets; of the latter, two belong to 
the head, and one to the tubercle. 
The head or vertebral extremity is furnished with an 
articular surface, which, in all the ribs excepting the 
first, eleventh, and twelfth, yields two facets, the lower 
of which is the larger. A faint ridge (crista capi- 
tuli) separates the facets for the attachment of the 
interarticular ligament. The head of each of the ribs, 
as above limited, articulates with a pair of vertebrae 
as follows: first, with the body of the vertebra corre- 
sponding in number to that of the rib; and, secondly, 
with the body of the vertebra directly above it. The 
portion of the bone lying between the head and the 
tubercle is called the neck.-The neck is best developed 
Diseases of the Throat, 277. 
1 Medical Anatomy, 1869, col. 62. 
2 L. c., 1869, col. 62. 160 
THE BONES. 
in the upper ribs, and is almost entirely absent in the 
eleventh and the twelfth. It is a flattened or irregu- 
larly prismatic process ; smooth within and roughened 
without for the attachment of the middle costo-trans- 
vcrse ligament. Its upper border is slightly elevated 
from the seventh to the tenth ribs to give attach- 
ment to the anterior costo-transverse ligament.-The 
tubercle lies at the junction of the neck with the shaft. 
An articular facet is here seen which looks downward 
and outward to articulate with the transverse process 
of the vertebra to which the rib belongs. To the 
outer side and above the facet is a rough eminence 
for attachment of the posterior costo-transverse liga- 
ment.-The body of the rib is that portion lying be- 
tween the tubercle and the sternal extremity. It is 
smooth on its inner side, but roughened on its outer, 
for the attachments of muscles, chief among which 
are slips of origin of the Serratus Magnus. Its upper 
border is thin and compressed in the first, the second, 
the eleventh, and the twelfth ribs, but rounded for 
the remaining ones. In all, the upper border presents 
a roughened surface for the attachment of the Inter- 
costal muscles. The lower border is grooved (see Inter- 
costal Muscles) from about the angle to near the 
anterior extremity for the reception of the intercostal 
vessels and nerve. The upper edge of the groove gives 
origin to the Internal Intercostal muscle; the lower 
edge, which is slightly produced, gives origin to the 
External Intercostal muscle.-The angle is that por- 
tion of the rib in connection with the insertion of slips 
of the Sacro-Lumbalis muscle. It determines the 
limits of the medio-dorsal aspect of the thorax, i.e., the 
space limited by points at which the ribs are abruptly 
directed forward. Almost absent on the first rib, the 
angle is slightly developed on the second, third, and 
fourth ribs; it increases in size until the eleventh is 
attained, beyond which it again decreases, and is 
entirely absent on the twelfth.-The sternal extremity 
of the rib is broader than the body, excepting from 
the ninth to the twelfth ribs, where it is smaller. The 
borders of this extremity are obtuse; the terminal 
surface is concave for the corresponding costal carti- 
lage. The sternal end of the costal curve has been 
called, on perhaps insufficient grounds, the anterior 
angle.1 
The Twist of the Rib.--The general form of the rib, 
while arched outward and forward, is curved down- 
ward, so that the sternal end is lower than the verte- 
bral. As the ribs increase in length from above 
downward the tendency of the inner surface near the 
vertebral end to be inclined downward and inward is 
decided. In common with this the surface about the 
middle of the body of the bone is inclined downward 
and outward. The gradual change from one to the 
other inclination, conjoined with the tendency con- 
stantly present of the sternal end of the bone to as- 
sume a position below the plane of the vertebra to 
which it belongs-a tendency best seen in the ribs 
from the fifth to the ninth-gives a spiral shape to the 
bone which has been described as the twist of the rib. 
This shape is more evident in the isolated bone than 
in articulation. 
Peculiar Ribs.-The foregoing description is appli- 
cable to a rib situated between the third and the tenth. 
It would not apply to the others, for the following 
considerations:- 
The first rib is placed more horizontally than the 
other ribs, and yields a shorter curve. Its outer sur- 
face looks upward, and its inner surface looks down- 
ward. The head bears a single articular facet, and 
articulates with the first dorsal vertebra alone. Its 
upper surface is marked by a faint ridge which termi- 
nates in a tubercle upon its upper border for the inser- 
tion of the Scalenus Anticus muscle. In front of this 
is a broad shallow groove for the subclavian vein; 
behind it lies a second deeper groove for the subclavian 
artery. To the outer side of the groove for the sub- 
clavian artery is a rough surface for insertion of the 
Scalenus Mcdius muscle. The tubercle of the first rib 
is the largest of any of the ribs, and is firmly sup- 
1 Cruveilhier, Anatomy, 1. c., Birkett, Trans. Path. Soc. of Lond., 
1853, 105. 
EXPLANATION OF PLATE XXVI. 
Fig. 1. The clavicle, seen from beneath. 
Fig. 2. The clavicle, seen from behind. The nutritious 
foramen lies directly above the letters "Fig. 2." 
Fig. 3. The clavicle, seen from in front. 
For " sterno-mastoid" read " sterno-cleido-mas- 
toid." 
Fig. 4. The first rib, seen from above. 
Fig. 5. The second rib, seen from above. PLATE XXVI 
Fig.l 
Fig.2 
Fig-3 
Fig.4 
Fig 5 
T. Sinclair Oan, lifh THE TRUNK. 
161 
ported by the transverse process of the first dorsal 
vertebra. The angle is almost absent, and no groove 
exists for the intercostal vessels and nerve. The 
sternal extremity is thicker than in any of the true 
ribs. 
The second rib agrees with the first in being more 
horizontal than the other ribs. Its head presents a 
faint interarticular ridge. It is marked upon its outer 
surface by a large rough surface for attachment of the 
Serratus Magnus muscle. 
The eleventh and twelfth ribs yield larger curves 
than do the other ribs. Their inner surfaces opposite 
the neck are more inclined, while, as already seen, 
the anterior extremities are narrowed. 
In addition to the above characters of the ribs the 
following may be considered with advantage in iden- 
tifying isolated ribs or fragments :- 
The facet of articulation with the transverse pro- 
cess of the vertebra is in the first rib carried upon 
the end of a short process, which is directed slightly 
downward, so that the end of the process is best 
seen upon the lower surface of the rib. The ribs from 
the first to the sixth seen in articulation from the in- 
terior of the thorax present at the point answering to 
the neck a vertical surface, and exhibit from the up- 
per borders of the smooth surfaces entering into the 
pulmonary sinus a slight crest for the anterior costo- 
transverse ligament. The ribs from the seventh to 
the twelfth present from within the thorax a slightly 
inclined surface at about the neck, and each bears a 
sharp crest at the upper border. 
Structure.-The ribs are cancellous throughout 
(being least so at the angle), with firm lateral walls. 
Development.-Each rib arises from a single centre 
of ossification for the body which appears as early as 
the eighth week, and from two small accessory cen- 
tres, one appearing in the head and the other in the 
tubercle. The rib is completed at about the twenty- 
fifth year. 
Remarks.-Deformity of the rib may be either con- 
genital or acquired. Dr. Robert Adams has recorded1 
an instance of congenital deformity of the first pair of 
ribs. The left rib was two inches long and straight, 
and presented a free projecting, somewhat flattened 
extremity, which was joined to the second rib by a 
process ascending from the latter. The left sub- 
clavian artery ran in front of the distal extremity 
of the deformed rib as above described, and was 
supported by the bony elevation of the second rib. 
The right first rib was shortened and malformed, and 
supported the right subclavian artery.-A forked rib 
is one which sends oft' a process either above or below 
the main costal axis. It may end in an intercostal 
space, or, advancing forward, may be joined by an in- 
tercostal cartilage.-The sternal ends of the ribs are 
apt to be deformed in rickets.-Dislocation of the rib is 
a rare lesion.1-The ribs are among the most vascular of 
the bones, and are hence liable to caries and inflamma- 
tion.-The angles of some of the ribs are so roughened 
externally that a careless observer may mistake such 
appearances for the effects of old fractures. The inner 
aspect in such specimens is always smooth, and 
can thus be distinguished from ribs that have been 
fractured. The last cervical (see p. 114) and the first 
lumbar vertebra rarely bear rib-like processes. The 
last-named rib is the more frequent. The twelfth rib 
may be absent or smaller than usual.-The ribs that 
are most exposed are those included between the 
fourth and the tenth, and these therefore suffer most 
from direct violence. In fracture the bone most fre- 
quently gives way at the angle or near the sternal end. 
THE COSTAL CARTILAGES. 
Attached to the sternal ends of the ribs are twelve 
cartilages which, from their resemblance to the ribs, 
have received the names of the costal cartilages 
(fig. 4, Plate XXV.). In the upper ribs these carti- 
lages lie between the sternal ends of the ribs and 
the side of the sternum; in the lower ribs they 
either lie between the sternal ends of the ribs and the 
borders of adjacent ribs, or, as in the last two, they 
serve as tips simply to their respective bones. The 
cartilages of the false ribs aid in defining the inferior 
margin of the thorax anteriorly. The ends of each 
cartilage are convex, and are secured in correspond- 
ing depressions on the ribs and the sternum. The 
union of the cartilage with the corresponding rib is 
in all instances without articulation; but the union of 
the cartilage with the sternum is diarthrodic, except- 
ing that of the first rib. 
Respecting the shape of the costal cartilage it may 
be said that the costal portion of each cartilage is in 
the line of the sternal end of the rib to which it be- 
longs. In the ribs from the first to the fourth, and in 
1 Dublin Path. Soc. Trans., 1839, quoted in Med.-Chir. Trans., 
lii. 288. 
1 Buttet, Mera, de Chirurg., v. 1784, 593. 162 
THE BONES. 
the eleventh and the twelfth, the entire cartilage is 
thus placed ; but in the remaining ribs the costo- 
axial portion is less than one-half of the entire length 
of the cartilage. The remaining or sternal portion 
ascends at an angle to the costal, either to join the 
sternum or the adjacent cartilages. The degree of 
ascent in each cartilage bears an exact relation to the 
downward inclination of the rib to which it belongs. 
The sternal end is narrowed to a greater or less degree 
in all the costal cartilages excepting the first. 
The movements of the upper costal cartilages are 
more or less limited, if indeed they are not entirely 
absent at the region of the first rib. The move- 
ments of the lower ribs, on the other hand, are very 
free; they expand the base of the thorax in inspira- 
tion. Hence the costal cartilages may be said to 
increase the basal measurement of the thorax while 
aiding the ribs in maintaining the elasticity of the 
thoracic walls. Owing to ossification of the cartilages, 
this elasticity diminishes in adult life, especially at 
the region of the upper ribs. In old age the costal 
cartilages are almost invariably ossified. In adult life 
they may be fractured. 
THE STERNUM. 
The sternum, or the breast bone (fig. 4, Plate 
XXV.), is a large flat bone placed at the anterior part 
of the thorax, and is held in position by the ribs. It 
assumes a slanting position downward and forward, 
so that its anterior surface looks slightly upward, and 
its posterior looks downward and .backward. Its 
upper border is thus nearer the vertebral column 
than the lower, and answers in position to about the 
level of the second dorsal vertebra. The sternum is 
from seven to eight inches long, by one-and-a-half to 
two inches wide, and is six lines thick at its lower 
part. It is broader above than below, and is marked 
upon the sides along nearly its entire length by con- 
cave depressions for union with the costal cartilages. 
The sternum bears a rude resemblance to an ancient 
Roman sword, and its several portions have been 
named in consequence the manubrium (handle, pre- 
sternum), the gladiolus (body, blade, mesosternum), 
and the ensiform process or cartilage (xyphoid cartilage, 
tip, metasternum). The line of junction between the 
manubrium and the gladiolus forms a distinct trans- 
verse ridge upon both the anterior and the posterior 
aspect of the bone. The former is often visible in 
the living subject. 
The manubrium is the stoutest and thickest portion 
of the bone. It is broad above, somewhat contracted 
below. It is a little less than half as long as the 
gladiolus, and serves for articulation with the first 
pair of ribs and the clavicles. Its upper margin is 
thick and rounded, and is transversely concave to form 
a semilunar depression-the inter-clavicular notch 
(fourchette)-which is covered by the inter-clavicular 
ligament, and is deepened in life by the median ends 
of the clavicles. Upon either side of the notch are 
the articular, saddle-shaped surfaces for the last-named 
bones. They are directed downward and outward, 
are concave from without inward, while convex from 
before backward. The lower margin of the manu- 
brium is nearly flat for articulation with the gladiolus. 
The sides are marked above by the simple depression 
for the first costal cartilage, and below by the half 
facet entering into the costo-sternal articulation of 
the second rib. The first-named joins the outer 
border of the clavicular articular surface, and is in- 
clined obliquely downward. The manubrium has the 
following muscular attachments: the Sterno-Cleido- 
Mastoideus, the Sterno-Hyoid, and the Sterno-Tbyroid 
muscles; the last two appearing upon the posterior 
surface.1 
The gladiolus is somewhat egg-shaped, being slightly 
broader below than above. Its lateral margins are 
marked by double-faceted depressions for the costal 
cartilages, in such order that the second rib joins the 
manubrio-gladiolar junction, and the seventh rib joins 
the gladiolus and the ensiform cartilage. The remain- 
ing costal cartilages are separated by semilunar de- 
pressions, which toward the lower end of the bone 
are nearly if not quite contiguous. The anterior sur- 
face is marked by three transverse lines, which indi- 
cate the union of the four pieces of which this por- 
tion of the sternum originally consists. An opening 
(sternal foramen) indicating a defect of development 
between the third and the fourth pieces is occasionally 
found. The gladiolus gives attachment to the Pecto- 
ralis Major in front and to the Triangularis Sterni 
behind. 
The ensiform process or cartilage is a thin spatula- 
like process having a variable length of from one-half 
inch to one-and-a-half inches. It is depressed below the 
level of the lower extremity of the gladiolus, so that 
when the integument covering it is in position a pit is 
demonstrable, consisting of the so-called scrobiculus 
cordis, or pit of the stomach. It is embraced by the 
linea alba. The anterior surface gives attachment to 
the costo-xyphoid ligaments; the posterior surface to 
1 By a mechanical error the attachment of the last-named muscle 
is represented in the figure upon the anterior surface. THE TRUNK 
163 
the Diaphragm and the Triangularis Sterni muscle. 
Its borders are attached to the aponeuroses of the 
abdominal muscles.-The ensiform cartilage is the 
most variable portion of the sternum. Instead of 
being spatula-like, it may be rounded, or forked. It 
may be deflected from the median line, or even turned 
directly backward. It is sometimes furnished with 
foramina.-According to Sibson,1 the basal half inch 
of the ensiform cartilage receives at its side the fibres 
of the Diaphragm that appear in the notch between 
the cartilage and the seventh rib. The pleura lines 
these fibres posteriorly. 
Structure.-The sternum is composed of small, 
very vascular cancelli, inclosed between the anterior 
and the posterior walls. 
Articulations.-The sternum articulates with 
the clavicles and the costal cartilages from the first 
to the seventh inclusive. 
Development.-The first centre of development 
appears in the manubrium at the fifth or the sixth 
month of foetal life, and is usually single. The upper 
portion of the gladiolus forms a distinct segment, and 
arises from a single centre at the seventh month. For 
the remaining three segments the centres ordinarily 
appear in pairs within the first year. The ensiform 
process does not ossify until the sixth year. The 
gladiolus is complete about the twenty-fifth year. 
The sternum rarely or never completely ossifies, 
except in old age. Thus the manubrium and the 
gladiolus are united by cartilage. The remaining 
portions, however, coalesce. The junction between 
the ensiform process and the gladiolus is perfected at 
about middle life, and the different portions of the 
gladiolus from the twentieth to the fortieth year. 
Congenital defects of the sternum ordinarily have 
their origin in the failure of the bi-lateral centres of 
the gladiolus to unite in whole or in part. 
Remarks.-The sternum from its cancellated struc- 
ture is a relatively vascular bone, and responds to 
diseased action very much after the manner of spongy 
bone elsewhere. It is, as a consequence, a frequent site 
of caries, particularly in the negro ; it is the locality 
to which the pains of constitutional syphilis are com- 
monly referred. It yields readily to pressure, as from 
an aortic aneurism, and can be perforated by sharp 
cutting instruments.-The sternum is subject to con- 
siclerable variation in form. Thus, the two clavicular 
facets may not be of exactly the same height; a sup- 
plemental pair of costal cartilages are rarely appended 
to the base of the ensiform cartilage. As already 
mentioned, one or more rounded openings, resulting 
from defective ossification, are occasionally seen in the 
gladiolus. Instances have been collected of punctured 
wounds received through such spaces-while medi- 
astinal abscesses have opened through them.1 The 
transverse line between the manubrium and the 
gladiolus is often so pronounced as to resemble an 
old fracture.-The ensiform cartilage, when deformed 
either by growth or by vicious position after injury, 
may by its backward pressure excite irritation.2 
The sternum is covered by fibrous tissue on all its 
surfaces, recalling in both position and use the peri- 
osteum. The anterior fibrous layer is composed of 
fibres which cross one another in every direction, and 
which are closely adherent to the surface of the bone 
and the cartilages. The posterior layer is composed 
chiefly of longitudinal bands of white fibrous tissue, 
which are but slightly adherent to the bones and the 
costo-sternal articulations.3 It is much stouter than 
the anterior, and in dislocation of the parts of the 
sternum on each other may be stripped from the bone. 
In the now nearly obsolete operation of trephining 
the sternum, this membrane is an obstacle to the easy 
removal of the circle of bone.4 
The joint between the manubrium and the gladio- 
lus, according to Maisonneuve,5 is either fibrous or 
diarthrodial; it is fibrous in character in about twenty- 
five per cent, of cases, and diarthrodial in seventy-five 
per cent. The joint is rarely obliterated.6 
When the diarthrodial joint exists, the layer of 
fibro-cartilage belonging to the gladiolus is continued 
on each side without interruption to the facet destined 
for the cartilage of the second rib, whilst the layer 
belonging to the manubrium adheres to the upper 
border of the second costal cartilage. The latter slip 
is separated as a rule from the manubrium by a 
synovial membrane. It is absent in about three per 
cent, of specimens. It follows upon this arrangement, 
according to Maisonneuve, that the second rib is much 
1 Cruveilhier, Anatomy of the Human Body (Am. ed.), 1844, 65. 
2 Blandin, Topograph. Anat., Doane edition, 1834, 163. 
3 Jno. H. Brinton, Am. Journ. Med. Sei., 1867, 39. 
4 Hyrtl, Topograph. Anat., i. 548. 
5 Archives Generates de Medecine, iii. Serie, xiv. 1842. 
6 Brinton, Jno. II., 1. c. W. Rivington, Med.-Chir. Trans., Ivii., 
1874, 112, found one-half per cent, to be fibrous, one-third to be 
diarthrodial, and the remainder to be intermediate between the two 
already named, or obliterated by ossification. The diarthrodial 
form is more commonly met with in males than in females. 
1 Medical Anatomy, 1. c. 164 
THE BONES. 
more strongly attached to the manubrium than to 
the gladiolus. This explains the fact that in luxation 
of the manubrium or the gladiolus the latter always 
abandons the cartilage of the second rib, while the 
former remains constantly united to it. 
Episternal bones in the form of small sub-rounded 
nodules attached to the upper margin of the manu- 
brium are rarely seen.1 They are situated on either 
side of the interclavicular notch, and are homologous 
with the larger bones of the same name in the mono- 
treme mammals. In man they are of use in giving 
increased support to the thoracic ends of the clavi- 
cles.-A tumor of the sternum simulating aneurism 
has been described by Ollivier.2-The projection on 
the anterior surface of the bone at the union between 
the manubrium and the gladiolus, when pronounced, 
retains the mediaeval name of the angulus Ludovici. It 
indicates recession of the first pair of ribs, and is often 
found associated with other tubercular tendencies.- 
The skin over the sternum retracts to a great degree 
after incision. More than usual care should as a result 
be taken in making incisions in this region of the 
body.3-For differences in the measurements of the 
sternum in the male and the female, see page 102. 
The sternum being suspended to the costal carti- 
lages follows tho movements of respiration. The 
lower portion is pushed forward in inspiration, while 
the bone is raised. It follows that the relations of 
the sternum to the fixed parts will vary. Subject 
to slight modification it may be said that the upper 
margin of the sternum answers to the second dorsal 
vertebra or to the second dorsal spine; the junction 
between the manubrium and the gladiolus is opposite 
the third dorsal spine, and the junction between the 
gladiolus and the ensiform cartilage is opposite the 
sixth dorsal spine.-The median line of the sternum 
is not parallel to the median line of the abdomen, but 
forms with it an angle at the ensiform cartilage which 
is directed to the right.4 
THE THORAX. 
The thorax is that portion of the skeleton formed 
by the articulation of the ribs, the costal cartilages, 
the sternum, and the dorsal vertebra. In the undis- 
sectcd subject, the thorax is equivalent to the chest of 
common language, and includes the Intercostal mus- 
cles at the sides and the Diaphragm at the base. The 
thorax is the great respiratory cavity of the body as 
well as the chamber for protection to the heart, and 
in some degree to the great vessels, the oesophagus, 
and in the foetus to the thymus gland. 
The figure of the thorax is conical, compressed from 
before backward, and presents oblique upper and 
lower surfaces. It is grooved longitudinally on either 
side of the spinous processes at the back; it is flat, 
and inclined slightly forward in front, and is convex 
at the sides. Within, the thorax presents a general 
concave surface except posteriorly, where the bodies 
of the dorsal vertebrae project forward. Its greatest 
circumference is about its middle or a little below, 
where its average measurement is twenty-five inches. 
The thorax presents forexamination the dorsal ver- 
tebrae, the ribs, the costal cartilages, and the sternum 
(which have been described), as well as the superior 
and inferior apertures, and the intercostal spaces. 
The superior thoracic aperture is bounded behind 
by the body of the first or second dorsal vertebra, at the 
sides by the first pair of ribs and the costal cartilages, 
and in front by the upper border of the sternum. It is 
kidney-shaped, its antero-posterior (sagittal) diameter 
being a little over two inches, while its transverse 
(frontal) is nearly five. It contains the oesophagus, the 
trachea, the apices of the lungs, the pleurse, the sub- 
clavian arteries and veins, the carotid arteries, the 
internal jugular veins, the termination of the thoracic 
ducts, and the lymphatics and nerves. 
The inferior thoracic aperture is of an irregular 
figure, owing to the absence of union of the eleventh 
and twelfth ribs with the other ribs or sternum. It 
is less fixed in its outline as compared to the superior 
aperture, in consequence of the larger proportion of 
cartilage intervening between the ends of the ribsand 
the sternum. It is closed by the Diaphragm in the 
subject, yet permitting the passage of the inferior vena 
cava, the aorta, the oesophagus, the main thoracic 
duct, and the sympathetic nerves. 
The intercostal spaces are narrower behind than in 
front, and with the upper ribs they are widest at 
about the junction of the ribs and the costal carti- 
lages. The spaces between the false ribs naturally 
lessen in width as the cartilages converge towards 
each other. The spaces are occupied in the subject by 
the Intercostal muscles, the arteries, and the nerves. 
The first and the second are larger than the others, 
but on the whole the spaces tend to increase from 
above downward-that between the sixth and the 
seventh rib being the widest at the sternal margin. 
1 Luschka, Zeit. fur wissenschaft. Zool., 1852, 36; T. W. King, 
Guy's Hosp. Rep. v. 1840, 227. 
2 Comptes Rendus, 1868, 221. 
3 Richet, Anat. Medico-Chirurg., 545. 
4 Sibson, 1. c., quoted from J. W. Conradi. Upon the Position 
and Size of the Thoracic Organs. Giessen, 1848, 3. THE TRUNK. 
165 
In addition to the terms superior and inferior aper- 
tures the terms apex and base are in use by clinical 
writers. The apex is vaguely defined, and may be 
said to answer to the upper portion of the cone-like 
figure of the thorax. It has also been said to accom- 
modate the apical portions of the lungs. In conse- 
quence of the fact that the' apex of the lung is not 
confined to the thorax, the latter determination can 
have but slight significance. The base of the thorax 
is of much more value. It is defined by Sibson1 in 
the following language: The base extends like a 
girdle across the lower ribs from the end of the eighth 
rib in front to that of the twelfth behind, and answers 
to the circuit at which the pleura is reflected from the 
Diaphragm upon the ribs and the Intercostal muscles, 
and down to which the lungs can descend during the 
deepest possible inspiration in the living, and when 
distended to the full in the dead. In such a position 
as the one last named, the base of the thorax is almost 
a straight line, crossing the extremities of the four 
lower ribs in an oblique direction from before back- 
ward and downward. 
Remarks.-The shape of the thorax and the pro- 
portion it bears to the rest of the body are subject to 
much variation. In the infant the thorax is rela- 
tively smaller than in the adult. In the female the 
upper portion of the thorax is less compressed from 
before backward, and is more capacious than in the 
male; the superior thoracic aperture is larger, and 
the motions between the upper ribs and the sternum 
and the vertebrae are more conspicuous. From these 
circumstances the respiratory movement in the thorax 
of the female is decided as compared with that of the 
male, and has from this circumstance been called 
thoracic. In the male the lower ribs and the abdo- 
minal walls are seen moving more freely than the 
upper; so that with him respiration is said to be 
abdominal. 
The thorax is of necessity modified in shape by the 
condition of its contents. When the lungs are ex- 
panding as in inspiration, the ribs from the first to 
the sixth (upper ribs) are raised toward one another 
so as to narrow the intercostal spaces, the sternum 
ascends, and the anterior thoracic aperture assumes a 
nearly horizontal position. At the same time the 
ribs from the seventh to the twelfth (lower ribs) are 
depressed so as to widen their intercostal spaces, and 
the inferior thoracic aperture is increased in size ; the 
twelfth rib remaining nearly stationary. When the 
lungs are contracted as in expiration the reverse of the 
movement described takes place. The upper ribs are 
far apart, and the remaining ribs are elevated and 
approximated at the side of the chest. 
In emphysema the characteristics of inspiration 
with bulging intercostal spaces, and in phthisis those 
of expiration with depressed intercostal spaces, are 
maintained and exaggerated. In chronic asthma a 
peculiar cylindroid form of thorax is detected, which 
has received the name of the " barrel chest." 
The respiratory movements may, indeed, be said to 
determine the shape of the thorax. Even in the arti- 
ficial skeleton the disposition of the ribs from the 
first to the sixth to present convex lower borders, and 
that of the ribs from the sixth to the tenth to present 
concave lower borders, is evident. By this character 
the ribs that ascend in respiration can be distinguished 
from those ribs that descend in respiration, the latter 
being least marked in the case of the eleventh and 
the twelfth. 
A careful inspection of the interior of the thorax 
in the skeleton is useful. The first and second ribs 
directly overlie the thoracic chamber, forming its 
roof; the remaining ribs lie at the sides. It is evi- 
dent that the first-named ribs will yield a percussion 
note answering more exactly to the resonance of 
the entire thoracic space than will one elicited from 
the ribs either at the sides or at the back.-The pro- 
jection of the line of bodies of the dorsal vertebrae 
forward, and the curvature of the ribs, give to the 
transverse sections of the thorax a kidney-shape. 
The vertebral column answers to the hilus of this 
figure, and the deep symmetrical curves on either side 
to the surface above and below the hilus. These deep 
curves lying between the sides of the vertebrae and 
the sides of the thorax correspond to the posterior 
thoracic surface, and may receive the name of the 
pulmonary sinuses, since they lodge the convex poste- 
rior surfaces of the lungs. 
The form of the thorax is in great measure con- 
cealed in the undissected subject. The clavicles and 
the muscles attached to it obscure the outline of the 
first and second ribs. The scapula, when the arms 
are at rest, covers in and conceals the dorsal surface 
from the second to the eighth or ninth ribs. In front, 
at the back, and at the sides, muscular masses protect 
the parietes as with pads or cushions, and remove 
many of the costal surfaces from observation and the 
touch. It is well to remember that even in very 
muscular or fleshy individuals the following points 
can always be made out, no mention of the sternum 
and the beginnings of the costal cartilages being 
1 Medical Anatomy, col. 37. 166 
THE BONES 
thought necessary. The anterior border of the Pec- 
toralis Major answers to the line of the fifth rib. 
The first visible digitation of the Serratus Magnus is 
attached to the sixth rib; the second digitation to the 
seventh rib. The hand of the subject or model being 
placed upon the head exposes the axilla, which is 
defined by the Pectoralis Major and Pectoralis Minor 
in front, and by the Latissimus Dorsi, Teres Major, 
and Subscapular muscles behind: the Serratus Magnus 
forms the floor of the axilla, which corresponds to the 
space from the second to the fifth ribs. In this space 
the lung-sounds can be heard with greater ease than 
at any other part of the chest, and they should here 
be sought, for in all careful examinations of the con- 
ditions of the apex.-Richet1 states that abscess of the 
axilla can cause irritation and thickening of the ad- 
jacent pleura by direct transmission through the tho- 
racic parietes. Holden3 suggests that the lines of the 
anterior and the posterior walls of the axilla produced 
down along the sides of the thorax should receive the 
name of the axillary lines.-The- nipple overlies the 
fourth intercostal space, the fourth or even the fifth 
rib. It varies in position according to the state of 
the thorax. In emphysema the nipple, if it remains 
stationary while the upper ribs ascend, would answer 
to the fifth, and in extreme cases to the eighth. On 
the other hand, in shallow chests with depressed ribs, 
as seen in phthisis, the nipple may answer to the 
fourth.-The costal cartilage of the seventh rib lies 
at the junction of the base of the ensiform cartilage 
with the gladiolus. This position can be readily 
determined on the subject through the integument, 
and an easy method is thus presented of fixing the 
anterior border of the inferior thoracic aperture.- 
The positions of the floating ribs can always be re- 
cognized by the touch. 
If a tape-line whose initial end lies over the sternal 
end of the first rib is drawn transversely across the 
front of the thorax, and thence to the spines of the 
vertebral column, the terminal end will be found to 
rest upon the vertebral end of the fifth rib. On such 
a basis Luschka has elaborated, as in the following 
table, a series of lines for all the ribs:- 
Table of Relations between the Anterior and Posterior Surfaces of the Thorax. 
STERNAL END. 
POSTERIOR EQUIVALENT. 
The Sternal end of the first rib is 
on the same line as 
the Vertebral end of the fifth rib 
CC 
c c 
CC 
second 
c c 
cc cc 
" " " seventh " 
CC 
CC 
CC 
third 
c c 
cc cc 
'' " " eighth " 
c c 
CC 
c c 
fourth 
cc 
cc cc 
" " " ninth " 
CC 
c c 
cc 
fifth 
c c 
cc cc 
" " " tenth " 
c c 
CC 
CC 
sixth 
c c 
cc cc 
Middle of the vertebral and of the space between the tenth and eleventh ribs 
c c 
c c 
cc 
seventh 
cc 
cc cc 
Vertebral end of the eleventh rib 
c c 
c c 
,c 
eighth 
c c 
cc cc 
Beginning of the transverse process of the first lumbar vertebra 
c c 
CC 
cc 
ninth 
c c 
cc cc 
Near the body of the second lumbar vertebra 
CC 
c c 
c c 
tenth 
c c 
cc cc 
Near the body of the third " 
c c 
c c 
c c 
eleventh 
c c 
cc cc 
cc cc cc ' cc 
CC 
c c 
cc 
twelfth 
c c 
cc cc 
cc cc cc cc 
From what has been said in connection with the 
subject of the respiratory movements of the thorax, 
it is evident that some variation will exist in these 
lines. In the thorax prepared in the form of inspira- 
tion the lines for the upper six ribs would lie some- 
what above the level of the vertebral equivalents 
jjiven in the table; in like manner, in the thorax 
prepared in the form of expiration, the lines for the 
lower ribs would be a little below. 
For the relations between the liver, the stomach, 
and the spleen and the base of the thorax, see the 
account of those organs. 
THE BONES OF THE UPPER EXTREMITY. 
The bones of the upper extremity are those of the 
shoulder, the arm, the forearm, and the hand; they 
include the clavicle, the scapula, the humerus, the 
ulna, the radius, the carpal bones, the metacarpal 
bones, and the phalanges. 
THE CLAVICLE. 
The clavicle, or the collar bone (figs. 1, 2, 3, Plate 
XXVI.), is the medium by which the superior ex- 
tremity is connected to the trunk. It is placed super- 
ficially, so that its superior and anterior surfaces can 
1 Anat. Medico-Chirurg., 877. 
2 Landmarks, 68. THE UPPER EXTREMITY. 
167 
be defined in the undissected subject between the 
thorax and the scapula, receiving above the insertions 
of muscles descending from the neck, and affording 
surfaces of origin to those ascending from the sides 
of the chest. The clavicle is inclined from the ster- 
num and the first costal cartilage (see fig. 3, Plate 
XXXVII.) a little diagonally outward and backward, 
and at the thoracic two-thirds is cylindroid, while at 
the scapular third it is flat, thin, and irregular. 
Seen from above, the bone is shaped like an italic 
letter /, placed horizontally; the initial right-hand 
curve is the thoracic end, the main stroke of the letter 
is the cvlindrical shaft or body ; the terminal curve is 
the scapular or acromial end. At the junction of the 
thoracic end with the shaft, on the under surface, the 
impression for the costo-clavicular ligament is seen; 
at the junction of the body with the scapular portion 
lies the conoid tubercle. 
The body of the clavicle extends from the outer 
margin of the impression for the costo-clavicular liga- 
ment to the conoid tubercle. It is slightly narrowed 
from before backward to give origin to the clavicular 
fibres of the Pectoralis Major muscle ; it is convex 
anteriorly and concave posteriorly. The curves of 
the body are continuous with those of the thoracic, 
but are abruptly separated from those of the scapu- 
lar end. The orifice of a nutritious canal directed 
laterally is seen on the posterior surface. Stretch- 
ing across the under surface of the body from the 
conoid tubercle in front to the posterior and in- 
ferior border is an oblique line which limits the 
surface of origin of the Pectoralis Major muscle 
inferiorly. Near the oblique line is the narrow 
depression for the Subclavian muscle. 
The thoracic end of the clavicle is nearly square, 
the anterior and the posterior .surfaces remaining as in 
the body, while the superior and inferior are broader. 
The superior smooth surface receives at its posterior 
border the insertion of the clavicular portion of the 
Sterno-Cleido-Mastoideus muscle. The anterior sur- 
face presents a ridge for the fibres of the Pectoralis 
Major, while the inferior surface toward its anterior 
aspect is roughened, as already mentioned, by the 
impression for the costo-clavicular ligament. The 
posterior surface is smooth. The articular surface is 
of a triangular or subrounded figure, the broadest 
portion being directed upward and forward, while the 
narrowest is downward and backward. The articular 
surface is depressed in the centre, and all the borders 
excepting the superior are rounded, and appear more 
or less upon the sides (fig. 2, Plate XXVI.). The 
antero-inferior lateral facet, as contrasted with the 
others, is limited abruptly by a sharply projecting 
lip. The lower end is the least liable of any part 
of the thoracic portion to be invaded by diseased ac- 
tion. In the macerated bone the articular surface is 
roughened and irregular, but in the subject it is 
smooth and saddle-shaped. 
The scapular or acromial end of the clavicle ex- 
tends from the conoid tubercle to the end of the bone. 
It is broad and flat, thicker behind than in front, 
sharply concave anteriorly and abruptly convex pos- 
teriorly. The anterior edge of the upper surface gives 
origin to the Deltoid muscle by a deep lunated impres- 
sion. Near the posterior border a faint ridge indicates 
the insertion of the clavicular fibres of the Trapezius. 
The under surface from the conoid tubercle forward 
and outward is irregularly ridged (oblique line) for 
the attachment of the coraco-clavicular ligament. The 
oval or rounded scapular (acromial) articular surface 
does not occupy the entire end; it joins the anterior 
edge of the bone, and looks obliquely downward and 
outward. 
Structure.-The clavicle resembles a long bone 
in presenting a shaft with walls and spongy extremi- 
ties. The shaft or body is in great part occupied 
by a number of lamellae, beginning and continuous 
with the thin anterior wall, and extending across the 
body near to the enormously thick posterior wall. 
The latter is thicker in the middle than towards the 
ends of the body, and is gradually lost within the 
thoracic and the scapular ends. At the junction of the 
body with the scapular end, the anterior is of equal 
thickness with the posterior wall, and the interior of 
the bone is filled with coarse, stout laminae. It is 
probable that the disposition of the parts last named 
explains the great relative frequency of fracture of 
the clavicle at the junction of the outer with the 
middle third of the bone as compared with fracture 
at any other portion. In the thoracic third the can- 
celli are small, and give increased compactness to the 
bone at this part. The uppermost cancelli, being here 
the weakest, are often exposed and disintegrated in 
cabinet specimens. In the scapular end the most 
compact tissue lies anteriorly in the line of the facet 
of articulation; posteriorly the cancelli resemble in 
structure and behavior the upper portion of the 
thoracic end already described. 
Development.-The clavicle arises from cartilage1 
by two centres of development: one for the main 
1 The bone is generally described, as arising from fibrous tissue. 
Gegenbaur (infra) is the authority for the contrary statement. 168 
THE BONES 
portion of the bone which appears about the sixth 
week, and one for the sternal end (pre-coracoid of 
Kitchen Parker) which appears after the manner of 
an epiphysis at about the eighteenth year. The 
epiphysis unites with the shaft at the twenty-fifth 
year. 
The clavicle is thought to be homologous with an 
intermuscular space or septum (such as the linea 
transversa of the Rectus Abdominalis) which lies be- 
tween the Trapezius and the Sterno-Cleido-Mastoid 
muscles on the one hand, and the Deltoid on the other. 
In animals without a clavicle, the Trapezius and the 
Deltoid muscles are continuous, as in the seal and the 
carnivora generally. In the bear a transverse fibrous 
inscription alone separates the Deltoid from the cra- 
nial fibres of the Trapezius. In the cat, the raccoon, 
and allied animals a small movable bone without 
osseous attachment of any kind intervenes between 
the two muscles. 
Remarks.-The clavicle is exceedingly variable in 
form. In muscular individuals the curves are pro- 
nounced, the thoracic articular surface is produced 
downward, and the facet answering to the upper sur- 
face of the first rib is large.-The impression of the 
claviculo-costal ligament is either on the level of the 
bone or raised slightly from it. This impression is 
sufficiently deep in the bone just prior to the union 
of the median epiphysis to lead observers to mis- 
take it for an effect of diseased action.-The lower 
border of the impression for the Deltoid sometimes 
projects as a ragged spine ; the posterior border of the 
acromial end is rarely produced to the level of the plane 
of the facet, thereby greatly increasing the width of 
the bone at that place.-In the female the clavicle is 
straighter than in the male, and the muscular and 
ligamentous impressions are but faintly marked. The 
ridge for the coraco-clavicular ligament is sometimes 
lumpish.-The clavicle occasionally exhibits a foramen 
at the upper border of the body for the transit of the 
supra-clavicular nerve.-E. II. Bennett1 records four 
examples of variation in the scapular end of the left 
clavicle, consisting in the extension of the posterior 
border of the bone to or beyond the level of the plane 
of the facet, and in the exhibition of a secondary facet 
which articulates with the spine of the scapula by a 
diarthrodial joint. In two of the instances the scap- 
ula at the acromion was deformed. The region of the 
scapular facet may exhibit in connection with the last- 
named variation the results of mal-nutrition, inflam- 
mation and erosion, as occurred in two bones that 
have come under the writer's notice. In such clavi- 
cles the enlarged, thickened, and deformed parts are 
irregular in form, and bear a strong resemblance to 
formations of old callus, and may be thus mistaken for 
the effects of fracture. It is well to observe that these 
appearances are not seen crossing the bone, but are 
confined to the facet and the parts extending thence 
to the anterior margin of the scapular end.-For varia- 
tions in the lengths of the clavicles, see p. 102.-C. 
Gegenbaur1 describes from the living subject four 
cases of symmetrical absence of the acromial end of 
the clavicle, occurring in a mother and her three 
children. In each case a conspicuous depression ex- 
isted between the shoulder and the front of the chest, 
at the bottom of which the subclavian artery could be 
felt beating. The motions of the scapula appeared to 
he unimpaired. 
The motions of the clavicles are determined by the 
movements of the chest and of the superior extremity. 
Since the union between the clavicle and the scapula 
is nearly fixed, that between the clavicle and the 
sternum and the first rib permits of free motion, and 
causes the thoracic end of the bone to act as a ful- 
crum to the scapula, and through the latter to the 
entire upper extremity. The attachment of the clav- 
icle to the first rib by the antero-inferior lateral facet 
serves, according to G. Hermann Meyer,2 to transfer 
the weight of the superior extremity (as instanced in 
carrying a heavy body on the shoulder or in the hand) 
from the arm and the clavicle to the trunk-the ver- 
tebral column eventually bearing such strain as is 
diffused to it through the manubrium and the first 
pair of ribs. 
The bone when in the position of rest is on the 
same level as the spine of the scapula. In inspiration 
it moves forward an inch. 
The clavicle exerts marked influence over the ap- 
pearance of the neck. As is known, the neck varies 
greatly in apparent length in different individuals; 
this difference, evidently, does not depend upon the 
variations in the measurements of the cervical verte- 
brae, for these are slight, but upon the position of 
the clavicles. In individuals of robust habit and large 
respiratory capacity the clavicles are forced up to a 
higher plane than in those persons of weak muscular 
power, whose respiratory capacity is small.-In the 
corpulent, the subjects of organic heart disease or of 
1 Dublin Journal of Medecine, Ivi. 413, 1873, one instance, fig. 
with scapula ; Ibid. lx. 166, 1875, three instances, one with scap- 
ula, figs. 
1 Jenaische Zeitschr., Bd. I. 1866. 
2 Lehrbuch der Anatomie des Menschen, 104. PLATE XXVll 
Fig. 2 
Fig.l 
T. Sinclair & Son.Lith.. THE UPPER EXTREMITY. 
169 
emphysema, the clavicles are raised and the neck is 
shortened; while in the subjects of phthisis they are 
depressed, the shoulders are sloping, and the neck is 
lengthened. In the full-chested the clavicles pass 
almost horizontally outward; in the narrow-chested 
they incline markedly backward. The last-mentioned 
position of the clavicles is so invariable that it may be 
taken into account in examination for the early stages 
of chronic phthisis.-In a condition which may be 
taken as an average, the median third of the bone an- 
swers to the first rib, which it crosses at an acute 
angle; the middle third to the first intercostal space, 
from which it is separated by the branchial plexus and 
the axillary vessels; and the outer third to the cora- 
coid process and the acromio-clavicular articulation.- 
Enlargements of the subclavian artery and vein can 
in certain abnormal states aid in pushing up the 
clavicle, and together with the other causes already 
mentioned disturb the normal relation of parts at the 
base of the neck. Operations for aneurism or for sub- 
clavian tumors of any kind are from this cause more 
difficult than would appear from the study of the 
comparatively superficial structures met with in the 
subject. Indeed, so great is the difficulty arising from 
the depth at which the artery may lie that division 
of the clavicle has sometimes been resorted to prior 
to ligation of the subclavian artery at its outer 
third.-In cases of comminuted fracture the inter- 
nal jugular vein and the subclavian vein have been 
punctured or compressed. The compression may in- 
volve the subclavian artery, and the pulsation of the 
radial artery may be suspended. Enlargement in the 
volume of the bone is liable to create similarly in- 
jurious pressure. When this is excessive, the expan- 
sion of the chest-wall is so interfered with as to create 
dyspnoea.1-In fracture of the bone at the junction of 
the thoracic end and the body, the former end is fixed 
by the costo-clavicular ligaments, while the remaining 
portion of the bone is depressed by the weight of 
the superior extremity, and the median end is ele- 
vated. In fracture of the body (a result of falling 
upon an outstretched hand) the median fragment is 
raised by the Sterno-Cleido-Mastoid muscle, the late- 
ral fragment is depressed, and the free end drawn 
forward, inward, and backward by the action of the 
shoulder muscles. In the rare fracture -between the 
two divisions of the coraco-clavicular ligament, no 
displacement occurs; but in fracture to the outer side 
of this ligament the lateral fragment is pulled down- 
ward by the weight of the superior extremity until it 
is nearly at a right angle to the rest of the bone, which 
remains in position. 
THE SCAPlTLA. 
The scapula or shoulder-blade (figs. 1, 2, Plate 
XXVII.; fig. 1, Plate XXVIII.) is the main bone of 
the shoulder. It belongs to the class of the flat bones, 
is for the most part thin, and possesses a somewhat 
triangular form. It is situated at the side and at the 
back of the thorax, and when at rest corresponds to 
the distance between the second and the seventh or 
the eighth ribs. The scapula is a very movable bone, 
owing to its connection with the trunk by means of 
the clavicle, and to the numerous powerful muscles 
inserted into it. 
The scapula presents for examination two surfaces, 
three borders, and three angles. The neck, the gle- 
noid cavity, the coracoid process, the spine, with the 
acromion, are also described. 
The dorsal surface (dorsum) is divided*at its upper 
fifth into two unequal portions by the spine. That 
portion above the spine is called the supra-spinous 
fossa, and that below the spine the infraspinous fossa. 
The supra-spinous fossa is concave, and broader toward 
the vertebral than the axillary border. It gives origin 
to the Supra-Spinatus muscle.-The infra-spinous fossa 
is, for the most part, convex for the origin of the 
Infra-Spinatus muscle, but exhibits a longitudinal 
depression toward the robust axillary border. Be- 
low and to the axillary side of the Infra-Spinatus 
impression lies the narrow surface of origin of the 
Teres Minor muscle. Crossing the axillary limit of 
the fossa at its upper third is a transverse groove for 
the dorsal scapular artery. At the inferior narrow 
portion of the infra-spinous fossa, below the surface 
for the last-mentioned muscle, is a smooth triangular 
space for the origin of the Teres Major muscle. This 
is limited above by an oblique line separating it from 
the impression for the Teres Minor. Above the axil- 
lary limit of the Teres Major impression is seen the 
small surface of origin of the Subscapularis muscle, 
which is occasionally present. 
The under surface (venter) extends the entire length 
of the bone. It is concave, and at its upper fifth, viz. 
at the point corresponding in position to the spine 
of the scapula, it presents a somewhat pronounced 
depression, which has received the name of the subsca- 
pular angle. Below this depression, the subscapular 
fossa is marked toward the vertebral border by three 
1 John Britton, British Med. Journ. 1870, 519. 170 
THE BONES. 
or four faint ridges, which serve as points of attach- 
ment for the inter-muscular septae of the Subscapular 
muscle. Along the vertebral border itself is a rough 
line for the insertion of the Serratus Magnus. 
The borders (costae) of the scapula are the upper, 
the vertebral, and the axillary. 
The upper border is thin, and it extends between the 
superior angle and the suprascapular notch, which 
transmits the supra-scapular nerve and vein. To 
the vertebral side of the notch is attached the Omo- 
Ilyoid muscle. 
The vertebral border, (median1 inner, internal, poste- 
rior,) or base, is somewhat thicker than the upper, and 
is divided by the spine into two portions. Holding 
the bone in its natural position, so that the dorsal sur- 
face remains in full view, the portion of the vertebral 
border above the spine inclines upward and forward; 
the portion below the spine inclines downward and 
forward. The supra-spinous border receives the in- 
sertions of the Levator Anguli Scapulae and of the 
Rhomboideus Minor muscles, besides yielding some 
fibres of orjgin of the Supra-Spinatus muscle. The 
infra-spinous border receives the insertion of the 
Rhomboideus Major muscle. 
The axillary border (lateral, external, outer, ante- 
rior) extends from the glenoid cavity to the inferior 
angle, and is remarkably thick as compared to the 
other borders. It is more compressed below than 
above, where its sides are lost on the neck. Directly 
beneath the glenoid cavity, with a slight inclination to 
the ventral surface, is the rough impression (infra-gle- 
noid tubercle) for the origin of the long head of the 
Triceps muscle. Extending thence downward along 
the greater portion of the border is a ridge, which 
serves to separate the impressions for the Infra-Spina- 
tus and the Subscapular muscles. The axillary border 
between the termination of the ridge and the angle is 
occupied by a thin broad spine of varying size, which 
is continuous with the surface on the dorsum for the 
Teres Major muscle. 
The angles of the scapula are the superior, the in- 
ferior, and the glenoid (external). The superior is 
defined by the junction of the upper and the vertebral 
borders ; the inferior by the junction of the vertebral 
and the axillary borders. In examinations of the liv ■ 
ing subject, the inferior angle is from its prominence 
often briefly called the scapular angle. On the dor- 
sum the last-named part of the bone gives origin to a 
slip of the Latissimus Dorsi muscle. The glenoid angle 
(external) is represented by the position of the glenoid 
cavity, and, while essential to the figure of the scapula, 
is less exact than the other angles. Its description is 
included in the account of the neck. 
The neck, unlike the part so named in other bones, 
is the most important division of the scapula when 
viewed from a mechanical point. It constitutes that 
massive portion of the bone which is defined on the 
axillary side by the swollen edge of the glenoid cavity, 
and on the vertebral by the base of the spine. A line 
continued from the last-named point downward to the 
venter would intersect the axillary border at the im- 
pression of the scapular head of the Triceps muscle, 
as a line continued from the same point upward would 
intersect the base of the coracoid process. On the 
venter itself no lines defining the neck exist. A por- 
tion of the neck is, therefore, continuous below the 
spine with the infra spinous fossa, and above the spine 
with the supra-spinous fossa. The neck, as above de- 
fined, is spoken of by some authors as the surgical neck 
(Fig. 69); the anatomical neck, so called, being restricted 
to a line passing round the edge of the glenoid cavity. 
Fig. 69. 
Scapula showing the line of fracture in the Surgical neck. It will be seen 
that the coracoid process and the glenoid cavity are included in the median 
fragment. 
The glenoid cavity (glenoid head) is the surface by 
which the scapula articulates with the humerus. It 
is uniformly concave, and is semicircular at its lower, 
but acuminate at its upper half. Its ventral surface 
is slightly notched on the level with the base of the 
coracoid process. Superiorly, the cavity is continuous 
by an everted surface with the supra-glenoid tubercle 
for the origin of the long head of the Biceps muscle. 
The rim of the cavity is in connection with the glenoid 
ligament, which serves to deepen the articular surface 
during life. 
The coracoid process, so called from its fancied re- 
semblance to a crow's beak, arises as a stout column 
1 The term "median" is in this instance employed by German 
writers, since this border is nearer to the median line of the back 
than the " lateral" (axillary) border is to the median line of the 
sternum. PLATE XXVill 
F1^8^ 
Fig -2 
Fig 1 
T. Sinclair & Son.,lath- THE UPPER EXTREMITY 
171 
from the entire upper border of the neck. It ascends 
on the level of the plane of the neck as far as the 
upper border of the bone, whence it is abruptly de- 
flected downward and forward to end in a narrowed 
tip. Above, the coracoid process is roughened for 
the attachment of the acromio-coracoid and the co- 
raco-clavicular ligaments. Exteriorly it yields a point 
of insertion for the Pectoralis Minor muscle, and of 
origin for the conjoined head of the Coraco-Brachialis 
muscle and the short head of the Biceps. The cora- 
coid process acts as a check to the inward movements 
of the head of the humerus, and unless the process 
be broken subclavicular dislocation can scarcely occur. 
The process is homologous with the coracoid bone of 
batrachians, reptiles, and birds. As seen in these 
animals, the coracoid bone extends between the ster- 
num and the scapula very much after the manner of 
the clavicle in the human subject. 
The spine extends transversely to the plane of the 
dorsum at its upper third. It is of a triangular form, 
its face being outward; it begins by a smooth space 
on a level with the dorsum at the vertebral border of 
the bone (sometimes called the root of the spine), over 
which the Trapezius muscle glides; thence it inclines 
slightly upward as it reaches the region of the neck, 
to terminate abruptly below in a thickened rounded 
edge; above it widens, and is continuous with the 
acromion. The upper surface of the spine is concave 
for the Supra-Spinatus muscle; the lower is inclined 
upward for the Infra-Spinatus muscle. The Trape- 
zius muscle is attached to the edge of the spine above 
and to the Deltoid below. The acromion is the name 
given to the tip of the spine as it overlooks the neck 
of the scapula. The space between the acromion 
and the neck has received the name of the great 
scapular notch. The acromion is a broad flattened 
process deflected toward the coracoid process, the 
plane of whose tip it reaches, and it is curved con- 
centrically to the head of the humerus, which it 
helps to retain in position. The axillary rounded 
border of the acromion is continuous with the lower 
margin of the spine, and gives origin to the middle 
fibres of the Deltoid muscle ; the vertebral border 
(upper, external) is continuous with the upper mar- 
gin of the spine, and is furnished with an oval 
smooth facet for articulation with the clavicle. The 
inclination of this facet upward and backward ac- 
counts for the difficulty of retaining in position the 
scapular end of the clavicle after its dislocation. 
Structure.-The scapula presents the strongest 
arrangement of the cancelli at the neck. The lines 
here radiate from the glenoid cavity toward the ver- 
tebral border. They are intersected by a number of 
laminae that are more or less concentric with the plane 
of the articular surface. When it is remembered that 
no weight is borne by the scapula, the arrangement 
of cancelli of the neck can have relations with forces 
exerted from below only-namely, from the humerus. 
The pressure of the head of the last-named bone against 
the lower half of the glenoid cavity is very great when 
the arm is elevated by the Deltoid and the Supra- 
Spinatus muscles. The object of the cancelli in the 
scapular neck is to receive and distribute through the 
scapula the results of such pressure. Spongy tissue is 
also seen in the coracoid process, acromion, and spine, 
and at the borders and inferior angle of the bone. The 
greater part of the supra- and infra-spinous fossse are 
thin and diaphanous. 
Development.-The scapula arises from eight cen- 
tres of ossification, as follows: one for the body, 
which appears at the eighth week ; one for the cora- 
coid process, which appears at the first year; and one 
for the glenoid cavity, embracing the supra-glenoid 
tubercle. These three centres are primary. The re- 
mainder are accessory centres, and may be thus briefly 
enumerated : one for the base of the acromion, ap- 
pearing at the fifteenth year; one for the tip of the 
acromion, appearing at the sixteenth year; one for 
the base of the coracoid, at the seventeenth year ; one 
for the inferior angle of the bone, at the sixteenth 
year ; and one for the posterior border, at the seven- 
teenth year. The centres for the acromion unite with 
the spine from the twenty-second to the twenty-fifth 
year. The marginal epiphyses unite with the body 
at about the twenty-fifth year. The acromion may 
exist as a distinct bone. In disjunction of the acro- 
mial centre it is not so often the entire acromion as 
it is the portion bearing the facet that is separate.1 
Even in the normally constituted bone the acromial 
centre can be distinguished; inferiorly it is of coarser 
texture than the spine, and everywhere pitted.- 
The coracoid process beyond the plane of the upper 
border of the bone is less frequently seen separated 
than is the acromion. It becomes a very important 
point to distinguish such a condition from fracture 
of the coracoid. While it is true that fracture of 
the process may occur at the point of junction of 
the centre and the base of the process, it is equally 
true that it is not apt to occur-the line of fracture 
1 H. Ruge. Zeitschr. fur rationale Med., 1859, 258. W. Gruber. 
Bull, de l'Acad. de St. Petersbourg, 1859. THE BONES. 
172 
most commonly involving the neck of the scapula, 
with which, as has been shown, the process is con- 
tinuous superiorly.-The centre for the inferior angle 
is sometimes united to the body of the bone by 
synchondrosis. Portal mentions the possibility of 
the detachment of this bone by the violent action of 
the Latissimus Dorsi muscle. 
Remarks.-The variations in the scapula, apart 
from errors of development, are for the most part 
confined to the conversion of the supra-scapular notch 
into a foramen by the ossification of the transverse 
ligament; to the occasional flattening of the venter 
above the subscapular angle; and to the exaggera- 
tion of the spine in the axillary border.-The articu- 
lation between the scapular spine and the clavicle, 
described under the bone last named, is always accom- 
panied with changes in the form of the spine and the 
adjacent parts. Should a specimen of a scapula come 
under notice in which irregular nodosities or ossifi- 
cations are found attached to the upper border of the 
spine near the acromion, the inference is reasonable 
that the clavicle of the corresponding side bad secured 
an articulation to the spine in addition to that of the 
acromion, and that the nodosities were in some man- 
ner associated with such abnormal union. 
The coraco-clavicular ligaments are sometimes ossi- 
fied in whole or in part, and aid in altering the out- 
line of the neck. This occurs either as a result of 
united fracture of the scapular end of the clavicle, or 
as a result of the friction of the coracoid process 
against the clavicle. Under the last-named circum- 
stance an adventitious joint or bursa may be de- 
veloped, about which irregular ossific growths arise. 
Under the action of osteophytes developed about 
the head of the humerus the glenoid cavity and the 
neck may be actually bisected as with a knife. 
The greatest breadth of the scapula is obtained by 
a line extending from the centre of the glenoid cavity 
to the vertebral border ; the greatest length by a line 
extending from the superior to the inferior angle. 
The length of the infra-spinous fossa is obtained by a 
line extending from the vertebral end of the spine to 
the inferior angle. The expression of proportion be- 
tween the breadth and length has received from Broca1 
the name of the scapular index, and the length of the 
infra-spinous line, taken in connection with the other, 
the infra-spinous index. The standards thus accepted 
furnish means of examining scapulse, not only for 
clinical purposes in health and disease, but for all 
other purposes of comparison. 
The general form of the scapula can be made out 
in the living subject; the most easily determined 
features are the spine, the acromion, the vertebral 
border, and the inferior angle. Holden1 suggests that 
measurements of the arms be taken from the junction 
of the spine and the tip of the coracoid process.-The 
posterior surface of the acromion is often separated 
from the skin by a bursa. 
The position of the bone may be precisely stated 
as follows: The scapulse are five and a half inches 
apart at the level of the spines, and six inches at the 
inferior angles. This distance may be lessened in 
muscular subjects; Meckel2 states it at two inches. 
The spine is on a level with the third dorsal spine; 
it about answers to the division between the upper 
and the lower lobes of the lungs, and near the verte- 
bral border is on a level with the third intercostal 
space. 
The motions of the scapula are determined by the 
muscles in connection with it, and by the condition of 
the thoracic wall; and it may be thus thrown out of 
position by muscular atrophy or deformity of the spine. 
The scapulae can be approximated so that the spines 
are an inch and a half apart, and the lower angles 
three inches apart. When widely separated the spines 
are nine inches apart, and the inferior angles thirteen 
inches. When the hands are crossed on the head, the 
inferior angles are sixteen and a half inches apart. In 
inspiration the scapula moves forward one inch, the 
spines are five inches apart, and the inferior angles 
seven inches, while the shoulders assume a square ap- 
pearance. In respiration the scapulae drop slightly, 
and project backward at the inferior angles. These 
projections, when very pronounced, have received at 
the hands of the older writers the name of the scapu- 
lar wings. They are specially noticeable in chronic 
phthisis.3 
Bv the motion of the scapula against the ribs, which 
Henke has somewhat fancifully compared to a ball- 
and-socket joint, a bursa, tursa mucosa intra-serrata, 
is apt to be developed between the concave scapula 
and the convex side of the thorax. Gruber has found 
that in about one-fifth of such instances an elevation 
of cartilage exists upon the third or the fourth ribs, 
over which the scapula glides. Dr. R. Ilcrse4 describes 
clinically a case in which the above condition was 
1 Bulletin de la Soc. d'Anthropologie de Paris, i. (3d series), 
1878, 66 ; also, W. II. Flower, Journ. of Anat, and Phys. xix. 
1879, 13. 
1 Landmarks, 104. 
2 Anatomie, i., 467. 
3 Sibson, Medical Anatomy Col., 45. 
« N. Y. Med. Journ., xiii. 729 THE UPPER EXTREMITY. 
173 
diagnosed. Galvagni1 describes a crepitation accom- 
panying the scapular movements, which is probably 
caused by the rubbing of the bone directly against 
the Serratus Magnus, and indirectly against the ribs. 
The scapula may be excised, and yet the usefulness 
of the arm be preserved. Dr. M. Schuppart2 describes 
such a condition. The motions of the arm while im- 
paired were reasonably efficient. A weight of thirty 
pounds could be lifted and thrown a fair distance. 
THE HUMERUS. 
The humerus (figs. 2 and 3, Plate XXVIII.) is the 
largest bone of the superior extremity. It articulates 
above with the scapula, and below with the bones of 
the forearm. The humerus consists of a head, the 
anatomical and the surgical necks, the greater and 
the lesser tuberosities, the shaft, the epitrochlea, the 
epicondyle, the trochlea, and the radial head. It is 
convenient in addition to use the terms upper and 
lower extremities, which, while not exact, assume the 
bone to be divided into two parts, one above and the 
other below the junction of the upper third with the 
lower two-thirds of the shaft. 
The shaft or body is subeylindrieal above, and in- 
creases in bulk as it approaches the upper extremity; 
it is somewhat prismatic below, is compressed from 
before backwards, and is widened as it reaches the 
lower extremity. 
The head is a large convex surface, which is a little 
longer than wide for articulation with the glenoid 
cavity of the scapula. It represents about a third of 
a sphere, and is directed upward and inward. It is 
bounded at its upper two-thirds by a groove-better 
marked behind than in front-known as the anatomi- 
cal neck. To the outer side of the anatomical neck 
arc two prominences, the greater and the lesser tube- 
rosity. The greater tuberosity (radial tubercle) is 
continuous with the shaft, where it is covered by the 
Deltoid; it is marked on its sides by a number of 
minute pits and foramina, and above by a smooth 
surface obscurely divided by three facet-like depres- 
sions arranged from within outward for the insertion 
of the Supra-Spinatus, the Infra-Spinatus, and the 
Teres Minor muscles. The lesser tuberosity (ulnar 
tubercle) lies to the median side of the former, and is 
covered by the Biceps muscle. It is less abruptly 
separated from the shaft than is the greater, and re- 
ceives the insertion of the Subscapularis muscle. 
Between the tuberosities is a deep, vertical depres- 
sion, the bicipital groove, which advances a short dis- 
tance on the shaft, and receives the long tendon of the 
Biceps muscle.-The line of the lateral (outer) lip of 
the groove corresponds to the median border of the 
greater tuberosity, and also to a ridge that extends 
downward as far as the middle of the shaft. The ridge 
is roughened two inches below the head for the inser- 
tion of the Pectoralis Major muscle, and at its lower 
end by the median boundary of an irregular muscular 
impression (deltoid impression') for the insertion of the 
Deltoid muscle. The deltoid impression itself is a 
large V-shaped space, and lies on the lateral surface 
of the shaft.-The line of the median lip of the bi- 
cipital groove answering to the lateral border of 
the lesser tuberosity is less pronounced than the 
lateral lip. It receives the insertion of the Teres 
Major and the Latissimus Dorsi muscles.-The por- 
tion of the shaft between the insertion of the three 
muscles above named and the head has received the 
name of the surgical neck. At the median (inner) 
side of the shaft, at a point on the level of the inser- 
tion of the Deltoid muscle, is a faint and narrow im- 
pression for the insertion of the Coraco-Bracliialis 
muscle. Immediately beneath the lateral border of 
the deltoid impression, and extending thence from be- 
fore backward, is the spiral groove, for the musculo- 
spiral nerve and the superior profunda branch of 
the brachial artery. The posterior surface of the 
shaft below the line of the groove is smooth and nearly 
flat, for the origin of the internal head of the Triceps 
muscle. The anterior surface below the deltoid im- 
pression is abruptly convex, more markedly so above 
than below, for the origin of the Brachialis Anticus 
muscle. Separating the anterior from the posterior 
surfaces are two vertical ridges: the outer, the supra- 
condyloid ridge (supinator ridge), extends from the 
spiral groove to the epicondyle; the inner, the supra- 
trochlear ridge, extends from the insertion of the 
Coraco-Brachialis muscle to the epitrochlea. Both 
these ridges serve to give attachment to inter- 
muscular septse. The foramen for the nutritious 
artery (nutritive artery) of the shaft is seen at the 
upper end of the supra-trochlear ridge, with its orifice 
directed upward. 
The trochlea is a cylindroid articular surface, placed 
transversely to the axis of the bone, and depressed in 
the centre; it articulates with the greater sigmoid 
notch of the ulna. The trochlea is broader and 
deeper behind than in front, and is inclined slightly, 
so that the middle of the upper trochlear margin in 
front lies to the median (inner) side of the axis of 
1 Stricker's Medecin. Jahrbuch. 1873, ii. 
2 New Orleans Journal of Medicine, Jan. 1870. 174 
TIIE BONES 
the humerus, while behind it is inclined to the lateral 
(outer) side. The trochlea is more sharply defined 
medianly than laterally. It is simple and concave 
behind, but presents in front, in addition to a central 
concavity, a convexity toward its median side. To 
the lateral side of the trochlea, and separated from 
it by a groove, is a well-defined convex surface, the 
radial head (condyle, capitcllum), for articulation with 
the depression on the head of the radius. It is di- 
rected forward, and is confined to the anterior aspect 
of the bone. 
Above the trochlea in front is a shallow triangular 
depression for the coronoid process of the ulna. A less 
distinct impression is seen above the radial head. 
Directly above the trochlea behind is a broad deep 
depression for the olecranon. To the lateral (outer) 
side of the radial head is a depression for the exter- 
nal lateral ligament; above it is seen a conspicuous 
tubercle-the epicondyle (external condylar eminence), 
for the origin of the extensor muscles of the forearm. 
To the median (inner) side of the trochlea is a pro- 
cess corresponding to the foregoing, but much more 
conspicuous than it-the epitrochlea (internal condylar 
eminence). This is roughened at the tip for the attach- 
ment of the internal lateral ligament of the elbow- 
joint, and in front for the origin in great part of the 
flexor muscles of the forearm.-The region of the 
epicondyle is much thicker than that of the epitroch- 
lea ; in some morbid conditions the disproportionate 
thickness between the two becomes enormously exag- 
gerated. 
Structure.-At the head are presented two sets of 
lines, a median and a lateral. The median set is com- 
posed at its outer border of nearly vertical lines, which 
pass downward from the upper border of the head to 
the median border of the anatomical neck. The inner 
members of this series become curvilinear and shorter 
as the lower border of the articular surface is reached. 
Thus the first of the central lines are the longer, and 
the last the shorter.-The outer set is composed for 
the most part of vertical lines passing through the 
greater tuberosity to the lateral wall of the anatomical 
neck. The median laminae of this set become more 
and more oblique, and finally intersect the lateral fibres 
of the inner set. 
At the distal end the laminae, when seen in trans- 
verse longitudinal (frontal) section of the bone, are 
nearly vertical at the centre, but are moderately con- 
cave at their nearest border at the sides. Near the 
position of the epicondyle and epitrochlea are a num- 
ber of oblique lines. In the longitudinal antero- 
posterior (sagittal) section lines are seen to converge 
from the articular surface to the compressed layer 
between the olecranon fossa and the depression for 
the coronoid process of the ulna.-In addition to the 
above arrangement the epiphysis can be distinguished 
from the shaft by the fine texture of the cancelli 
lying beneath the articular surface, and by the coarse 
and for the most part vertically arranged laminae of 
the greater tuberosity. In some specimens the two 
sets of the shaft, instead of being straight, are slightly 
curved toward each other.-Notwithstanding the 
strength of the humerus, numerous examples are on 
record of its fracture by muscular action.1 
Development.-The humerus arises from seven to 
eight centres of ossification. The first centre appears 
in the shaft at about the eighth week ; the nucleus for 
the head appears at the second year, and that for the 
great tuberosity at the third year. The lesser tube- 
rosity, should it have a distinct centre, ossifies at the 
fifth year. The centres above named coalesce by 
the fifth year, and constitute the upper or proximal 
epiphysis. The union between it and the shaft takes 
place at about the twentieth year. The radial head 
is the first portion of the distal end of the bone that 
ossifies, since it receives its centre at the third year. 
The remaining parts ossify in the following order: 
the epitrochlea at the fifth year, the trochlea at the 
eleventh or the twelfth year, and the epicondyle at 
the eighteenth year. The distal end when completed 
unites with the shaft at about the sixteenth or the 
seventeenth year. 
A transverse line drawn below the tuberosities de- 
fines the distal limit of the proximal epiphysis, as a 
similar line uniting the proximal borders of the epi- 
trochlea and the epicondyle defines the proximal limit 
of the distal epiphysis. Both of the epiphyses may 
be violently detached in the living subject (Fig. 70). 
In the event of the proximal epiphysis becoming de- 
tached, it has been found by Mr. Jno. Hutchinson2 
that the periosteum is apt to be stripped off from the 
proximal end of the distal fragment of the shaft, and 
left attached as a dense cup to the distal edge of the 
proximal one. This circumstance leaves the epiphysis 
with more muscular fibres attached to it than would 
have been the case were a clean section made through 
the bone and the periosteum. Thus, the Teres Minor 
muscle is inserted distally to the ephiphyseal line, but 
1 Hamilton on Fractures and Dislocations ; and W. Parker, N. 
Y. Journ. Med., 1852, 95. 
2 Med. Times and Gazette, 1866, 248. THE UPPER EXTREMITY 
175 
is nevertheless apt to remain with the periosteum 
belonging to the proximal fragment.1 The distal epi- 
physis may be detached entire, or the mass composed 
of the radial and trochlear centres may remain in 
ward, and the bone about the angle is sometimes 
thicker and rougher than is the rule. The last-named 
appearance, when taken in conjunction with the appa- 
rently bent shaft, has caused these specimens to be 
confounded with others that show effects of fracture. 
No mistake of this kind need be made if the side 
opposite to the angulation be examined. Should the 
specimen be one of old fracture, the opposite side 
will be uneven, while it is quite smooth in the variety 
of the normal bone just mentioned. The surface of 
origin of the third head of the Triceps muscle is often 
convex instead of flat, and may be the seat of localized 
ostitis.-The bases of the depressions for the olecranon 
and the coronoid processes may communicate with 
each other. 
Under the name of the supra-condyloid process is 
described as a rare anomaly a slender process pro- 
jected from the median border of the bone above 
the internal condyle (epitrochlea). It is supposed to 
be a rudiment of an osseous bridge that defines a 
foramen seen in this position in some quadrupeds, 
as in the dog and the raccoon. The Pronator Radii 
Teres muscle may arise by means of a thin fibrous 
band from this process.1 
The shape of the humerus can be with relative ease 
defined under the skin. Among the more conspicuous 
points may be mentioned the greater tuberosity, the 
general direction of the bicipital groove, the epitroch- 
lea, and the epicondyle. The fingers, pushed well 
up into the axilla, will be found to reach the shaft at 
the surgical neck. This method of examination is 
facilitated by a moderate degree of elevation of the 
arm. 
According to Holden, it is just below the insertion 
of the Deltoid that ununited fracture of the shaft is 
seen, partly on account of the injury to the nutritious 
artery here situated, and partly on account of the 
action of the Deltoid muscle in causing a riding of 
the proximal fragment over the distal.-Old persons 
not infrequently suffer from fracture high up through 
the tuberosities, just as they are liable to fracture of 
the neck of the thigh-bone, and of the cancellous 
structure at the base of the trochanter.2 
Exostoses have been seen occupying the position 
of insertion of the Pectoralis Major, the third head 
of the Triceps at its upper part, and the insertion of 
the Latissimus Dorsi. When such outgrowths occur, 
the portion of the shaft below the anatomical neck is 
Fig. 70. 
Humerus showing separation of the proximal epiphysis. 
connection with the shaft, and either the epicondyle 
or epitrochlea be detached. Luschka mentions an 
example of the former in which the centre, while 
detached, still retained a quasi connection with the 
shaft by cartilage. 
Remarks.-The bones of the superior extremity 
are generally described as though the forearm and 
the hand were strongly supinated. This position so 
places the humerus that its deltoid surface moves 
from an anterior to a lateral (external) position, and 
its bicipital from a median (internal) to an anterior. 
The physician, however, will rarely be required in 
making examinations to place the limb in this unusual 
position. It is advisable that the bones should be 
studied as they are seen in the position of rest, namely, 
with the hand and forearm pronated. Thus seen, the 
deltoid surface of the humerus is directed forward 
and slightly outward, and the bicipital groove forward 
and slightly inward. The lower extremity is not at 
a right angle to the axis of the trunk, but hangs 
obliquely so that the epicondyle is on a plane in front 
of the epitrochlea. 
The varieties in the shape of the humerus are not 
numerous. One of the most striking is an angula- 
tion of the shaft at the position of the insertion of 
the Deltoid muscle, and at first sight it appears to be 
the result of this muscle's traction on the bone. The 
shaft above the angle is directed inward and back- 
1 For literature and figures, see W. Gruber, Mem. Acad, of St. 
Petersburgh, 1859, 55 ; also, Jno. Struthers, Edin. Med. Journ., 
1848, and Lancet, 1863, i. 87. 
2 Jno. Hutchinson, Med. Times and Gaz., 1866, 303. 
1 Jno. Hutchinson, Med. Times and Gaz., March 10, 1866, 248. 176 
THE BONES. 
remarkably inflated. Exostosis of the greater tube- 
rosity has been successfully removed by operation.1 
The head of the bone has been known to be absorbed, 
as recorded in a case by Bull.2 
THE ULNA. 
The ulna (fig. 4, Plate XXIX.) is the longer of 
the two bones of the forearm. It articulates proxi- 
mally with the trochlea of the humerus, distally with 
the carpus, and at the lateral side with the radius. 
It lies to the median side, and to some extent behind 
the radius. A line drawn downward through the 
radial head of the humerus would touch the lower 
end of the ulna. 
The ulna is divided into a shaft, an upper and a 
lower extremity. 
The upper extremity is of an irregular quadrilateral 
figure, deeply notched above to form the greater sig- 
moid cavity. The posterior limit of the notch forms 
the olecranon, and the anterior the coronoid process. 
The olecranon is continuous with the shaft poste- 
riorlv. It forms a massive process, curved slightly 
forward, and is wider in front than behind. Its pos- 
terior surface is rounded for the insertion of the ten- 
don of the Triceps muscle, while the summit is for 
the most part smooth for the accommodation of a 
large synovial bursa. A narrow groove between the 
site of the bursa and the free edge designates the line 
of attachment of the posterior and the lateral por- 
tions of the capsular ligament. Beneath the insertion 
of the tendon of the Triceps muscle is a free triangu- 
lar surface, with the apex directed distally; the sides 
are defined by the approximation of the Anconeus 
and the Extensor Carpi Ulnaris muscles; it consti- 
tutes the portion of the bone felt beneath the skin in 
the undissected subject. 
The coronoid process is continuous with the front of 
the ulna. It is a wide, compressed projection, having 
a broad base, and well-defined sides. Its anterior sur- 
face is flat or slightly concave, to receive, by a rough 
impression toward the median side, the tendon of the 
Brachialis Anticus muscle. At the base of the coro- 
noid process is a slight elevation termed the tubercle 
for attachment of the oblique ligament. The line of 
junction at the median side between the coronoid 
process and the olecranon is depressed to give origin 
in part to the Flexor Carpi Ulnaris muscle, and to a 
slip of the Flexor Sublimis Digitorum. The lateral 
side of the coronoid process is depressed, and marked 
at the upper half by an elliptical concave articular 
surface-the lesser sigmoid cavity-for articulation 
with the head of the radius. The bone on either side 
of this facet is often roughened for the attachment of 
the orbicular ligament. Below the lesser sigmoid 
cavity the lateral surface is abruptly concave for the 
origin of a slip of the Supinator Brevis muscle. 
The greater sigmoid cavity in articulating with 
the trochlea of the humerus presents for exami- 
nation two surfaces, one pertaining to the olecranon 
and the other to the coronoid process. These sur- 
faces are separated by a transverse groove, which, 
beginning conspicuously at the middle of the median 
border, ends faintly at the corresponding point on 
the lateral border. At a right angle to this notch 
is a smooth vertical ridge which extends from the 
centre of the upper margin of the olecranon above to 
terminate at the anterior free margin of the coronoid 
process below, and which serves to divide the sigmoid 
notch into two unequal areas ; of the^e areas the inner 
is the larger and more concave. 
The shaft of the ulna is three-sided, and presents 
accordingly three surfaces for examination, an ante- 
rior, a posterior, and a median (inner). The anterior 
and posterior surfaces are sharply separated by a thin 
compressed ridge, which is well defined along the 
middle third of the lateral border, and which serves 
for the attachment of the interosseous ligament. The 
median (inner) surface is joined to the anterior by a 
rounded border, having imperfectl defined limits. 
The posterior surface is continuous with the anterior 
surface, excepting at its middle third, where it is sepa- 
rated by the ridge above named. 
The details of the shaft, as ir^ ided within the 
above-named borders and surfaces, are as follows : the 
anterior surface exhibits a longitudinal depression, for 
the origin of the Flexor Profundus Digitorum, ex- 
tending downward and outward from the insertion of 
the Brachialis Anticus. The oblique line serves to 
separate the surfaces of origin of the Supinator 
Brevis from the Flexor Sublimis Digitorum; near 
this line, and toward the median border of the shaft, 
is seen the nutritious foramen directed from the upper 
extremity of the bone. Toward the distal extremity 
the anterior surface becomes narrower, and is marked 
by a line directed downward and inward, for the ori- 
gin of the Pronator Quadratus. The posterior surface 
is limited laterally above by an oblique line or ridge, 
extending from the posterior border of the lesser sig- 
moid cavity downward and outward to separate the 
depression for the insertion of the Anconeus muscle 
1 Lancet, 1864, 210. 
2 Med. Times and Gaz., 1868, 498. PLATE XXIX 
Fig .4. 
3 
Fig s 
E i g 1 
T.Sinclair ason.li^ Phila THE UPPER EXTREMITY. 
177 
from the ulnar origin of the Supinator Brevis. To this 
succeeds a longitudinal ridge, whose hinder surface is 
slightly concave for the origin of the Extensor Carpi 
Ulnaris muscle. The outer, lower, and rougher parts 
of the posterior surface give origin to the extensors 
of the thumb, and in part to the Supinator Brevis 
muscle. The median border of the posterior surface is 
for the most part smooth and convex, being broad and 
concave at its upper portion for origin of the Flexor 
Profundus Digitorum. It is subcutaneous at its lower 
fourth. 
The lower extremity of the ulna is sub-cylindrical in 
form, and concave on its anterior surface for the Pro- 
nator Quadratus muscle. The apparent constriction 
at this point has received the name of the neck of the 
ulna. The posterior surface is slightly concave for 
the tendon of the Extensor Carpi Ulnaris muscle. Its 
median surface is narrow, rounded, and produced 
posteriorly below the level of the main articular sur- 
face, and receives the name of the styloid process, and 
to it is attached the external lateral ligament of the 
wrist-joint. The tip of the process is covered with 
cartilage, and forms a constituent part of the joint. 
The articular surface of the lower extremity of the 
ulna is termed the head. It presents a rounded, nearly 
vertical lateral border, for articulation with the sig- 
moid cavity of the radius, and is continuous with the 
distal surface which is in apposition with the triangu- 
lar cartilage of the wrist-joint, attached to the notch 
between the articular surface and the styloid process. 
Structure.-The proximal end of the ulna pre- 
sents a somewhat complex arrangement of laminae. 
First in order is a series of nearly vertical lines ex- 
tending from the great sigmoid fossa to the anterior 
surface of the shaft. Second, a small group of lines 
concentric with the curvature of the great sigmoid 
cavity at its lower half. Third, a series of scattered 
lines covering the olecranon obliquely from behind for- 
ward and downward. Fourth, numerous intersecting 
arching lines in the remainder of the extremity. The 
distal end is occupied by oblique, scarcely intersecting 
lines arranged as in the corresponding end of the 
radius. 
Development.-The ulna arises from three centres 
of ossification. The nucleus for the shaft appears at 
about the eighth week ; that for the lower extremity 
at the fourth or fifth year. The upper extremity, so 
far as it is articular, is an outgrowth from the shaft. 
An epiphyseal nucleus appears at the tip of the ole- 
cranon at the tenth year. This joins the shaft about 
the seventeenth year. The lower epiphysis unites 
with the shaft about the twentieth year. 
The distal epiphysis has been frequently separated 
by violence, and in some instances has been necrosed 
and lost. It is interesting to know that a useful arm 
may result after this singular lesion. The olecranon 
and the coracoid process very rarely persist as distinct 
bones. 
Remarks.-The shaft of the ulna is often obliquely 
deflected at the oblique line.-The olecranon is some- 
times broken by a fall on the elbow, the fracture 
generally taking place at the constriction where the 
process joins the shaft-thus involving the joint. 
The coronoid process may be broken off by excessive 
strain of the Brachialis Anticus muscle. Liston men- 
tions a case of this kind occurring to a boy eight 
years of age, in consequence of hanging with one 
hand from the top of a high wall. Fractures of the 
olecranon and the coracoid process unite, as a rule, by 
ligament. 
When the ulna and the radius are in articulation, it 
is noticed that the styloid process of the former is 
somewhat shorter than that of the latter. Both it 
and the ulnar head can be made out in the undissectcd 
subject, lying between the Extensor Carpi Ulnaris 
and the Extensor Minimi Digiti muscles. 
A sesamoid bone is rarely found lying in front of 
the coronoid process. In a case reported by Fischer,1 
it attained the size of a pigeon's egg. 
THE RADIUS. 
The radius (figs. 1, 2, 3, Plate XXIV.), while slightly 
shorter than the ulna, is more massive than that bone, 
and articulates with the radial head of the humerus 
above, the carpus below, and the ulna at its median 
(inner) side in such a manner as to secure movements 
that are much more varied than are those of the ulna. 
The part the radius contributes to the formation of 
the elbow-joint is small compared to that which it 
contributes to the wrist. 
The radius consists of a shaft and an upper and a 
lower extremity. The bone is narrow and irregularly 
rounded above, broader and somewhat three-sided 
below. The upper extremity is termed the head. It 
is disk-shaped, with a depression above, as already 
mentioned, for articulation with the radial head of the 
humerus. The depression does not occupy the entire 
proximal facet, for at its inner side a crescentic con- 
1 Langenbeck's Archiv fur Chirurg., 1871, xii. 863, figs. 9 anti 
10, tab. 15. 178 
THE BONES 
vexity is seen which articulates with a groove be- 
tween the radial head and the trochlea. The head 
presents vertical borders, which arc more pronounced 
within than without, for articulation with the lesser 
sigmoid cavity of the ulna, and the orbicular liga- 
ment. Below the head is a circular constriction- 
the neck. Directly beneath the neck at its anterior 
surface is the large rounded prominence-the tube- 
rosity-the front aspect of which is smooth for the 
accommodation of a bursa, while the back part is 
roughened for the insertion of the tendon of the 
Biceps muscle. ThesAq/7of the radius seen from the 
outer side at the position of the tuberosity is flattened 
and covered by the Supinator Brevis muscle. 
Extending from the position of the tuberosity down- 
ward and outward as far as the outer surface of the 
shaft at about its middle is the oblique line. A little 
below the end of this line lies the roughened impres- 
sion for the insertion of the Pronator Radii Teres. 
Thence to the distal end the shaft is somewhat three- 
sided. The median edge or border is sharp and com- 
pressed for the attachment of the interosseous liga- 
ment. The lateral surface or border is broad and 
convex, and covered by the tendon of the Supinator 
Longus muscle. The anterior surface is nearly smooth, 
and marked for the upper two-thirds by the origin 
of the Flexor Longus Pollicis muscle, and below (near 
the wrist) for the insertion of the Pronator Quadratus 
muscle. A short distance below the oblique line at 
the upper third of the shaft is the nutrient canal, the 
orifice of which is directed upward. The posterior 
surface is nearly plane, and covered with the Extensor 
Communis Digitorum. 
The loxver extremity is larger than the upper. It is 
somewhat irregularly quadrangular, and marked by 
the anterior, the lateral, the posterior surfaces (which 
represent corresponding surfaces of the shaft), and the 
median (inner) surface which is continuous with the 
median edge of the shaft.-The anterior surface is 
slightly concave, with sharply defined borders.- Its 
Ynedian (ulnar) half projects a little forward, and 
answers to the semilunar bone; while the lateral 
(outer) half is deflected downward and outward to 
form the anterior surface of the styloid process, serves 
for the attachment of the capsular ligament of the 
wrist-joint, and answers to the scaphoid bone.-The 
lateral (outer) surface is broad, and defined in front 
by the sharp edge separating it from the anterior 
surface-and behind by a ridge, which is confined for 
the most part to the shaft, and terminates abruptly 
a short distance from th.e articular surface, and which 
separates the tendons of the extensors of the fingers 
from the tendons of the extensors of the carpus. The 
lateral surface is further distinguished by a central 
ridge confined for the most part to the epiphysis. It 
passes along the entire length of the styloid process, 
and separates the groove for the extensor of the 
metacarpal bone of the thumb, and of the first joint 
of the thumb, from the extensors of the carpus.-The 
posterior surface is generally described as included 
within the former.. It is limited to that portion of 
the bone lying between the median and the lateral 
surfaces. It is nearly smooth, and occupied by the 
tendons of the extensors of the fingers, and marked at 
its outer border by a special groove (sometimes absent) 
for the Extensor Indicis muscle.1-The median (inner) 
surface is of a triangular shape, narrow above where 
it is continuous with the inner edge of the shaft, 
broader below where it joins the carpal surface at a 
right angle-and presents a facet called the siymoid 
cavity, which is concave to articulate with the head of 
the ulna. 
The distal or carpal articular surface is concave, 
and triangular in form, its base being directed to the 
median side. Its antero-posterior diameter is marked 
by a faint ridge which separates the lateral triangular 
facet for articulation with the scaphoid bone from the 
median more quadrangular facet for articulation with 
the semilunar bone. 
Structure.-The direction of the laminae is such 
that the lines pass downward somewhat convergingly 
from the proximal articular surface to the inner side 
of the neck. These are intersected so as to form nar- 
row arch-like figures by lines starting from the sides 
of the bone. In the distal extremity the lines are 
oblique and, as such, pass downward from each side 
to the epiphyseal end, where they terminate with little 
or no intersection. The lines are more vertical at the 
outer border. A number of transverse lines are seen 
in the epiphysis.-In aged subjects the distal epiphy- 
seal end becomes much weakened by reason of the 
partial atrophy of the cancelli. As a result fracture 
has not infrequently resulted in comminution of the 
distal end and inevitable shortening of the shaft of 
the bone. 
Development.-The centre for the shaft of the 
radius appears between the fifth and the eighth 
week. The centre for the lower extremity appears at 
the second year, and unites with the shaft at the 
twentieth year. The centre for the upper extremity 
1 A portion of the lateral surface is seen in connection with the 
posterior when the bone is viewed from behind. THE UPPER EXTREMITY. 
179 
(head) appears at the fifth year and unites with the 
shaft about puberty. 
Remarks.-The shaft of the radius may be deflected 
inward at the pronator impression. 
The position of the radius can be determined in 
the undissected subject by the shaft. With careful 
manipulation the tubercle can be made out in forced 
pronation, while the styloid process and the lateral 
surface of the inferior extremity can be readily out- 
lined. The advantage secured by defining this surface 
as distinct from the posterior is decided in studying 
the relation of the parts at the wrist. The lateral 
surface is easily detected beneath the skin, and the 
tendons of the pollical and the carpal extensors can 
be felt as the thumb and the hand are extended. 
The posterior surface in the subject cannot be limited 
medianly, but is bounded by the head of the ulna. 
The application of these facts in regional anatomy to 
the study of the lesion of Barton's fracture is so 
direct as to require no comment.-Surgical writers 
describe a depression on the lateral side of the ole 
cranon, which answers to the head of the radius.-J. 
Kaczande1 narrates an instance of congenital absence 
of the radius. 
THE CARPUS. 
The carpus (Plate XXX.) is a system of irregular 
bones placed between the bones of the forearm and 
the metacarpus. It is composed of eight bones, 
enumerated from the radial to the ulnar border, 
as follows: the scaphoid, semilunar, cuneiform, pisi- 
form, trapezium, trapezoid, os magnum, and unciform. 
The figure of the carpus is broader than long, and 
slightly curved upon itself. It presents a slightly 
convex dorsal surface, and a concave palmar surface, 
which is deepened by lateral pressure-the tuberosity 
of the scaphoid, an oblique process of the trapezium 
lying at the lateral border, and the hamular process 
of the unciform at the median. Between these promi- 
nences the deep annular ligament is stretched. The 
proximal surface is smaller than the distal, and is 
convex for articulation with the radius and the 
triangular ligament. The distal surface is slightly 
curved downward, and, excepting a small surface of 
the trapezium between the first and second meta- 
carpals, which is free, is designed for union with the 
metacarpus. 
The bones of the carpus are arranged in two rows, 
named, from the proximal to the distal end, the first 
and the second row. The first row is composed of the 
scaphoid, semilunar, cuneiform, and pisiform bones; 
the second row, of the trapezium, trapezoid, os magnum, 
and unciform. Of these the pisiform alone presents 
but a single facet. The pisiform is the least important 
of the carpal bones, and pertains more properly to the 
muscles on the ulnar border of the forearm and hand. 
The line between the two rows is called the inter- 
carpal. line. 
The bones of the first row are so articulated as to 
yield an arch extending transversely. This is concave 
below, opposite the three outer fingers, in such a way 
as to secure the scaphoid and the cuneiform bones on 
the sides of a curve of which the semilunar bone 
is the centre, and which receives the convexity formed 
by the unciform bone and the os magnum. 
Toward the radial border the first row presents a 
convex lateral surface confined to the scaphoid bone, 
which is received into a concave surface composed of 
the distal facets of the trapezium and the trapezoid 
bone. Thus the inter-carpal line is sinuous; it is 
curved forward for the carpal bones, answering in 
position to the thumb and index finger, and backward 
for those answering to the middle, the ring, and the 
little finger. 
The bones composing the carpus are free for liga- 
mentous and muscular attachment on the palmar and 
dorsal surfaces; they are faceted on the remaining 
sides, except at their entrance into the radial and 
ulnar border, where they are also free. 
Structure.-Each bone is composed of cancelli, 
with a thin outer compact layer. 
Development.-Each carpal bone arises from a 
single centre of ossification.1 The os magnum ossifies 
at the first year; the unciform at the second; the 
cuneiform at the third ;■ the trapezium and the semi- 
lunar bones in the fifth; the scaphoid in the sixth 
and seventh ; the trapezoid in the seventh or eighth; 
and the pisiform at the twelfth year. 
The motions of the carpus as a whole are limited 
to the radio-carpal joint. The second row is capable 
of being moved upon the first-as in the act of creep- 
ing. Here the portions of the hand supporting the 
weight of the body-viz., the phalanges, the meta- 
carpus, and the second row of carpal bones-are ex- 
tended upon the first row, which remains in direct 
1 For the statement that the carpal bones may arise from more 
than one centre each, see Rambault and Renault, Origins et Deve' 
loppement des Os. Paris, 1867. 
1 Virchow's Archiv, 1877, 409. 180 
THE BONES. 
line with the vertically placed bones of the forearm. 
The carpus for the main features of its mechanism 
is best studied in the act of transmitting the shock 
received through all the bones from the distal to the 
proximal ends. Thus, in striking with the fist, the 
force of the blow is received by the distal ends of 
the outer four metacarpal bones, through the flexed 
base of the first row of the phalanges. It is thence 
transmitted along the bones of the forearm (notably 
the radius) by means of the convergent axial lines of 
the carpal bones. Animals walking upon the ends of 
the toes, such as ruminants, horses, and others, retain 
the disto-proximal mechanism of the carpus still more 
conspicuously than does man. 
The Scaphoid Bone.-The scaphoid bone (navicu- 
lar bone) is the first bone of the first row. It articu- 
lates with the radius proximally, with the trapezium 
and the trapezoid distally, and with the os magnum to 
the ulnar side. The proximal surface is pyriform, the 
base being directed medianly, and lying in the palmo- 
dorsal axis of the bone; the distal surface is broader 
toward the palm than is the dorsum. Between the 
last-named surfaces a groove extends, which consti- 
tutes the dorsum of the bone, and is continuous with 
the radial border. The ulnar surface is crescentic and 
convex above for articulation with the semilunar 
bone, and oblong and concave below for articulation 
with the os magnum. The radial border is free and 
roughened for the attachment of the internal lateral 
ligament at the scaphoid tubercle, which can be distin- 
guished during life lying to the median side of the 
extensors of the thumb. 
The Semilunar Bone.-The semilunar bone is 
placed between the radius proximally, and the os 
magnum and the unciform bone distally; the scaphoid 
bone lies to the radial border, and the cuneiform to 
the ulnar. The proximal surface, which is triangular 
in form, with the base directed toward the radial 
border, and the dorsal angle produced, is convex for 
articulation with the quadrilateral facet of the distal 
end of the radius. The distal border is bi-faceted- 
the radial facet being concave for articulation with the 
os magnum, and the ulnar facet (often inconspicuous) 
being flat and narrow for articulation with the unci- 
form bone. Both the dorsal and the palmar surfaces 
are free, the palmar being the larger of the two. Of 
the lateral surfaces of the semilunar bone the radial 
is crescentic in form, and smooth for articulation with 
the scaphoid bone, the ulnar is flat and oblique for 
articulation with the cuneiform. 
The Cuneiform Bone.-The cuneiform bone, as 
its name implies, resembles a wedge, with its base 
directed toward the radius. The largest articular 
surface-the distal-is saddle-shaped, broader above 
than below, and articulates with the unciform bone. 
A line carried back from it leads to a free dorso- 
lateral surface for the attachment of the external lateral 
ligament of the wrist joint. There is thus no proper 
proximal surface of the bone. The dorsal surface is 
roughened for the ligamentous attachment at the 
ulnar half of the bone, but is convex and smooth for 
articulation with the fibro-cartilage of the wrist-joint. 
The palmar surface is irregular and roughened for 
attachment of ligaments. The radial surface presents 
a smooth facet for articulation with the semilunar 
bone; the ulnar is small, oval, smooth for articulation 
with the pisiform bone; a groove lies between facets 
of articulation with the pisiform and the unciform 
bones. 
The outline of the bone can be made out in the 
undissected subject. 
The Pisiform Bone.-The pisiform bone lies to 
the ulnar margin of the first row of the carpus on its 
palmar surface. It presents a single articular facet 
for the cuneiform bone, and lies to the ulnar side of 
the first row of carpal bones. The proximal, the 
distal, and the ulnar surfaces are free, receive the 
tendon of the Flexor Carpi Ulnaris muscle, and afford 
attachment to the external lateral ligaments of the 
wrist-joint. The bone also presents a facet for the 
Abductor Minimi Digiti muscles, and gives attach- 
ment to the anterior annular ligament. 
The position of the pisiform bone can be easily re- 
cognized during life. 
The Trapezium.-The trapezium is placed in front 
of the radial half of the distal surface of the scaphoid 
bone and proximally to the first metacarpal bone. It 
presents a distal saddle-shaped surface for articula- 
tion with the first metacarpal bone, and a proximal 
concave facet for articulation with the scaphoid bone. 
The dorsal surface is free, and exhibits two prominent 
tubercles in front, with an intermediate depression. 
The palmar surface is the most characteristic, and is 
marked by a wide compressed oblique process, for the 
origin of the Abductor Pollicis and the Flexor Brevis 
Pollicis muscles, and for the attachment of the deep 
annular ligament, as well as by a groove placed dorsally 
to the above-named process, for the tendon of the 
Flexor Carpi Badialis muscle as it passes to its inser- 
tion on the second metacarpal bone. PLATE XXX 
FiL 2 
^.1 
T Sinclair 4Son, liSi.rKIa TIIE UPPER EXTREMITY. 
181 
Of the remaining surfaces, the radial is free and 
smooth, the ulnar is faceted for articulation with the 
trapezoid and the second metarcarpal bone. Between 
the distal facet and the ulnar border is a small portion 
of the trapezium, which lies free between the first and 
the second metacarpal bones, and serves for the attach- 
ment of a ligament. 
Holding the bone with the grooved side downward, 
the saddle-shaped facet will point to the side to which 
the bone belongs. 
The Trapezoid Bone.-The trapezoid bone is 
placed between the radial half of the scaphoid bone 
proximally and the second metacarpal bone distally. 
It is narrow on the palmar surface, presents a nearly 
quadrilateral shape through the body, but is broad 
and irregular on the dorsal surface. The proximal 
surface is narrow, and yields a slightly concave facet 
for articulation with the scaphoid bone. The distal 
surface is saddle-shaped, with a median ridge, and 
articulates with the second metacarpal bone. The 
dorsal pentagonal surface is smooth and free, as is 
also the palmar. The radial surface articulates with 
the trapezium, and the ulnar with the os magnum. 
The Os Magnum.-The os magnum is placed be- 
tween the semilunar bone and the ulnar surface of the 
scaphoid on its proximal side, and the third meta- 
carpal bone on its distal side. The trapezoid and a 
portion of the second metacarpal lie to its radial, and 
the unciform bone to its ulnar side. The distal surface 
is triangular, and is concave for articulation with the 
third metacarpal bone. The proximal end forms the 
head of the bone; it is sub-rounded in form, and con- 
vex for articulation with the semilunar bone. The 
head is convex on its radial side, but flat on the ulnar, 
and is more conspicuous on the dorsal than on the 
ventral surface. The dorsal surface is marked by 
the facet for the semilunar bone proximally, but is 
broader and more irregular distally. The palmar sur- 
face is free, narrow, and convex. The radial surface 
constitutes a convex facet for articulation with the 
scaphoid; and a small median surface presents a facet 
for the trapezoid. The ulnar surface presents a facet 
along the entire length of the dorsal half of the bone for 
articulation with the unciform bone, while the palmar 
half is flat and roughened for ligamentous attachment. 
The Unciform Bone -The unciform bone is placed 
between the semilunar and the cuneiform bones proxi- 
mally, and the fourth and the fifth metacarpal bones 
distally. The distal surface presents a large articular 
surface divided by a ridge into facets, as follows: the 
facet to the radial side of the ridge articulates with 
the fourth metacarpal bone, that to the ulnar side 
with the fifth metacarpal bone. The proximal surface 
is very oblique, and occupies the entire width of the 
bone. It is concave toward the ulnar side, convex 
toward the radial. A faint ridge defines the two 
facets: the first is very small, narrow, and convex 
at the radial edge for articulation with the semilunar 
bone; the second is large and, for the most part, con- 
cave for articulation with the cuneiform bone. The 
palmar surface is very irregular, and is marked, 
proximally to the fifth metacarpal bone, by a large 
hook-like process for the attachment of the deep 
annular ligament, and the origin of the muscles of 
the little finger. The surface elsewhere is narrowed. 
The dorsal surface is free. The radial surface is large, 
faceted nearly the entire surface for articulation with 
the os magnum; it becomes roughened in front for 
ligamentous attachment. The ulnar surface is com- 
pressed as a thin edge lying between the facet for the 
cuneiform and that for the fifth metacarpal bone. 
Variations in the carpal and metacarpal bones are 
of four kinds: (1) Duplication of one of the bones; 
for example, the presence of two semilunar, or two 
scaphoid bones in the place of one. (2) The existence 
of the styloid process of the third metacarpal as a 
distinct bone. (3) The occurrence of an intermediate 
bone (os intermedium') between the scaphoid and the 
os magnum. This is homologous with a larger bone 
in the same locality, which is normal in the carpus of 
some of the quadrumana. (4) A sesamoid bone at the 
insertion of the Extensor Carpi Ulnaris. 
All of the above variations are rare. They have 
been particularly investigated by Gruber.1 
THE METACARPUS. 
The metacarpus (Plate XXX.) is a series of cylindri- 
cal bones placed between the carpus and the first row 
of phalanges. Each bone consists of a shaft, a proxi- 
mal (carpal), and a distal extremity. The shaft, which 
approximates a prism in form (an appearance best 
seen in the second, the third, and the fourth bones) is 
slightly concave beneath. The proximal end is flat 
or concave, and presents in the case of the second, 
the third, and the fourth bones lateral facets for 
articulation with the adjoining carpal bones. The 
distal extremity is rounded, convex, and, with the 
exception of the first, longer than wide. 
1 Arch. Anat. Physiol, und Wissensch. Med., 1862-76; Bulletin 
de l'Acad. Imp. St. Petersbourg, 1870-73. 182 
THE BONES. 
In general outline the first metacarpal bone re^ 
sembles a phalanx. It is shorter and wider than 
the others, and is placed at a greater angle to the 
carpus. It is flat on the dorsal surface, and slightly 
concave, with a tendency to the formation of a ridge, 
on the palmar surface near its carpal extremity. The 
proximal surface is saddle-shaped. The distal surface 
is produced a little toward the palmar aspect. The 
articular surface is broader than it is long, and pre- 
sents on the sides two small facets for the sesamoid 
bones of the Flexor Brevis Pollicis muscle. 
The second metacarpal bone is ridged above at the 
proximal half of the dorsum for the Dorsal Interosse- 
ous muscles. The proximal surface is deeply concave 
for articulation with the trapezoid bone; and is irregu- 
larly faceted for articulation with the trapezium, while 
the ulnar side articulates with the third metacarpal 
bone, and at the same time is produced upward and 
inward to articulate by a small surface with the os 
magnum. 
The third metacarpal bone is a little smaller than 
the preceding. The proximal surface is triangular, 
with the apex of the figure truncated and directed 
toward the palmar surface. It is somewhat oblique, 
and articulates with the os magnum. At the dorsal 
surface on the radial border a small process projects 
upward. The radial border presents a single facet for 
the second metacarpal bone, and the ulnar has two 
facets for the fourth metacarpal. 
The fourth metacarpal bone is yet smaller than the 
third. Its proximal extremity presents two facets; 
one of these, the larger, articulates with the cunei- 
form bone, while the other is reserved for the os 
magnum. The radial border yields two facets for 
articulation with the' third metacarpal, while the facet 
on the ulnar border is single for articulation with the 
fifth metacarpal bone. The axis of the proximal 
extremity may be deflected a little to the ulnar side 
of the axis of the shaft. 
The fifth metacarpal bone is more cylindrical than 
the others of the series. The dorsal surface is marked 
by a faint oblique ridge, to which are attached, at its 
radial side, the fourth Dorsal Interosseous muscle, and, 
at its ulnar side, the tendon of the Extensor Carpi 
Ulnaris muscle. The proximal extremity presents a 
wide, saddle-shaped surface for articulation with the 
unciform bone. A single facet is seen at the lateral 
side of the end of the bone, while the ulnar side is free. 
Synoptical Table of the Metacarpal Bones. 
Proximal end with single facet, having a smooth, rounded dorsal border ..... First and fifth. 
Shallow groove running transversely, no facet on either side ...... First. 
" " " " vertically, facet on median side ...... Fifth. 
Proximal end with multiple facets, and uneven dorsal border ....... Second, third, and fourth. 
Palmar border acuminate. Three proximal and two median facets, dorsal border with central notch . Second. 
" " truncate ........... Third and fourth. 
One proximal with two median and two lateral facets ; dorsal border without notch, but having 
a large lateral process . . . . . . . . . . Third. 
One proximal, two lateral, and one median facet; dorsal border with neither notch nor process Fourth. 
PHALANGES. 
The phalanges (Plate XXX.) constitute the bony 
framework of the fingers. They are fourteen in num- 
ber: three to each of the fingers and two to the thumb. 
The general form of a phalanx is that of a semi-cylin- 
der, the convexity of which is dorsal and the con- 
cavity palmar. The proximal end is somewhat larger 
than the distal. The borders are compressed, and 
marked on the palmar edges by ridges for the inser- 
tion of the tendons of the flexors of the fingers. The 
phalanges of the first row have their distal surfaces 
compressed from the dorsal to the palmar aspect, 
and form a series of narrow, rounded facets (most 
apparent on the palmar side) for articulation with the 
second row of bones. The median and lateral borders 
are each marked with a circular depression, to give 
attachment to the lateral ligaments. The proximal 
facet is circular and concave for the reception of the 
head of the corresponding metacarpal bone, and is 
marked by two tubercles, the inner of which is com- 
monly the larger.-The phalanges of the second row 
present, proximally, two small concave facets, sepa- 
rated by a crest ranging from the palmar to the dorsal 
surface, for articulation with the distal surface of the 
first phalanx. Upon the sides are two tubercles for the 
insertion of the lateral ligaments. The first phalanx 
of the thumb, answering to the second of the other fin- 
gers, is distinguished by a body which is without ten- 
dinous impressions, and by borders which are smooth 
and simple; of these the ulnar border is more concave 
than the radial. The distal surface is not marked by a 
crest, and the tubercle on the radial side of the articular 
surface is more pronounced than that on the ulnar. 
The phalanges of the third row (ungual phalanges) 
diminish abruptly from the proximal surface forward. THE INFERIOR EXTREMITY. 
183 
The palmar surfaces are flat, and marked in advance 
of the distal end by wide expansions for the insertion 
of the tendons of the Flexor Profundus Digitorum. 
The crest on the proximal surface is less pronounced 
than on the phalanges of the second row. The free 
extremity is rounded and elevated, much roughened, 
and is marked on the palmar surface by a triangular 
notch. It serves to support the pulp of the finger tip. 
The sides of the palmar rugosity may be extended 
backward as little spines. The terminal phalanx of 
the thumb is relatively larger than the others. It 
is markedly asymmetrical, the median border being 
shorter and more concave than the lateral. 
The Sesamoid Bones.-The sesamoid bones are 
rounded and seed-like in appearance, and are placed 
in the tendons of the various muscles of the hand at 
the side of the metacarpo-phalangeal joints. They 
are best developed at the thumb, where they are 
lodged in the tendons of the Flexor Brevis Pollicis, 
the Adductor Pollicis, and the Abductor Pollicis 
muscles. Similar structures are also found in the 
tendons of the muscle of the index and little fingers. 
For remarks concerning the sesamoid bones see the 
general considerations of the muscles. 
Development.-Each metacarpal bone and phalanx 
arises from two centres of ossification-one for the 
shaft or main portion, and one for an epiphysis. In 
all the metacarpal bones, excepting the first, the epi- 
physeal centre lies to the distal end of the shaft, but in 
the first it lies to the proximal end. In the phalanges 
the epiphyses are without exception proximately dis- 
posed. The nuclei of the shafts first appear in the 
eighth or ninth week; those of the epiphyses from 
the third to the fifth year. Development is complete 
at about the twentieth year. 
of the framework of the trunk, it is included among 
the bones of the lower extremity. The two innomi- 
nate bones articulate with the sacrum and the coccyx, 
and with them make up the pelvis. 
The innominate bone is subdivided into three 
distinct portions, viz., the ilium, the pubis, and the 
ischium,-which are so disposed as to form two ex- 
panded, irregular plates, arranged end to end and 
connected by a narrow isthmus. The upper plate, 
which may also receive the name of the iliac plate, 
is flattened from within outward; while the lower 
plate, which may also receive the name of the ischio- 
pubic plate, is flattened from before backward. In- 
termediate in position to the above plates is the 
acetabulum. 
Before describing the bone as a whole, the following 
brief account of the three component parts will be 
given. 
The ilium constitutes the upper plate. In a strict 
morphological sense, it also includes part of the ace- 
tabulum, but for practical purposes it is sufficient to 
limit it inferiorly at the isthmus. The pubis forms 
the anterior portion of the ischio-pubic plate, and 
presents a compressed V-shaped figure,-the re-enter- 
ing angle of which forms the body, the upper branch 
the horizontal ramus, and the lower branch the 
descending ramus of the pubis. The ischium com- 
prises the posterior part of the ischio-pubic plate. 
It is more massive than either of the others, and 
presents in common with the pubis a V-shaped figure 
whose posterior prismoidal limb forms the body, and 
the anterior flattened part the ascending ramus. 
A description of the innominate bone includes a 
lateral and a median surface; four borders; and the 
obturator foramen. 
The lateral surf'ace (outer, femoral, external) is more 
irregular than the median, and is divided into (a) the 
dorsum of the ilium, (If the region of the acetabulum, 
and (c) the lateral surface of the ischio-pubic portion. 
(a) The dorsum of the ilium.-The dorsum of the 
ilium is a broad, undulating surface that is covered 
in the undissected subject with the Gluteal and the 
Tensor Vaginae Femoris muscles. It is concave at the 
anterior border, convex on a line with the posterior lip 
of the acetabulum, again concave for the greater part of 
the remaining surface, but is convex near the posterior 
border. Each of these sinuositiesanswers to some points 
of anatomical limitation. Thus, the first concavity 
answers to the origin of the Tensor Vaginae Femoris, 
and in part to the surface of origin of the Gluteus 
Minimus. The first convexity answers to the begin- 
THE BONES OF THE INFERIOR EXTREMITY. 
The bones composing the inferior extremity are 
the innominate bone, the femur, the tibia, the fibula, 
the tarsus, the metatarsus, the phalanges, and the sesa- 
moid bones-including the patella. 
THE INNOMINATE BONE. 
The innominate (pelvic, hip, haunch bone) (Plates 
XXXI., XXXII.) is the largest of the flat bones. It 
articulates with the sacrum and with the correspond- 
ing bone of the opposite side. While forming part 184 
THE BONES. 
ning of the surface of origin of the Gluteus Medius; 
the large second concavity is entirely occupied by 
the same muscle; the small second convexity is much 
roughened for the origin of the iliac fibres of the 
Gluteus Maximus muscle.-The dorsum is crossed by 
three faint lines, the superior, the middle, and the in- 
ferior, curved lines. The superior curved line, is in 
common with the superior iliac border the greater 
part of its length, but is distinct in a nearly vertical 
position on the dorsum at the posterior convexity, 
where it separates the Gluteus Maximus from the 
Gluteus Medius muscles. The middle curved line is 
well marked anteriorly at the first dorsal convexity, 
and arching backward ends at the great sciatic notch. 
It is composed of the lower ends of the oblique 
rugosities for the origin of the Gluteus Medius mus- 
cle. The inferior semicircular line begins at the 
notch above the anterior inferior spinous process, 
and arches backward nearly concentric to the upper 
border of the acetabulum; it answers to the lower 
border of the Gluteus Medius muscle. Along the 
posterior border of the iliac portion are seen two 
processes, the posterior superior spinous process, and 
the posterior inferior spinous process ; these are sepa- 
rated by a faint emargination. 
(6) The region of the acetabulum.-The acetabulum 
(cotyloid cavity, socket for the head of the femur) 
lies below the narrowed portion of the hip bone (isth- 
mus), and is directed downward, forward, and out- 
ward. It is formed by the junction of the main 
divisions of the bone in such a manner that two-fifths 
of its area is derived from the ischium, less than two- 
fifths from the ilium, and nearly one-fifth from the 
pubis. Nearly circular in shape the acetabulum is 
for the most part occupied by a C-shaped articular 
surface. The space between the ends of the curve 
of this figure is depressed, and directed downward 
and forward to form the basal and, at the lower and 
the inner lip, the shallowest part of the socket. 
The articular surface is broadest and deepest on the 
ilium posteriorly where it forms in connection with 
the ischiatic portion the great posterior lip; narrowest 
on the ilium anteriorly where together with the pubic 
portion it forms the anterior lip. In the last named 
locality the curve is nearly continuous with the bot- 
tom of the socket, but on the ischium the curve 
corresponds to a rather bold elevation that forms in 
connection with the bottom the cotyloid notch (inci- 
sura). The articular surface in the unprepared bone 
is covered with cartilage, while the depression is 
filled with fat.-A short distance above the acetabu- 
lum a small transverse ridge is seen for the origin 
of the tendon of the Rectus Femoris muscle. 
(c) The lateral surface of the ischio-pubic portion.- 
The lateral surface of the body of the ischium below 
the acetabulum exhibits a wide yroove for the Obtu- 
rator Externus muscle. On a level with this groove 
on the posterior margin lies the spine of the ischium, 
for the attachment of the lesser sacro-sciatic ligament 
and origin of the Superior and the Inferior Gemelli 
muscles. The ischium ends inferiorly in the tuberosity, 
which presents a broad flat surface looking outward 
and backward, and yields surfaces of origin for the 
Biceps, the Semi-Tendinosus, and the Semi-Membra- 
nosus muscles. The deep excavation on the posterior 
margin of the innominate bone between the posterior 
inferior process of the ilium and the spine of the 
ischium defines the great sciatic notch, which trans- 
mits the Pyriformis and the Obturator Internus mus- 
cles, the sciatic nerves, the gluteal artery and nerves, 
and the internal pudic vessels and nerves. The space 
between the spine of the ischium and the tuberosity 
has received the name of the lesser sciatic notch. The 
ascending ramus of the ischium narrows slightly to join 
the descending ramus of the pubis; an irregular line 
of nodules usually exists here to denote the line of 
sutural union. The lower margin of the ascending 
ramus is broad, continuous with the tuberosity, and 
affords a line of origin for the Adductor Magnus 
muscle. The lateral surface answering to the pubis 
is smooth on the body and on the greater portion of 
the descending ramus, except at the lower margin 
and near the symphyseal line, from which the Ad- 
ductor Longus, the Adductor Brevis, and the Gracilis 
muscles arise. The massive horizontal ramus of the 
pubis broadens posteriorly towards the acetabulum, 
and merges into the anterior border of the innom- 
inate bone. It is grooved obliquely where it enters 
into the upper margin of the obturator foramen for 
the obturator vessels and nerves. 
EXPLANATION OF PLATE XXXI 
Fig. 1. The innominate bone seen from the lateral aspect. 
Fig. 2. The innominate bone seen from the median aspect. 
| For " Linea ileo-pectinea" read " Linea ilio-pectinsea." PLATE XXXI 
Fi£.2 
Fi^.l 
T. Sinclair & Son.Lith. THE INFERIOR EXTREMITY. 
185 
The median surface (pelvic surface) is for the most 
part divided into the iliac and ischio-pubic portions by 
a line,-the ilio-pectineal line,-(linea ilio-pectinma), 
which extends obliquely downward and forward, from 
the anterior border of the surface for articulation 
with the sacrum to near the pubis. 
The iliac portion is comprised of (u) the iliac fossa, 
(i) the facet far articulation with the sacrum, and (c) 
the iliac tuberosity. 
(«) The iliac fossa is smooth and shallow, and occu- 
pies the anterior two-thirds of the ilium. It accom- 
modates the Iliacus Internus muscle, and is limited 
behind by the upper half of the facet of articulation 
with the sacrum and the anterior edge of the iliac 
tuberosity, below by the ilio-pectinal line, and in front 
by the ilio-pubic junction, where a convexity- 
answering to the line of union between the ilium and 
the pubis-is seen, constituting the eminentia ilio- 
pectinsea, over which glides the Iliacus Internus muscle. 
(6) The facet for articulation with the sacrum (auricu- 
lar facet) articulates with the lateral surface of the 
sacrum to effect the sacro-iliac junction. Its inferior 
posterior border forms the projection known as the 
posterior inferior spinous process of the ilium, (c) The 
iliac tuberosity is the rough convexity behind the 
last-named portion, and, when the bone is in articu- 
lation, constitutes part of the dorsal aspect of the 
trunk. It gives attachment to the sacro-iliac liga- 
ment, and in part origin to the Erector Spinse muscle. 
The ischio-pubic portion of the median surface is 
smooth, for the attachment of the Obturator Internus 
muscle. Under the name of the ischial planes, ob 
stetricians indicate the space between the obturator 
foramen and the great sciatic notch. An imaginary 
line, extending from the ilio-pectineal eminence to 
the spine of the ischium, separates the anterior from 
the posterior ischial plane. At the lower margin of 
the ischio-pubic portion are located, in order from 
before backward, the surfaces of origin of the Coc- 
cygeus and of the Levator Ani muscles (a small por- 
tion of the origin of the muscle also lying in front of 
the obturator foramen), the Erector Penis, and the 
Compressor Urethrae muscles; it further affords 
attachment to the crus penis, and posteriorly to the 
great sacro-sciatic ligament. The surface answering 
to the body of the pubis assists in supporting the 
bladder. Along the median surface below the ob- 
turator foramen lie the internal pudic vessels and 
nerves. 
The superior border or the crest of the ilium follows 
the convexities and concavities of the dorsum. It is 
thickest posteriorly where it corresponds to the iliac 
tuberosity, and thinnest directly in advance of the 
part last named. Corresponding to the position of the 
first dorsal convexity, the upper border is abruptly 
widened, and forms a prominence which is of much 
clinical significance, since it lies directly in a line with 
the great femoral trochanter, and serves as a con- 
venient point from which distances can be measured, 
either to points about the hip, or to any part of 
the lower extremity. The superior border presents 
an outer lip, an inner lip, and an intermediate space. 
The outer lip gives origin to the Sartorius, the Tensor 
Vaginae Femoris, the External Oblique muscle of 
the abdomen, the Latissimus Dorsi, the fascia lata, and 
the beginning of Poupart's ligament. The inner lip 
is designed for the origin of the Transversalis, the 
Quadratus Lumborum, and, in part, the Erector 
Spinse muscle. The intermediate space is devoted to 
the origin in part of the Internal Oblique muscle. 
The inferior border corresponds to the lower free 
edge of the descending ramus of the pubis and the 
lower and the lateral borders of the ischium. From 
the tuberosity forward to the angle of the pubis the 
inferior border comprises an outer and an inner lip, 
which have already been described under the head 
of the lower margins of the lateral and the median 
surfaces. The anterior third of the lower border is 
broad and oval, and constitutes the articular surface 
that forms in connection with the corresponding facet 
of the opposite bone the symphysis gmlis. 
The anterior border presents the following points in 
order from above downward. First, the anterior 
superior spinous process, from which and the lateral 
border of the crest the Sartorius muscle arises. 
Second, an emargination. Third, the anterior inferior 
spinous process, for the origin of the long head of the 
Rectus Femoris muscle, and attachment of the ilio- 
femoral fascicle of the capsular ligament. Fourth, 
the thin compressed anterior acetabular lip. Fifth, 
the broad triangular surface whose apex is directed 
forward and inward to form, at the junction of the 
anterior with the inferior borders, the angle. Sixth, 
the pubic spine, which is placed at the upper and 
anterior part of the body of the pubis, and is designed 
for the attachment of Poupart's ligament and the 
conjoined tendon. The interval between the spine 
and the angle gives origin to the External Oblique 
and the Pyramidalis muscles. Seventh, a surface for 
the origin of the Pectineus muscle. 
The posterior border lies between the superior and 
The borders of the innominate bone are the superior, 
the inferior, the anterior, and the posterior. 186 
THE BONES 
the inferior borders. It is thin and compressed in 
the iliac and acetabular portions, but is robust below. 
The posterior border embraces the posterior superior, 
and the posterior inferior spinous processes, the 
greater and the lesser sciatic notches, the ischiatic 
spine, and the ischiatic tuberosity. These have been 
described in connection with the lateral surface. 
The obturator foramen is a large oval or triangular 
opening with sub-rounded angles, and is defined by 
borders derived from the pubis and the ischium. It 
is marked above by a faint prominence near the 
cotyloid notch, and below by another near the pubo- 
ischiatic junction. The foramen in life is occupied 
by a firm fibrous membrane which is covered later- 
ally by the Obturator Externus muscle, and medianly 
by the Obturator Internus. It is pierced above by 
the obturator vessels and nerve. 
Structure. - The greatest amount of compact 
tissue of the innominate bone is found in the curve of 
great sciatic notch and the bone extending thence be- 
neath the spine of the ischium. The compact tissue 
is also well developed at the articular surface of the 
acetabulum and the dorsum of the ilium. The main 
bulk of the bone, however, is spongy, even the iliac and 
the ischiatic tuberosities being in great part composed 
of cancelli. The laminae about the acetabulum are 
coarser than elsewhere, and exhibit radiating fibres 
which pass from the socket laterally, and which are 
intersected by others answering to the curvatures 
of this portion of the bone. The centre of the iliac 
fossa, which is the thinnest portion of the ilium, is, 
as a rule, translucent. In the negro the bone is 
massive, and the translucent appearance above men- 
tioned is absent. 
Development.-The innominate bone arises from 
eight centres of ossification. The first centre appears 
in the ilium at about, the eighth week; the second, in 
the ischium at the third month ; the third, in the pubis 
at the fifth month. The remaining centres are acces- 
sory to the above. The ilium exhibits two secondary 
points of ossification, the one for the crest, the other for 
the anterior inferior spinous process. The ischium 
retains one centre for the tuberosity; and the pubis 
also one for the symphyseal surface. The pubis and the 
ischium unite by their adjoined rami at about the 
eighth year. After the three main portions of the in- 
nominate bone have contributed to define the acetabu- 
lum, there still remains intermediate to their opposed 
surfaces at the bottom of the socket, a Y-shaped piece 
of cartilage, within which at about the eighth year, 
a nucleus of bone, retaining the shape of the cartilage, 
appears; this nucleus, while not serving as an epi- 
physis to any of the innominate segments, unites 
therewith about the twentieth year. 
Remarks.-The innominate bone presents many 
varieties in the proportions and in the degrees of mas- 
siveness of the several parts composing it, while yield- 
ing but few distinct variations of minor character. 
Malgaigne invites attention to the fact that the pro- 
jection of the first convexity of the dorsum of the 
ilium forms a dividing line of surgical significance. 
In fracture near the crest he finds the lines extending 
either from the portion in front of the convexity 
backward or from a point back of the convexity 
forward.-Osteophytes have been noted arising from 
the ilio-pectineal line to a sufficient height to serve 
as an exciting cause of uterine laceration during 
labor.1-The posterior lip is liable to be broken in 
dislocation of the head of the femur backward. Mr. 
H. Morris2 believes that such fracture always occurs. 
This extreme position is controverted by Mr. F. S. 
Eve,3 who, while accepting the fact that the lesion 
may occur, mentions three instances in which the 
acetabulum remained intact. It must be borne in 
mind that the dislocation is assumed to take place 
by such violence as to thrust the femur upward and 
backward. 
In the living subject the crest of the ilium, and the 
lateral aspects of the ischium and the pubis can be in 
a measure discerned beneath the integument. In 
vaginal examinations with the finger the median sur- 
faces of the pubis and the ischium can be outlined, 
while the spine of the ischium can be recognized with 
distinctness.-The highest point of the ilium is about 
on the level of the spine of the fourth lumbar verte- 
bra.-The anterior superior spinous process is a little 
below the level of the promontory of the sacrum. 
THE PELVIS. 
The pelvis (Fig. 1, Plate XXXII.) is the figure re- 
sulting from the union of the innominate bones with 
the sacrum and the coccyx. The artificial pelvis 
closely resembles the ligamentous, the most important 
distinction lying in the inferio-lateral portion, where 
the great sciatic ligament modifies the shape of the 
outlet of the osseous pelvis. 
1 New York Medical Journal, xi. 424. 
2 Med.-Chir. Trans., lx. 161. 
3 Med.-Chir. Trans., Ixii. 51. THE PELVIS 
187 
The pelvis receives its name from its rude resem- 
blance to a basin. The brim of the basin must be 
considered as broken in front and behind; the latter 
opening, however, is in part occupied by the last 
lumbar vertebra. 
The pelvis is divided by the ilio-pectineal line, and 
by the portions answering to the production of this line 
backward upon the sacrum, and forward upon the pubis, 
into the true and the false pelvis. The false pelvis 
(great pelvis) is in connection with the wall of the 
abdomen, which it aids to support; it is concave for 
the accommodation in part of the intestinal coil, and 
for the ovaries and the beginning of the Fallopian tubes 
in the female. The true pelvis (lesser pelvis) accom- 
modates the internal organs of generation, the rectum, 
and in part the bladder. It is closed inferiorly by 
the perineum. The superior outlet of the true pel- 
vis is called the brim, or the superior strait. Its 
figure is cardiform, the base answering to the pro- 
montory of the sacrum, the sides and the apex to the 
ilio-pectineal line. The inferior outlet is called the 
inferior strait or outlet. It is of an irregular out- 
line. In front it answers to the triangular space de- 
fined by the conjunction of the ascending limb of the 
ischium and the descending limb of the pubis on each 
side of the symphysis pubis; at the sides it answers 
to the double sinuate line, extending from the tuber- 
osity of the ischium to the sacrum. As already men- 
tioned, the great sacro-sciatic ligament defines the in- 
ferior strait laterally in the ligamentous pelvis. The 
walls of the true pelvis are straight and smooth at 
the sides and at the back, and concave at the back 
and the front. 
carefully define its diameters. These will be pre- 
sented in the following order :-• 
The conjugate diameter (antero-posterior, sagittal) 
of Niigele is a line drawn from the promontory of the 
sacrum to the superior margin of the symphysis 
pubis. It measures at the 
Superior strait . . . . 4| inches. 
Cavity " 
Inferior strait . . . .5 " 
The transverse diameter is a line drawn between 
the acetabula, as follows:- 
Superior strait . . . . inches. 
Cavity ..... 4f-5 " 
Inferior strait .... 4-41 " 
The following are the oblique diameters:-■ 
Superior strait . . . .5 inches. 
Cavity . ' . . . . " 
Inferior straight . . . 4f " 
The pelvis not being exactly symmetrical, the right 
oblique diameter is somewhat shorter than the left. 
Hermann Meyer describes a diameter named by 
him the normal conjugate. This line passes from 
the middle of the anterior surface of the third sacral 
vertebra to the upper border of the symphysis 
pubis. It is accepted as a more constant measure- 
ment than the conjugate, since it is not subject to 
material variation from the position of the pelvis or 
from the vertebral column. Meyer recommends in 
order to make satisfactory measurements of the pel- 
vis that the observer place the anterior superior spin- 
ous process of the ilium and the spine of the pubis 
on the same vertical line, the body to be erect, as in 
the act of standing, and the limbs to be neither ab- 
ducted nor adducted. 
The most important of the external measurements 
of the pelvis are the following:-■ 
Between the anterior superior spinous processes, 
10 inches; between the central points of the crests 
of the ilia, 10 inches; between the spinous process of 
the last lumbar vertebra and the upper border of the 
symphysis pubis (external conjugate), 7 inches. 
The pelvis presents some striking sex distinctions. 
Thus the bones of the female pelvis (Fig. 72) are 
lighter in structure than are those of the male; the 
true pelvis is wide and short, and possesses a cylin- 
drical figure, which, in the child-bearing woman, is so 
modified as to be slightly increased in its transverse 
over its antero-posterior diameter. In the male (fig. 
1, Plate XXXII.), the true pelvis is narrow and high, 
and the figure is somewhat ovate from before back- 
Fig. 71. 
The pelvis seen from above, showing the position of the sagittal, frontal, and 
oblique diameters. 
The Diameters of the Pelvis. (Fig. 71.)-The im- 
portance of a knowledge of the pelvis in connection 
with the science of obstetrics has led observers to 188 
THE BONES. 
ward. In the female the sub-pubic arch is wide and 
rounded at the symphysis, and formsan angle of about 
90° to 100° ; in the male the arch is angulated, and 
forms an angle of from 70° to 75°; in this sex the 
obturator foramen is also of a triangular figure. 
The axis of the pelvis is the sum of the lines unit- 
ing the centres of geometrical planes defined within 
the cavity of the true pelvis. This has been described 
as an irregular parabola. Considered as representing 
the line of descent of the body of the child during 
delivery the pelvic axis, as above defined, is approxi- 
mately true only, since the pelvis, considered as a 
ligamentous or an artificial structure, retains, to an 
imperfect degree, the diameters of the inferior strait. 
Mechanism of the Pelvis.-The pelvis is sustained 
in its relation to the trunk by the sacro-lumbar arti- 
culation, and with the lower extremity by the hip- 
joint. It is inclined slightly downward and for- 
ward, so that the plane of the superior strait assumes 
to a horizontal plane an angle of 55° to 65°. The 
exact degree of angulation present is determined by 
the amount of flexure in the lumbar vertebrae. The 
bones of the pelvis are not immovably fixed, but per- 
mit a moderate amount of motion to occur normally 
between one another. 
The female pelvis. 
Race distinctions can also be determined as well as 
those of sex. In the negro the transverse diameter 
o 
Fig. 74. 
Diagram showing the inclination and axis of the true pelvis. 
is less than in the white. The race distinctions of 
the pelvis have been made the subject of elaborate 
study by Mr. J. G. Garson.1 
Section of pelvis showing the suspensory action of the sacro-iliac ligaments. 
While sustaining the weight of the body, the sacrum, 
being broader behind than in front, would slip for- 
ward, if the motion were not checked by the stout 
ligaments uniting it with the innominate bone. The 
1 Journal of Anatomy and Physiol., vol. xvi., Part I., 1881, 
106 (figs.). 
EXPLANATION OF PLATE XXXII. 
Fig. 1. The male pelvis seen from in front-the coccyx is I 
absent. 
Fig. 2. The innominate bone seen from in front, PLATE XXXll 
Fi^ I 
Fig 2 
T. Sinclair 1 Son.litK, THE FEMUR. 
189 
posterior of these ligaments, while thus checking the 
movement downward, will cause a slight degree of 
motion to take place at the symphysis. The latter, 
therefore, bears a direct relation to the amount of 
pressure forward of the sacrum against and between 
the innominate bones.-The lower part of the sacrum 
is so firmly fixed to the hip-bones by the sacro-sciatic 
ligaments (i. e., on a plane below that of the symphysis 
pubis) as not to permit of motion. The pelvis when 
deformed, as in rickets, exhibits the greatest degree 
of deformity at and above the symphysis,-a result, 
it is thought, of the difference of effect of sacral pres- 
sure upon the innominate bone at and above the 
pubis, as contrasted with pressure below this bone. 
In standing, the weight of the trunk rests upon the 
inferior extremities at the acetabula, and upon lines 
extending thence to the sacrum. The arch defined 
by connecting these lines has received the name of 
the cotylo-sacral arch. The line extending from the 
acetabula round the anterior surface of the true pelvis 
has received the name of the cotylo-pubic tie. In sit- 
ting, the weight of the body is borne by the tuberosi- 
ties of the ischia, and is thence transmitted by arched 
lines to the sacrum. The sum of these lines has re- 
ceived the name of the ischio-sacral arch, and the line 
extending thence to the pubis the name of the ischio- 
pubic tie.1 
THE FEMUR. 
The femur or thigh-bone (Plate XXXIII.) is at once 
the longest and the largest bone in the body. It articu- 
lates above with the innominate bone and below with 
the tibia and the patella. When the lower extremity 
of the femur is placed with the condyles resting on 
the same plane, as in articulation, the axis of the 
shaft is oblique to a line dropped through the centre 
of the trunk. 
The bone is divided into a shaft and two extremi- 
ties. 
The shaft is massive, compact, moderately curved 
upon itself from above downward, and twisted at its 
upper third. It presents in front and at the sides 
convex surfaces; of these the posterior is roughened 
above and ridged for muscular attachments, but is 
flat below where it enters into the popliteal space. 
Cylindroid or prismatic, with rounded angles at the 
middle third, the shaft is compressed, widened, and 
irregular both at the upper and at the lower thirds. 
-The middle third of the shaft is smooth in front, and 
narrowed behind to form a prominent ridge called the 
tinea aspera, which presents for examination two 
lips and an intermediate space. The lateral (outer) 
lip, the more prominent of the two, receives the inser- 
tion of the central portion of the Vastus Externus; 
the median (inner) lip receives the corresponding part 
of the Vastus Internus; the intermediate space is occu- 
pied by the insertion in part of the Adductor Magnus 
muscle.-The upper third of the shaft, as already 
mentioned, appears to be slightly twisted upon the 
lower two-thirds. It is robust and subcylindrical, 
and presents a smooth anterior surface, somewhat 
flattened, and a rough posterior surface, upon which 
is a ridge continuous with the linea aspera. The 
lateral lip of this ridge is designed for the insertion 
of the Vastus Externus, and is directed nearly verti- 
cally upward to the lateral aspect of the base of the 
lesser trochanter. Still further to the lateral side of 
this line, namely at a point about two inches below 
the upper end of the shaft, is seen a deep narrow de- 
pression for the insertion of the Gluteus Maximus. 
The continuation of the median lip becomes, as it ap- 
pears upon the median surface of the bone, the spiral 
line, which winds upward and inward round the lesser 
trochanter to the front of the shaft, where it ends in 
the tubercle, a rounded prominence situated at the ante- 
rior border of the great trochanter. The lower part 
of the spiral line in front of the lesser trochanter re- 
ceives the insertion of the Pectineus muscle. W. Roger 
Williams1 proposes the name of inferior cervical tubercle 
for a moderate elevation at the middle of the spiral 
line to which the Vastus Internus muscle effects im- 
portant attachments. As distinguished from this the 
same writer calls the tubercle at the top of the spiral 
line the superior cervical tubercle. Above, the spiral 
line gives origin to the Vastus Internus muscle, and 
in front of the femur to the Crurseus. In the space 
defined by the lines above described are inserted the 
Adductor Longusand the Adductor Brevis muscles.- 
The lower third of the shaft is much broader than the 
upper, and is marked laterally and behind by the 
lines of the linea aspera as they pass to the condyles, 
the external of the two lines being the more prominent. 
The median line near its point of separation from the 
linea aspera is interrupted by the femoral artery as it 
winds round the femur to become the popliteal. Upon 
this line above thi enternal condyles is a minute spur- 
like tubercle corresponding in position to the highest 
point of the patellar groove as well as to the junction 
of the shaft with the epiphysis. It is designed for 
the insertion of the long tendon of the Adductor Mag- 
1 John Wood, art. Pelvis, Cyclopedia of Anatomy and Physiology 
(Supplement), 1859. 
1 Journ. Anat, and Phys. 1879. 190 
THE BONES. 
nus muscle. The shaft is nourished by a branch of 
the femoral artery which enters a canal situated about 
the junction of the middle and the upper third of the 
shaft, and is directed upward. 
The upper extremity of the femur presents for ex- 
amination the head, the neck, the great trochanter, 
and the lesser trochanter. 
The head is large and rounded, and enters into the 
construction of the hip joint. It corresponds in posi- 
tion to a vertical line produced upward from the inner 
condyle. Describing nearly two-thirds of a sphere, 
the head presents a larger articular surface above 
than below the transverse plane, and projects over the 
neck more sharply below than above. At the lateral 
margin the head is continuous with the front of the 
neck, and extends thereon a few lines beyond the 
general articular surface. A little below and behind 
the centre of the head is a shallow circular depression 
for the attachment of the ligamentum teres. Else- 
where the head is separated from the neck by a 
shallow groove. With the exception of the depres- 
sion for the ligamentum teres the head of the femur 
is covered with cartilage in the living subject. 
The neck is a broad process of bone directed 
obliquely upward and inward from the upper end of the 
shaft at an angle of about 130°. Compressed from be- 
fore backward, its anterior part is much flatter than the 
posterior, and presents, as a rule, a long narrow oblique 
border below, and a straight rounded more horizontal 
border above, which is perforated with numerous 
venous foramina. The neck is marked in front near 
the articular surface by a faint depression, which is 
often cribriform in appearance, and may receive the 
name of the cervical fossa. The neck is limited below 
by the inter-trochanteric line, and in front by the 
spiral line. A number of small nutritious foramina 
are seen on the hinder aspect of the neck at its base. 
The great trochanter (trochanter major) is a large 
process continuous with the shaft and inclined to its 
lateral side. It lies on a lower level than the head, 
namely about three-quarters of an inch, and when 
the femur is in articulation it is nearly on a level 
with the spine of the pubis. It is irregularly quadri- 
lateral in shape, the posterior border being imperfect. 
The anterior border is limited about the position of 
the tubercle at the point where the Vastus Externus 
and the Gluteus Maximus muscles meet. The superior 
lorder is rounded, and serves behind at its free portion 
for the insertion of the Pyriformis, and in part, where 
it is continuous with the neck, for the insertion of the 
Obturator Internus. At the angle of junction of the 
superior and the anterior borders, the Gluteus Mini- 
mus is inserted, while the corresponding angle between 
the superior and the posterior borders forms a promi- 
nent process, which lies about on a level with the 
depression for the ligamentum teres. The inferior 
lorder is obscure, and answers to the line of union of 
the trochanteric epiphysis with the shaft. The ante- 
rior surface of the great trochanter is flat. The 
posterior surface is large and convex, and is crossed 
obliquely from above downward and forward and from 
within outward by a faint r/cZye'which limits inferiorly 
the space for the insertion of the Gluteus Medius 
muscle. Below this ridge is a smooth surface (covered 
by a bursa in the subject) over which glides the 
Gluteus Maximus. The median surface is depressed 
to form the digital fossa, into which is inserted the 
tendon of the Obturator Externus, and, in part, that 
of the Obturator Internus. 
The lesser trochanter (trochanter minor) is designed 
to receive the insertion of the conjoined tendon of the 
Iliacus Internus and the Psoas Magnus muscles. It 
is situated below and behind the base of the neck, and 
is directed inward and backward. It is somewhat 
nipple-shaped, and presents a posterior surface which 
is smooth, and on the plane of the general posterior 
aspect of the bone at this point. The anterior, supe- 
rior, and inferior surfaces are free; the last serve to 
support the process from below. The summit of the 
lesser trochanter is, in the living subject, covered by 
a bursa over which glides the Quadratus Femoris 
muscle. 
Under the name of the intertrochanteric line is in- 
cluded a prominent ridge extending obliquely down- 
EXPLANATION OF PLATE XXXIII. 
Fig. 1. The femur seen from behind in natural position. 
Fig. 2. The femur seen from in front in conventional posi 
tion. 
Fig. 3. The femur seen from the lateral aspect in the natu- 
ral position. 
The words " Depression for annular ligament" should be 
omitted. PLATE XXXIII 
Fig. 1 
Fig. 3 
Fig.2. THE FEMUR. 
191 
ward and inward, and joining the inferior border of 
the great trochanter with the lesser trochanter. It 
limits the base of the neck. At a right angle to the 
above-mentioned line the Quadratus Femoris muscle 
is inserted. 
The lower extremity of the femur is broad, and trans- 
versely flattened, and is wider behind than in front. 
It presents for examination an external (lateral) and 
an inner (median) condyle, together with the inter- 
condyloid notch and the patellar groove.-The exter- 
nal condyle yields a lateral, nearly flat border, which 
is continuous with the lateral surface of the shaft. 
The articular surface is convex and broad^ but nar- 
rowed slightly as it approaches the posterior surface, 
where it terminates in a horizontal border. Above 
it lies a faint impression for the origin of the lateral 
(outer) head of the Gastrocnemius muscle. The 
lateral surface presents a rounded eminence called the 
external tuberosity. Below this the surface is marked 
by a pronounced depression for the external lateral 
ligament, and the groove for the Popliteus muscle.- 
The internal condyle is inclined obliquely inward and 
slightly downward, and broadens at its posterior 
oblique border. Above is a depression for the origin 
of the median (inner) head of the Gastrocnemius 
muscle and the internal tuberosity (corresponding in 
position with the eminence on the external condyle) 
for the attachment of the internal lateral ligament. 
When the isolated bone is placed in a vertical posi- 
tion, the inner condyle descends below the level of 
the outer; this effect disappears when the bone is 
placed as in articulation. 
Posteriorly the condyles are separated by a deep 
notch - the intercondyloid notch-whose opposed 
lateral surfaces and base are concave for the attach- 
ment of the crucial ligaments.-The condyles are con- 
tinuous anteriorly by means of a shallow, saddle- 
shaped surface, termed the patellar groove, whose 
deepest convexity lies on a level with the top of the 
inter-condyloid notch posteriorly, and whose greatest 
convexity lies to the outer side of this depression. 
The notch answers to the resting-place of the patella 
in the position of the thigh in extension. Above the 
patellar notch is a long, shallow excavation, covered 
in the fresh state with thick periosteum, and furnished 
with orifices for veins. 
Structure.-The walls of the shaft are enormously 
thick, the median being somewhat the heavier. The 
proximal end of the bone exhibits five sets of lines in 
the spongy tissue, which are limited abruptly inferi- 
orly at a little below the level of the trochanter minor, 
and thence extend through the upper portion of the 
bone. The first set are confined to the head, and, in- 
deed, distinguish its epiphysis throughout life. The 
lines are arranged in close series, radiately to the 
curve of the articular surface. The line of junction 
with the neck is at times marked by a number of 
coarser interspaces than those seen elsewhere. The 
second set begin opposite the trochanter minor, and 
pass upward to the epiphyseal junction, which it for 
the most part occupies, as a cluster of straight, stout 
lamellae. In some specimens these lines are so closely 
serried as to present the appearance of compact tissue. 
Toward the proximal end of the lower border they 
are weaker. The third set are coarse, and range from 
opposite the lesser trochanter down to the lower limit 
of the spongy area. They serve to faintly intersect 
the fourth set, which are the strongest and the best 
developed. These range curvilinearly from the lateral 
border of the line at and below the base of the great 
trochanter to the upper portion of the epiphyseal 
junction. Some of the stouter of these lines, as they 
range from the upper border of the neck toward its 
axis, may be continuous with the weak upper border, 
as described by H. C. Bigelow.1 The fifth set are the 
loosely arranged and weak cancelli of the great tro- 
chanter.-The distal end of the bone is occupied by a 
set of stout, nearly vertical lines in the outer condyle, 
which pass thence to the outer side of the shaft, and 
a second much weaker and more oblique set in the 
inner condyle. A number of weak transverse lines 
intersect the foregoing at right angles. 
Development.-The femur arises from five centres 
of ossification. The first appears in the shaft at about 
Fig. 75. 
A longitudinal section of the head and neck of the femur, showing the posi- 
tions of the epiphyses for the head and the great trochanter. 
the fifth to the seventh week. The second appears 
in the condylar epiphysis at the ninth month of foetal 
* The Hip, p. 120. 192 
THE BONES. 
life. The third appears in the head of the bone at 
the end of the first year. To these are added, as 
secondary ossifications, the centre for the great tro- 
chanter at the fourth year, and the centre for the 
lesser trochanter at the thirteenth year. 
The lesser trochanter unites with the shaft at the 
seventeenth year; the great trochanter and the head 
of the femur a year later; the condylar epiphysis 
ossifies with the femur soon after the twentieth year. 
Remarks.-The depression for the ligamentum teres 
varies greatly in size. Generally of a triangular 
form, it is often irregularly rounded, with swollen, 
everted lips; its size is greater, other things being 
equal, in young than in adult bones; and it is more 
acutely depressed in large massive specimens than in 
smaller and thinner ones. In the former, the lower 
lip is often thickened and thrown forward.-In cer- 
tain specimens from females the depression is very 
shallow, and the foramina at the bottom are gene- 
rally present. Sometimes reduced to one - often 
numerous and larger-they are well seen in young 
adult bones; but faintly marked, or entirely absent 
in oldish, or heavy massive ones. In arthritis, the 
depression is either entirely filled up, and even pro- 
duced, or it is scooped out, and bears osteophytes 
upon its borders. The shape of the head varies. 
The proximal end of the line of insertion of the 
Gluteus Maximus is often more pronounced than 
the remaining portion; when exaggerated in size, this 
prominence has received the name of the third tiochan- 
ter, from the fact that it is analogous to a similar 
projection on the femur of some of the lower animals, 
such as the horse and the rhinoceros.-The epiphyseal 
line at the head lies within the embrace of the capsule. 
In some diseases of the femur, as, for example, in- 
flammation at the head of the bone in coxalgia, the 
epiphysis may become detached.-The distal epiphysis 
may be detached by violence, and thereby simulate 
compound fracture of the lower third of the shaft.-An 
exostosis of the femur occasionally occurs by ossifi- 
cation of the tendinous insertion of the Adductor 
Magnus.-An exostosis from the posterior surface of 
the femur at its lower end has been known to rupture 
the popliteal artery and necessitate amputation of the 
thigh.1-An exostosis upon the inner side of the 
femur at the middle third is supposed to be caused 
by the frequent pressure of the thigh against the 
side of the horse in riding, and has from this cir- 
cumstance received the name of dragoon's exostosis. 
Necrosis of the femur is more frequent at the lower 
third of the shaft than elsewhere, particularly in the 
adolescent. This frequency is probably connected 
with the great vascularity of this portion of the bone 
during development. 
THE TIBIA. 
The tibia (figs. 1, 2, 3, Plate XXXIV.) is the largest 
of the long bones, the femur alone excepted. The 
shaft is for the most part prismoidal in form, narrower 
at the lower third than elsewhere, and presents a 
well-marked irregular expansion above to constitute 
the upper, and a smaller but decided increase of 
width below to constitute the lower extremity. The 
limits of the extremities are not, however, accu- 
rately distinguished from those of the shaft. 
The tibia articulates by its lateral surfaces with the 
fibula at both the upper and the lower end. Above, 
the tibia is in articulation with the femur, and below, 
with the astragalus. 
The upper extremity is expanded and elongated 
transversely, so that the borders project beyond the 
shaft, the median projection being the larger of the 
two. Above are seen two articular facets, the condy- 
loid (glenoid) surfaces, for the femoral condyles. Each 
of their surfaces is of an oval shape, the internal being 
the more elliptical of the two. Between them is seen 
the spine of the tibia placed nearer the posterior than 
the anterior margin of the bone, and presenting two 
lateral tubercles, each of which is continuous with the 
curve of its own articular surface,-the median inter- 
nal tubercle being the larger. Between the spine and 
the anterior border on the one hand, and the spine 
and the posterior border on the other, are two rough 
triangular surfaces for ligamentous attachment; the 
posterior of these is the more oblique, and is designed 
for the attachment of the posterior crucial ligament; 
the anterior is for the attachment of the anterior crucial 
ligament and the semilunar cartilage. The lateral 
surfaces of the upper extremity of the bone form the 
tuberosities. These are smooth, convex prominences, 
the median being the larger, and marked behind by 
a depression for the middle division of the tendon of 
the Semimembranosus muscle. The lateral tuberosity 
is broader than the median, and is further distin- 
guished by a flat rounded facet directed downward 
and backward for articulation with the facet on the 
head of the fibula. In front a tubercle is situated for 
the origin of the Tibialis Anticus muscle. Posteriorly 
the upper extremity is slightly depressed, and exhibits 
between the articular surfaces the popliteal notch (inter- 
i Boling, N. A. Med. Chir. Rev., 1857, 608. THE TIBIA 
193 
condyloid notch). Anteriorly lies a smooth triangular 
surface whose apex is directed downward, and whose 
base lies a little backward therefrom on a level with 
the articular facets. This space is furnished with nu- 
merous vascular foramina, and in life is covered with 
a thick cushion of tough fatty tissue. At the apex 
the surface is provided with the roughened tubercle 
for the. attachment of the ligamentum patellse. Imme- 
diately above the tubercle the bone is smooth for the 
accommodation of a bursa. 
The shaft of the tibia is broad above, but gradu- 
ally narrows at its lower third, from which point of 
narrowing it slightly increases in size to the lower 
extremity. ' It presents an anterior, a lateral, and a 
posterior surface, and three borders of the same name. 
The anterior surface is smooth, and, for the most 
part, slightly convex. At its upper third it receives 
the aponeurosis made up of the expanded tendons of 
the Sartorius, the Gracilis, and the Semimembranosus 
muscles. The middle third is smooth and subcuta- 
neous, and forms the " shin " of common language. 
The lower third is slightly depressed if not concave; 
it is in part subcutaneous, and in part covered by 
the tendons of the extensors of the toes. 
The lateral surface is concave for the upper two- 
thirds, somewhat convex at the lower third. It is 
furnished throughout its entire length with a ridge for 
the attachment of the interosseous membrane. The 
ridge lies near the posterior border, if, indeed, for the 
lower two-thirds of its length it does not define it, 
and is especially well marked at the lower end of the 
shaft, where it is the frequent site of small, irregular 
outgrowths. In front of this ridge, at its upper part, 
is a broad, shallow depression for the origin of the 
Tibialis Anticus muscle. 
The posterior surface, the least regular of the three, 
is flat above, where it is marked by an oblique line 
which passes from the upper and the outer border 
downward and inward to terminate at the median bor- 
der of the shaft at the junction of the upper and the 
middle thirds. It serves for the origin of the Popli- 
teus muscle. Tne surface above the oblique line is 
covered by the last-named muscle; that below the line, 
as far as the position of the downward-directed nu- 
trient foramen, by the origin of the Soleus muscle. 
Passing thence down the middle third of the bone 
is a vertical ridge (becoming indistinct below) which 
serves to separate the origin of the Flexor Longus 
Digitorum from that of the Tibialis Posticus muscle. 
Of the borders of the tibia, the anterior is prominent 
at its upper two-thirds (crest of the tibia), but rounded 
and inconspicuous at its lower third. It is slightly 
curved outward at its upper third. It separates the 
anterior from the lateral surfaces. The lateral border 
is rounded and faintly expressed below the external 
tuberosity by a rounded surface. At the lower ex- 
tremity it is more compressed, and answers to the 
ridge for the interosseous membrane. It separates the 
lateral from the posterior surface. The posterior bor- 
der is well developed at its lower two-thirds, and is 
continuous above with the oblique line. In the 
upper third the border is smooth and rounded. It 
separates the anterior from the posterior surface. 
The lower extremity is subtriangular in form, pre- 
sents a base directed downward, and is furnished 
with swollen borders before and behind that project 
beyond those of the distal articular surface. The 
anterior border is for the most part smooth, but pro- 
vided near the articular surface with a rounded 
eminence for the attachment of the anterior tibio- 
fibular ligament. The posterior border is slightly 
smaller, and projects a little further downward than 
the foregoing. It is marked by a deep oblique groove 
(overlying the posterior surface of the internal malleo- 
lus) for the tendons of the Tibialis Posticus and the 
Flexor Longus Digitorum muscles. A fainter and less 
constant groove lying to the lateral side of the fore- 
going is designed to accommodate the tendon of the 
Flexor Longus Pollicis muscle. The lateral surface 
of the lower extremity is concave, and presents a small 
facet for articulation with the fibula; the median 
surface projects downward as a robust process, wider 
behind than in front-to form the internal malleolus. 
The under surface of the malleolus is smooth for at- 
tachment of the deltoid ligament. The distal articular 
surface of the tibia is broad, triangular, with its base 
directed laterally, its apex medianly, at which point 
it is abruptly deflected downward to form the lateral 
surface of the internal malleolus. 
Structure.-At the proximal end of the tibia are 
seen two sets of nearly vertical lines passing from the 
condylar surfaces downward to the sides of the shaft. 
In the space between these, weak interlacing oblique 
lines, as well as others that terminate upon the sides of 
the spine above and the median aspects of the condylar 
lines below, are detected. Arranged horizontally to 
both the foregoing are simple, nearly concave lines 
which are sparsely distributed below the articular 
surfaces, and arc in a measure concentric therewith. 
In some specimens the lines of the epiphysis can 
be easily distinguished from those of the shaft. All 
the lines on the median half are stouter than those on 
the lateral. 194 
THE BONES. 
At the distal end substantially the same arrange- 
ment exists as in the radius and ulna. Langerhans 
describes the cancelli as made of a scries of lines ar- 
ranged either vertically to the articular surface or 
slightly converging to it; they are intersected by weak 
transverse lines. The arrangement varies in detail in 
the internal malleolus, as contrasted with the proper 
axial articular surface of the bone. The details of the 
epiphysis are measurably distinct from those of the 
shaft. 
Development.-The tibia arises from three cen- 
tres of ossification. One for the shaft, which appears 
at the fifth or seventh week. One for the upper 
epiphysis at the ninth month of foetal life. One for 
the lower epiphysis at the second year. The last 
joins the shaft at the twentieth year, and the first 
at the twenty-fifth. The tubercle very rarely arises 
from a centre of ossification separate from the proxi- 
mal epiphysis. 
When the shaft of the tibia is much compressed 
from side to side, as occurs in some savage and prim- 
itive races of men, it receives the name of the flat or 
platecnemic tibia.-The upper articular surfaces are 
sometimes placed obliquely to the axis of the shaft 
in such wise as to present the median surface on a 
higher plane than the lateral. This disposition of 
parts is commonly if not always found in limbs in 
which the position of extreme flexion has been main- 
tained for a long time -In chronic rheumatoid 
arthritis the spaces behind and in front of the tibial 
spine are obliterated by new bony growths. 
Remarks.-Separation of the epiphysis of the distal1 
end of the tibia has been observed by R. W. Smith 
and R. Quain in lads sixteen and seventeen years of age. 
In this condition the internal malleolus will preserve 
its natural relations to the foot, but not to the leg or 
outer ankle. M. De Morgan2 records a case of detach- 
ment of the tubercle of the tibia by muscular action 
in a boy of seventeen years. Deep-seated abscess of 
the bone is relatively frequent at about the junction 
of the upper portion of the bone with the shaft.-The 
tibia is liable to extraordinary deformation in rickets, 
owing to the fact that the resistance of the weight of 
the body is to a great degree transferred to it from 
the foot.-Exostoses may arise from the points of 
origin and insertion of muscles at the upper third 
of the bone.-From its peculiarly exposed situation, 
the anterior surface of the middle third of the shaft 
is a frequent seat of the changes incident to chronic 
ostitis and necrosis. 
THE FIBULA. 
The fibula (figs 4, 5, Plate XXXIV.) is a long slen- 
der bone placed to the outer side of the tibia with 
which it is in articulation at its two extremities. 
Below it joins the astragalus at the outer side. Its 
position as compared with that of the tibia is slightly 
oblique from above downward and forward. It is 
slightly twisted inferiorly. The inferior extremity is 
thus placed a little in advance of the upper, at the 
same time that the lower half is directed inward 
toward the tibia. 
The fibula consists of a shaft and an upper and a 
lower extremity. 
The zipper extremity consists of a head, a neck, and 
a styloid process. The head is a rounded prominence 
exhibiting an oblique proximal surface directed down- 
ward and inward, and is distinguished by an oval 
facet (often inconspicuous) for articulation with the 
tibia. Laterally and posteriorly the head is subcuta- 
neous in part. Along its free surface the Soleus and 
Peroneus Longus muscles arise. Behind the superior 
posterior tibio-fibular ligament is attached, and in 
front the superior anterior tibio fibular ligament. 
The neck is a term conventionally applied to that por- 
tion of the shaft immediately below the head. Strictly 
speaking, it has no limitation. The styloid process of 
the fibula is directed proximally along the lateral side 
of the bone, and is designed for the attachment of the 
tendon of the Biceps muscle, and the short external 
lateral ligament of the knee-joint. 
The shaft of the fibula is slender and more robust in 
the middle third than elsewhere. It is prismoidal and 
somewhat triangular in its upper two-thirds; irre- 
gularly lozenge-shaped in its middle third, and ellipti- 
cal in its lower third. The shaft presents for exami- 
nation three borders, three surfaces, and the ridge for 
the interosseous membrane. The anterior lorder ex- 
tends from near the head to the lower third in a sharp, 
straight, well-defined line. As it approaches the 
lower third of the bone, it inclines outward and bifur- 
cates, the inner branch of the bifurcation continuing 
as a straight line to the lower extremity, the outer 
diverging downward and outward to terminate on the 
outer surface of the external malleolus. The external 
lorder is more rounded than the anterior; it passes 
downward along the outer border to the lower third 
of the shaft, where it turns slightly backward to con- 
stitute the posterior border of the lower third. It 
1 British Med. Journ., Aug. 1867, 123. 
2 Med. Times and Gazette, 1853, 268. THE FIBULA 
195 
ends at the corresponding border of the external, 
malleolus. The internal border is of less significance 
than the others. It is obscurely developed near the 
head; but about two inches below this part it assumes 
a linear appearance and continues hence to the lower 
third of the bone where it crosses the inner surface 
obliquely to terminate, as a rule, by joining the ridge 
for the interosseous membrane. This ridge begins 
near the head of the bone close to the inner side of 
the articular border, whence it continues downward 
along the inner surface to be lost above the articular 
surface of the external malleolus.-The external sur- 
face is concave at its upper two-thirds for the origin 
of the Peroneus Longus and the Peroneus Brevis 
muscles. It is smooth below and covered by the 
tendons of the same muscles. The posterior surface 
is flat for the origin of the Soleus muscle, and winds 
round the inner surface of the bone on its lower 
third, and is occasionally marked by a small nutri- 
tious foramen directed downward at about its middle 
third. The internal surface is divided by the ridge 
for the interosseous membrane into two narrow 
spaces, one lying between the ridge and the anterior 
border, yielding surfaces of origin for the Extensor 
Proprius Pollicis, the Extensor Communis Digitorum, 
and the Peroneus Tertius muscles, and the one lying 
between the ridge and the posterior border, wider 
and more depressed, designed for the origin of the 
Tibialis Posticus muscle. 
The lower extremity answers to the lower twisted 
portion of the bone. It begins at the point of greatest 
lateral compression, namely, where the internal border 
joins the ridge for the interosseous membrane. Beyond, 
the narrow elliptical portion has received, from some 
English writers, the name of the neck. The inner 
side is rough and marked by an elongated triangular 
surface for the strong fibres of the interosseous mem- 
brane. The outer surface is convex and subcutaneous. 
The lower extremity gradually increases in size as 
it approaches the corresponding extremity of the 
tibia where its distal end is called the external malleolus. 
Larger and more prominent than the internal malleolus, 
and, in articulation, placed a little posterior to it, the 
external malleolus resembles the lower third of the 
shaft, with which it is continuous in its wide lateral, 
and narrow antero-posterior surfaces. It is of a tri- 
angular shape, its antero-inferior border being some- 
what angulated. The posterior border is»thicker than 
the anterior, and is faintly grooved for the tendons of 
the Peroneus Longus and the Peroneus Brevis muscles. 
The anterior surface is convex and subcutaneous. 
The median surface presents a triangular articular 
facet, slightly convex from above downward for 
articulation with the astragalus, and at its upper 
portion with the tibia. Below and behind this facet 
is a roughened depression for the posterior fascicle of 
the external lateral ligament and the posterior fibres 
of the capsule. The summit is rounded for attach- 
ment of the middle fascicle of the external lateral 
ligament of the ankle-joint. 
Structure.-In the proximal end the main lines 
of the cancelli radiate from the articular surface and 
are intersected by concave transverse lines. Substan- 
tially the same arrangement obtains at the distal end, 
where the radiating fibres are notably conspicuous, 
and where they pertain more to the surface of con- 
tact with the astragalus than with the tibia. 
Development.-The fibula arises from three cen- 
tres of ossification: One for the shaft which appears 
at the sixth week; one for the lower extremity which 
appears at the second year; and one for the upper ex- 
tremity which appears at about the fourth year. The 
second named unites with the shaft at about the twen- 
tieth year, and the last at about the twenty-fifth. 
Remarks.-The fibula and tibia when seen in articu- 
lation present some striking features of contrast. Thus 
the shaft of the tibia is turned slightly forward, while 
that of the fibula is turned backward and outward. 
The shaft of the tibia is prismoidal with the base di- 
rected backward ; the shaft of the fibula is prismoidal 
with the base directed outward. The tibia extends 
proximally one inch beyond the fibula; the fibula ex- 
tends distally one inch beyond the tibia. The lower 
third of the tibia is slightly compressed from before 
backward ; the lower third of the fibula is greatly 
compressed laterally. 
The most superficial parts of the fibula are the head 
and the lower third of the shaft including the malleo- 
lus.-The head of the fibula lies on a level with the 
tubercle for the Quadriceps Extensor tendon. This 
becomes a valuable point for reference in conditions 
where the head is concealed by swelling of the sur- 
rounding soft parts. The lower third of the shaft 
together with the malleolus can always be defined 
beneath the skin, and owing to its peculiarly exposed 
position is liable to fracture. 
The place of insertion of the Biceps muscle some- 
times forms a conspicuous rounded projection at the 
base of the styloid process. 
The probable communication between the articular 
surface of the proximal end of the fibula and the knee- 
joint, as well as the proximity of important vessels 196 
THE BONES. 
thereto, should be constantly borne in mind by the 
surgeon. It is asserted by Knox that an operation of 
Liston's for excision of this portion of the bone re- 
sulted in death from hemorrhage. Examples are on 
record of death from pyarthrosis following the same 
operation, as well as from the removal of tumors 
involving the head of the fibula. 
In talipes varus the fibula may touch the calca- 
neum and effect a joint therewith. In atrophy of the 
peroneal muscles, notably that of the Peroneus Longus, 
the eminence of the external malleolus becomes un- 
duly prominent.-Osteophytes are specially liable to 
form at the median margin of the shaft above the 
distal articular surface. 
The mechanism of the deformity of fracture of both 
malleoli is, according to Dr. Gordon Buck,1 as follows : 
When both malleoli are fractured, the tibia tends 
to slide forward so that only the posterior half of the 
articular surface rests upon the articular surface of 
the astragalus. The dorsum of the foot is hereby 
shortened and the heel projects backward. The lower 
part of the leg presents a remarkable curve with its 
convexity forward. The same authority2 describes a 
specimen of necrosis of the tibia, in a child twelve 
years of age, in which a sequestrum extended through 
the distal end of the tibia into the ankle-joint, which 
was anchylosed. The specimen was mainly interest- 
ing from the circumstance that the process of necrosis 
was not limited to the compact portion of the bone, 
but had fairly extended into the spongy portion. 
the patella. 
The patella (figs. 6, 7, Plate XXXIV.) or knee-cap 
is a sesamoid bone lodged in the tendon of the Quad- 
riceps Extensor Cruris muscle. It is subcutaneous, 
and can be easily distinguished in the undissected 
subject. It is movable when the leg is extended, but 
fixed against the trochlea and external condyle of the 
femur when the leg is flexed. It is broader than 
long, sub-triangular in form with its thickened rugose 
base directed proximally to receive the tendon of the 
Quadriceps. The apex is in connection with the 
ligamentum patellae. 
The patella presents for examination an anterior 
and a posterior surface, and a median and a lateral 
border. The anterior surface is faintly convex in all 
directions, and is marked with linear striae and grooves, 
as well as with a few nutritious foramina. The posterior 
surface is concave from above downward, and concavo- 
convex from side to side. It is covered with carti- 
lage for articulation with the femur. A ridge-like 
eminence extends a little to the median side of the 
middle line downward and inward. The lateral facet 
is concave, and larger than the median, which is ob- 
scurely convex. The borders are slightly emargi- 
nated superiorly, but convex inferiorly. The apex of 
the bone projects downward to a distance equalling 
nearly one-fourth the length of the articular surface. 
The base of the patella is broader behind than in 
front. The lateral margin is thin and subtruncate; 
the median is evenly rounded. 
Structure.-The patella, when sawn open from 
side to side, shows an evenly textured surface. The 
cancelli are small, save at the apex, where they are 
coarse and uneven. 
Development.-The patella arises by a single cen- 
tre of ossification, which appears at the third month. 
Remarks.-The most important fact to be remem- 
bered in connection with the patella is its disposition 
to transverse fracture. This occurs either from mus- 
cular violence, or from falls upon the flexed knee when 
the patella is fixed against the patellar groove of the 
femur and the external condyle. 
The Quadriceps muscle, by drawing the upper 
fragment away from the lower, creates a deep trans- 
verse sulcus. In place of a depression an elevation 
of the interosseous space may occur, an effect attrib- 
uted by Jonathan Hutchinson1 to the outward pres- 
N. Y. Med. Joum., iii., 1866, 41. 2 Ibid., 44. 
1 Med. Chir. Trans., lii. 340. 
EXPLANATION OF PLATE XXXIV 
Fig. 1. The tibia, seen from in front. 
Fig. 2. The tibia, seen from the lateral side. 
Fig. 3. The tibia, seen from behind. 
Fig. 4. The fibula, seen from the median side. 
Fig. 5. The fibula, seen from the lateral side. 
Fig. 6. The patella, seen from in front. 
Fig. 7. The patella, seen from behind. PLATE XXXIV 
Fig 5 
?ig 4 
Fxg ? 
Fig. € 
Fig 7 
Fig. 2 
Fig 1 
T.Sinclair & Son.lift. THE BONES OF THE FOOT. 
197 
sure of the synovial fluid of the joint. Union is 
almost always fibrous. Indeed, according toD. Hayes 
Agnew,1 such a union is to be desired, since a true 
osseous union is liable to be destroyed. 
The Bones of the Foot. 
The bones of the foot (Plate XXXV.) are composed 
of the calcaneum, the astragalus, the cuboid bone, 
the scaphoid bone, and the three cuneiform bones, 
composing the tarsus; of the first, second, third, 
fourth, and fifth metatarsal bones, composing the me- 
tatarsus ; and of the two toe-bones of the first toe and 
the three toe-bones in each of the remaining toes, 
that collectively constitute the phalanges of the foot. 
THE TARSUS. 
The Calcaneum.-The calcaneum (os calcis) is the 
largest bone of the tarsus, and constitutes the posterior 
abutment of the longitudinal arch of the foot. The 
shape of the bone is that of an elongated cube whose 
upper surface is irregularly depressed, and whose me- 
dian surface is concave. The calcaneum articulates 
above with the astragalus, and in front with the 
cuboid bone. The bone is composed of a body and an 
anterior process. The hody comprises the bulk of the 
bone, namely, the portion answering to the surface of 
articulation with the astragalus and the laterally com- 
pressed mass projecting backward from it to form the 
"heel." The anterior process is that portion of the 
calcaneum lying in front of the articulating surface for 
the astragalus, and it serves to articulate with the cu- 
boid bone.-An imaginary line, passing round the heel 
directly behind the posterior margin of the ankle, 
indicates the so-called "neck" of the calcaneum. 
In a more exact manner the calcaneum is described 
by its surfaces ; these are six in number, as follows :- 
The superior surface is divided into a posterior 
concave roughened surface which is free, and an 
anterior smooth surface for articulation with the as- 
tragalus. The last named is again divided into an 
anterior and a posterior portion, with an intervening 
depression. The anterior portion is elongated, con- 
cave, with sinuate margins; in front, as it overhangs 
the cuboidal face, a separate surface is often developed. 
The posterior portion is larger than the anterior, is 
sub-rounded, and looks downward and outward. It 
is supported by the stout process which has received 
the name of the sustentaculum tali. The depres- 
sion between the two portions is narrow within, 
broad without, and yields attachment for the interos- 
seous calcaneo-astragaloid ligament. When the cal- 
caneum is in articulation with the astragalus, this 
depression is converted into a canal.-The inferior 
surface is narrowed from behind forward, and is 
marked at its posterior third by two tubercles named 
from their relative positions the median and the lateral 
tubercle, the former of which is much the larger. 
Probably the lateral tubercle sustains little or none 
of the weight of the body, since it is of merely mus- 
cular significance. It forms a round projection when 
seen from the lateral surface of the bone. Both tuber- 
cles afford points of attachment for the correspond- 
ing divisions of the plantar fascia, while the interval 
between them yields a surface of origin for the Flexor 
Brevis Digitorum. In front, on the median margin of 
the inferior surface, is a broad, slightly convex surface 
for attachment of the stout greater inferior calcaneo- 
cuboid ligament. The mechanical axis of the infe- 
rior surface of the calcaneum appears to lie ob- 
liquely to the anterior tubercle, for the attachment 
of the lesser inferior calcaneo-scaphoid ligament, in- 
ward and backward to the median tubercle, thus 
placing the lateral tubercle paraxially.-The lateral 
(external) surface is nearly vertical, and marked with 
numerous openings for bloodvessels. Placed near its 
middle is a welk-like rugosity, which, from the circum- 
stance that it serves to separate the Peroneus Brevis 
from the Peroneus Longus muscle, is known as the 
peroneal tubercle. A second tubercle is situated near 
the cuboidal facet, and gives origin to the Abductor 
Minimi Digiti. In articulation it is a guide to the 
position of the calcaneo-cuboid joint.-The median 
(internal) surface (hollow of the calcaneum) is con- 
cave for the protection of the tendons of the posterior 
tibial muscles, and the plantar bloodvessels. The 
Flexor Longus Pollicis tendon lies in the best defined 
groove of the bone on the under surface of the susten- 
taculum tali.-The anterior surface is lozenge-shaped ; 
the upper three-fourths of the space is occupied by 
an articular surface for the cuboid bone, and is tri- 
angular in form, the apex being directed upward. 
The facet is slightly convex laterally, but is concave 
medianly to form at the upper margin a conjunction 
with the astragalar articular surface. The lower angle 
of the anterior surface is roughened for the attachment 
of the inferior calcaneo-scaphoid ligament.-The pos- 
terior surface (calcaneal tuberosity, tuber calcis) is 
blunt and free. The upper portion inclines forward, 
and is covered with a bursa; the lower is roughened 
for the insertion of the tendo Achillis. 
1 System of Surgery, i. 980. 198 
THE BONES. 
Structure.-The calcaneum presents a stout layer 
of compact tissue beneath the posterior astragalar 
articular surface and the depression in front of it; a 
second at the inferior surface by the bone directly 
beneath the foregoing; a third in the sustentaculum 
tali ; and a fourth, much weaker, at the cuboidal sur- 
face. Elsewhere the interior is cancellous, and is 
composed for the most part of beautiful curved lines 
arranged in two sets, one extending from the cuboidal 
surface to the tuberosity, and concave upward; and 
the other ranging from the posterior astragalar sur- 
face to the tuberosity, and concave downward. A 
third set of radiating laminae passes from the de- 
pression for the calcaneo-astragaloid ligament forward 
to the cuboidal surface. The laminae at the upper 
half of the bone are coarser than those at the lower 
half. 
Remarks.-In talipes equinus the calcaneum is 
slightly raised, and assumes an oblique position. 
The degree of the elevation is more apparent than 
real, and is, indeed, more marked in equino-varus 
than in true equinus. The bone may be in con- 
tact with the tibia behind. In talipes varus the 
calcaneum is drawn upward by the ' Gastrocnemius 
and Soleus muscles, and occupies a very oblique, al- 
most vertical position, with a slight inclination in- 
ward. The calcaneum in the new-born child presents 
a smaller portion of the astragalar surface upon the 
outer aspect of the bone than in the adult.1 The 
sustentaculum tali is enlarged in acquired talipes val- 
gus; but is relatively small in talipes varus. Necro- 
sis attacks the calcaneum with relative frequency. 
The centre of ossification has been lost by necrosis in 
a child aged three years, as in a case reported by Mr. 
Birkett.2 Necrosis of the tibia of the corresponding 
side ensued. 
Geo. Buchanan3 reports a case of excision of the 
calcaneum. 
The Astragalus.-The astragalus is, next to the 
calcaneum, the largest bone in the tarsus. It is 
placed between the bones of the leg above, the calca- 
neum beneath, and the scaphoid bone in front. It is 
irregularly cubical in shape, and, as usually stated, is 
composed of a body, a head, and a neck. The body 
answers in a general way to the surfaces of contact 
with the bones of the leg and the calcaneum, as well 
as to those occupied by the ligaments attached to the 
astragalus. The head is a synonym for the articular 
surface for contact with the scaphoid bone and the 
inferior calcaneo-scaphoid ligament. The neck is the 
constriction between the body and the head. It is 
better defined laterally (where it is narrow and de- 
pressed) than medianly (where it is broad, and makes 
up part of the median border of the foot) or infe- 
riorly (where, indeed, its line bisects the calcaneal 
articular surface.) 
In a more exact manner the astragalus is said to 
be made up of six surfaces: the superior, the inferior, 
the anterior, the posterior, and the two lateral sur- 
faces. 
The superior surface is for the most part occupied 
by the large facet for articulation with the axial distal 
surface of the tibia. It is narrower behind than in 
front; concave near the centre, but convex toward the 
two sides, the lateral side being the wider. In advance 
of the facet the superior surface includes the de- 
pressed proximal aspect of the neck.-The inferior 
surface is very irregular, and embraces three facets 
and a deep groove. The posterior facet for the cor- 
responding posterior facet of the calcaneum is con- 
cave, broader behind than in front. It is obliquely 
placed to the axis of the bone, and, with reference to 
this axis, is disposed in the main to the lateral side. In 
front lies a deep groove for the attachment of the in- 
terosseous astragalo-calcaneal ligament. The remain- 
ing facets are contiguous in front of the groove, and 
include the oval surface for articulation with the ante- 
rior calcaneal facet, and a small ribbon-shaped facet 
(the head in part) for articulation with the inferior 
calcaneo-scaphoid ligament.-The anterior surface 
(the head in part) is an oblong, convex surface, whose 
longest diameter lies nearly at a right angle to the 
axis of the bone, but with an inclination downward 
and inward. It articulates with the scaphoid bone.- 
The posterior surface is a roughened, narrow ledge 
intervening between the tibial and the calcaneal 
articular surfaces. It is grooved toward the median 
side for the tendon of the Flexor Longus Pollicis. 
This groove is a valuable sign by which the surgeon 
can identify the astragalus in backward dislocation 
of this bone.-The median surface (inner) is irregu- 
lar, and inclined a little inward. It is marked 
above, where it joins the superior surface at an angle, 
by a pear-shaped articular facet, for articulation with 
the internal malleolus. The base is directed forward, 
and lies in advance of the lateral articular facet. 
Below and behind this facet is the roughened surface 
for the attachment of the deltoid ligament. The 
median surface forms a well-defined limitation to the 
1 Huetter, Langenbeck's Archiv, iv., 1863, 475. 
2 Trans. Path. Soc. Lond., vi., 1856, 288. 
3 Edinburgh Med. Journ., 1876, 869. THE BONES OF THE FOOT. 
199 
neck anteriorly.-The lateral surface (outer) is in 
great part occupied by a facet. This is of a triangu- 
lar shape, whose convex base is proximal, and whose 
apex is directed slightly outward. In advance of 
the lateral surface is a depression for the anterior 
lateral ligament; while behind lies a groove for the 
posterior lateral ligament. In front of the facet the 
surface is directed obliquely outward and forward, to 
form the lateral boundary of the neck. At a corre- 
sponding point beneath is the notch for the inter- 
osseous ligament. Behind, is the edge of the surface 
articulating with the body of the calcaneum. 
To ascertain the side to which the astragalus 
belongs, place the bone with the superior facet up- 
ward ; the side on which the neck is least defined will 
indicate the side to which the bone belongs; or, the 
position being the same, the external malleolar facet 
will point toward the side to which the bone belongs. 
Structure.-The borders of the neck, both above 
and below, present a little compact tissue; elsewhere 
the bone is spongy. The lines of the laminae are ar- 
ranged in four sets. The first is composed of those 
finely textured cancelli underlying the proximal 
articular surface, and composing the bulk of the 
body of the bones; the second, of those passing from 
the posterior calcaneal surface, to join the first group; 
the third, of those stout, coarse lines extending 
directly backward from the scaphoid articular surface 
(the head) through the neck, to end abruptly against 
the first; and the fourth, of those weak lines passing 
obliquely upward and backward from that portion of 
the head in articulation with the inferior calcaneo- 
scaphoid ligament. The astragalus is weakest at the 
neck, where alone the third set of laminae exists; it 
is here that the bone is most frequently fractured. 
Remarks.-The changes in the foot after excision of 
the astragalus, together with the lower end of the fibula, 
in an instance recorded by Erichsen,1 were as follows : 
The foot was drawn up by the tendon of the Tibialis 
Anticus muscle, and was slightly everted, forming a 
variety of talipes equinus. In another case of ex- 
cision2 the patient was able to walk three months 
afterward. The malleoli necessarily rest upon the 
calcaneum or the scaphoid bone. It is probable that 
in time a new joint may be formed between them and 
the bones of the leg; or anchylosis may ensue, as was 
found to be the case by E. Bellamy.3 The power of 
adduction and abduction, of the foot in this condi- 
tion, would be greatly impaired; as would also be 
the motions of the medio-tarsal joint. - Notwith- 
standing the preservation of all important muscular 
attachments, any sudden or violent attempt to throw 
the weight of the body upon the affected foot 
is liable to induce backward dislocation of the 
foot; the only force present resisting this tendency 
being the released fibulo-calcaneal and tibio-calcaneal 
ligaments.-After a careful study of three subsequent 
histories of removal of the astragalus for dislocation, 
J. Tufnell1 concludes that a useful foot, such as would 
enable a laboring man to earn a livelihood, is not to 
be expected. 
Mr. Wm. MacCormac2 thus describes the position 
of the astragalus after a fracture and dislocation of 
the bone, of two years' standing: "The neck of the 
astragalus was fractured, the detached head remaining 
connected with the scaphoid ; while the larger portion, 
or body of the bone, was completely displaced from 
between the malleoli backward and inward with a 
species of double rotation, so that the superior artic- 
ulating surface was almost vertical, looked inward 
and slightly backward, and had the tendon of the 
Flexor Longus Pollicis fixed to it The 
internal malleolus had been fractured, and between it 
and the inner border of the astragalus lay the tendons 
of the Tibialis Posticus and Flexor Longus Digitorum 
muscles." 
The same author describes a second case thus: 
" The tibial surface was superficial, looking inward 
and slightly upward; the posterior extremity was 
directed downward toward the os calcis. Reduction 
could not be effected. The limb thirteen years after- 
ward still exhibited the deformity as described. The 
man had very considerable movement in the ankle, 
and a slight degree of lameness was alone present." 
In congenital talipes varus the shape of the astra- 
galus is materially modified. The neck is longer than 
usual, and is more obliquely placed from without in- 
ward than in the normal bone. The head, in addition 
to its articulation with the scaphoid toward the 
inner border of the foot, is in part free beneath the 
skin of the dorsum of the foot. The superior artic- 
ular surface at the ankle extends quite to the poste- 
rior edge of the bone, and is thin and wedge-shaped, 
instead of being obtusely rounded. The groove for 
the Flexor Longus Pollicis is absent. 
In talipes equinus the astragalus inclines forward, 
in which direction it may be partially dislocated. In 
1 Med. Times and Gaz., Mar. 1860, 317. 
2 Med. Times and Gaz., Mar. 20, 1860. 
3 Trans. Path. Soc. Lond., 1873, 172. 
1 Dublin Medical Press, Dec. 28, 1853. 
2 Trans. Path. Soc. of Lond., 1875,174. 200 
THE BONES/ 
talipes valgus, either congenital or acquired, the 
head of the bone can be easily defined under the 
skin, owing to the relaxed condition of the ligaments. 
The inner border of the head is very prominent. 
Hueter has pointed out the fact that the neck of 
the astragalus in the infant is relatively longer than 
in the adult, and presents a nearly transverse scaphoid 
articular surface. 
The astragalus is the only bone in the tarsus with- 
out muscular attachment. 
The Cuboid Bone.-The cuboid bone is of an 
irregular cuboidal figure, broader behind than in front, 
and verging to the pyramidal form, since all its 
surfaces, excepting the median, slope toward the com- 
pressed lateral border. It is situated to the outer side 
of the foot, with the calcaneum behind, the fourth 
and fifth metatarsal bones in front, and the external 
cuneiform and scaphoid bone to the median side. 
It presents six surfaces for examination. The supe- 
rior surface is smooth, and covered by the Flexor 
Brevis Digitorum. The inferior (plantar) surface .is 
grooved obliquely for the tendon of the Peroneus 
Longus; behind the groove is a broad tubercle for 
the attachment of the greater inferior calcaneo-cu- 
boid ligament. At the proximo-median angle is a 
rugosity for the attachment of the lesser inferior 
calcaneo-cuboid ligament. The lateral surface is 
grooved obliquely for the Peroneus Longus muscle 
prior to its entering the plantar groove. The me- 
dian surface is flat, and marked with an oval facet for 
articulation with the external cuneiform bone, and 
commonly by a facet contiguous with the foregoing 
for the scaphoid bone. It is also roughened for the 
attachment of ligaments. The distal surface is sub- 
triangular, and divided by a vertical ridge into two 
facets for the articulation of the fourth and the fifth 
metatarsal bones. The proximal surface is concave 
vertically, and convex from side to side to artic- 
ulate with the calcaneum. Holding the bone with 
the grooved under surface downward, and the concave 
articular surface backward, the compressed border 
marked by the groove for the Peroneus Longus muscle 
will point to the side to which the bone belongs. 
The Scaphoid Bone.-The scaphoid or navicular 
bone is placed on the inner side of the foot, having 
the astragalus behind it, the cuneiform bones in 
front, and the cuboid bone to the lateral side. It is 
compressed from behind forward, thicker below 
than above, and slightly inclined from beneath 
upward and outward. Above, the proximal surface 
is concave and pear-shaped, for articulation for the 
most part with the head of the astragalus. The 
anterior surface is curved transversely, and divided 
by two faintly marked, diverging ridges, defining 
three facets for articulation with the correspond- 
ing cuneiform bones. The median surface is broad, 
free, and somewhat roughened for the attachment 
of ligaments. The lateral surface is compressed, and 
commonly presents an uneven surface for articula- 
tion with the cuboid bone. The inferior surface is for 
the most part occupied by a pronounced tuberosity for 
the insertion in part of the Tibialis Posticus muscle. 
To the outer side of this prominence lies a narrow 
surface for the attachment of the inferior calcaneo- 
scaphoid ligament. According to Cruveilhier, the 
tuberosity may be greatly enlarged, and has been 
mistaken for an exostosis. It serves as a guide to the 
astragalo-scaphoid articulation. Holding the bone 
with the concave surface toward the observer, and the 
thickened end down, the narrow, roughened, lateral 
surface will point toward the side to which the bone 
belongs. 
Remarks.-In pronounced talipes varus the tuber 
rosity is in contact with the inner malleolus. The 
long axis of the bone is parallel with the long axis 
of the leg, instead of being at right angles to it. In 
talipes equinus, the scaphoid is drawn somewhat 
toward the plantar surface. 
The Cuneiform Bones.-The three cuneiform 
bones are so named from the resemblance each bears 
to the figure of the wedge. They are lodged between 
EXPLANATION OF PLATE XXXV. 
Fig. 1. The bones of the foot in articulation, seen from 
above. 
Fig. 2. The bones of the foot in articulation, seen from 
beneath. 
Fig. 3. The bones of the foot in articulation, seen from the 
median side. plate XXXV 
Fig. 3 
Fig. 2 
Fig 1 
FiS • 87 
T.Sinclair & Son.lifh. THE BONES OF THE FOOT. 
201 
the scaphoid bone behind, and the first, second, and 
third metatarsal bones, respectively, in front. 
With the internal (first) cuneiform the form of the 
wedge is obscured by having the convex base directed 
downward. The sides of the bone being curved, and 
the apex irregular, the bone projects distally nearly 
one-half its length beyond the second. The median 
surface is free, roughened, unequally convex, and 
marked below by a smooth surface for the tendon of 
the Tibialis Anticus muscle. The lateral surface is 
concave, and for the most part is markedly roughened 
for the attachment of ligaments, but faceted above for 
articulation with the middle cuneiform bone and the 
second metatarsal bone. Its proximal surface is pear- 
shaped, and presents a concave articular surface whose 
base is directed downward for articulation with the 
scaphoid bone. Distally a kidney-shaped facet is seen, 
its notch lying to the outer side, for articulation with 
the first metatarsal bone. The upper portion of the 
bone is angulated, and is thicker before than behind. 
The inferior portion is free, and projects conspicuously 
below the plane of the other cuneiforms to form the 
tuberosity which receives the tendon and attachment 
of the Tibialis Posticus and a portion of the Tibialis 
Anticus muscles. Holding the bone with its large 
end downward, the notch in the anterior facet will 
point to the side to which the bone belongs. 
The middle (second) cuneiform, the smallest of the 
three, resembles a wedge to a greater degree than does 
either of the other cuneiforms. It is quadrangular on 
the dorsal surface, slightly narrow toward the distal 
end, and tapers at the plantar surface to a thin edge. 
The distal surface, designed for articulation with the 
second metatarsal bone, is broader below than the 
proximal which articulates with the scaphoid bone. 
The median surface is faceted at the upper half and 
along the proximal margin for the first cuneiform 
bone. The lateral surface articulates posteriorly and 
superiorly with the external cuneiform. Holding 
the bone with the broad end upward and the smaller 
end forward, the side with the smaller facet will point 
to the side to which the bone belongs. 
The external (third) cuneiform recalls the general 
shape of the preceding, but is readily distinguished 
therefrom by its greater size, and by retaining the axis 
of the proximal articular surface at an angle to that 
of the distal. The bone projects about one-fourth its 
length distally beyond the middle cuneiform. The 
distal facet for the third metatarsal bone is longer than 
the proximal for the scaphoid bone, which in its turn 
is oblique from without inward, and from behind 
forward, and concave beneath where it yields a rough- 
ened surface for the attachment of ligaments. Later- 
ally the third cuneiform presents at the junction of 
the dorsal and proximal margins a facet for artic- 
ulation with the cuboid bone, and occupies about one- 
fourth of the lateral surface. Occasionally it presents 
a small facet at the dorsal edge of the distal border for 
articulation with the fourth metatarsal bone. Median- 
ly the bone is depressed in the centre, and presents a 
roughened surface with two facets; the proximal of 
which articulates with the middle cuneiform, and the 
distal with the second metatarsal bone. Holding the 
bone with the base upward and the oblique facet 
backward, the lateral surface will point to the side to 
which the bone belongs. 
Remarks.-Dislocation of the second and third 
cuneiform bones on the dorsum of the scaphoid is 
described by Hancock.1 The bones were excised, and 
the patient, a boy fourteen years of age, recovered. 
The bones of the tarsus are exceedingly liable to 
caries. Direct injuries except those arising from 
crushing degrees of force are infrequent. Small ex- 
ostoses are not rarely seen on the dorsal surface of the 
first cuneiform. 
THE METATARSUS. 
The metatarsal bones are five in number, arranged 
in a transverse arch between the row formed by the 
cuboid and the cuneiform bones behind, and the pha- 
langes in front. Each bone consists of a shaft and of 
a distal and a proximal extremity. The shaft is of 
a prismoidal form, and is more or less -compressed 
laterally. The distal surface is convex, and the proxi- 
mal flat or slightly concave. 
The metatarsal bones are divided into those articulat- 
ing with the first, the second, and the third cuneiform 
bones, and those articulating with the cuboid, namely, 
the fourth and the fifth. In each of the former group 
a line drawn along the dorsum, from the middle of the 
distal surface, will pass through the middle of the proxi- 
mal surface. In the latter a line drawn from the same 
point as above will be directed to the outer margin of 
the bone before reaching the proximal surface.-The 
first bone of the series is the most massive. Its proxi- 
mal surface is kidney-shaped with the notch directed 
outward, and is placed at right angles to the longitudi- 
nal axis of the bone. The distal surface, while convex 
and smooth above, is marked below by a median ridge 
defining two grooves, one on either side, for articula- 
1 Anat, and Surg. of the Unman Foot, 1873, 95. 202 
THE BONES 
tion with the sesamoid bones.-The second is the long- 
est of the series. It possesses a slightly concave tri- 
angular proximal facet whose apex is directed down- 
ward. It presents a roughened, flattened tubercle on 
the lateral side for ligamentous attachment with the 
third metatarsal bone. On the same surface the artic- 
ular surface is divided into two facets by a sulcus. 
-The third possesses a proximal, flat, triangular 
surface. The lateral surface for ligaments is con- 
vex. The articular facet on this side is somewhat 
triangular; the dorsal border is nearly straight; the 
groove beneath the single facet is well defined.-The 
fourth metatarsal presents a proximal articular surface 
which is triangular; its apical portion is depressed, 
so that the surface has the appearance of having two 
facets. The external facet for articulation with the 
fifth metatarsal is triangular, with a convex dorsal 
border; the groove is very well defined.-The fifth 
metatarsal bone possesses a compressed shaft whose 
proximal surface is flat or oblique. The median sur- 
face is large, with a small ridge on the proximal 
border, which is received within a groove upon the 
lateral surface of the fourth metatarsal. The lateral 
border is prolonged into a process proximally near 
the plantar surface, but separated from the articular 
surface by a groove. 
Synoptical Table of the Metatarsal Bones. 
The axis of the dorsal aspect of the distal surface cuts the proximal surface of the first, the second, and the third metatar- 
sal bones, as they articulate with the cuneiforms. 
Without lateral facets, and possessing grooves for the sesamoid bones on the distal surface. The proximal surface is 
reniform, with its dorsal border arranged transversely to the longitudinal axis ....... First. 
With facets on either side of the proximal extremity Second, third, fourth. 
The external lateral surface with faintly marked groove, and flatfish tuberosity; proximal surface triangular, 
concave Second. 
The external lateral surface with facet concave, dorsal border straight; the groove is narrow, defined ; the tube- 
rosity pronounced ; proximal surface triangular and flattened ......... Third. 
The axis of the dorsal aspect of the distal surface does not cut the proximal surface of the fourth and the fifth metatarsal bones 
as they articulate with the cuboid. 
The lateral surface flat with convex dorsal borders ; the groove deep, the tuberosity pronounced. The proximal 
surface triangular with apical third depressed Fourth. 
The facet on proximal end on one side only (median), external tubercle large Fifth. 
THE PHALANGES. 
These agree with the characteristics of the corre- 
sponding bones of the hand to such a degree that little 
need be said in detail in this connection. 
The most marked peculiarities are the following :- 
The phalanges of the first toe are relatively larger 
than the same bones of the hand, while those of the 
remaining toes are relatively smaller. The shafts of 
the bones, excluding those found in the great toe, are 
more compressed laterally. The phalanges of the 
fourth and fifth middle toes, as well as the first pha- 
lanx of the great toe, are apt to be deformed in the 
skeletons, as seen in our cabinets, by reason of the 
almost universal practice of wearing ill-fitting shoes. 
The sesamoid bones are placed on each side of the 
plantar surface of the distal end of the first metatarsal 
bone. They are osseous developments within the 
tendons of the Flexor Brevis Pollicis. They are 
faceted on their dorsal, but are free and roughened 
on their plantar surfaces. They can be felt obscurely 
beneath the skin in the undissected subject. 
THE FOOT. 
When the bones of the foot are in articulation with 
each other an elongated figure results, which is nar- 
row and compact behind; broad and spreading in 
front; convex above, but concave, irregular, or flat 
below. 
The bones of the tarsus are arranged in rows, with 
the exception of the astragalus which overlies the 
calcaneutn. The distal surfaces of both the last- 
named bones advance to nearly the same level, and 
form the proximal surfaces of the medio-tarsal joint, 
to which the scaphoid and the cuboid bones con- 
tribute the distal surfaces. The tarsal (in advance of 
the medio-tarsal line) and the metatarsal bones are 
more or less arched transversely (frontally). The 
tarso - metatarsal joint is curved forward, and the 
median end is advanced beyond the lateral. The 
proximal end of the second metatarsal bone is sunk 
in a depression called the mortise, between the first 
and the second metatarsal bones. The phalanges are 
arranged in a nearly flat series, and present proximal THE BONES OF THE FOOT. 
203 
surfaces on a single line, save the fifth alone, which 
is advanced proximally beyond that of the others. 
Among the remaining parts defined by the union 
of the bones, but absent or not well seen in the iso- 
lated bones, may be mentioned the following:- 
The canal that is formed between the astragalus 
and the calcaneum. 
The oblique groove extending across the plantar 
surface from the lateral border of the cuboid bone, 
forward and inward; this is the peroneal (plantar) 
groove for the accommodation of the tendon of the 
Peroneus Longus muscle. 
An eminence at the dorsal surfaces of the first and 
second cuneiform bones that has received the name 
of the instep. 
The portion of the calcaneum projecting poste- 
riorly to the astragalus and forming the " heel." Du- 
chenne1 describes the heel as the "arri^re pied," as 
opposed to the foot in advance of the ankle, which 
he calls the " avant pied." 
Interosseous spaces are formed between the meta- 
tarsal bones and the phalanges. Of these the space 
between the bones of the first and the second of the 
series is the widest. 
The median border of the plantar surface is robust 
distally, and ends abruptly with the scaphoid proxi- 
mally. The lateral border of the same surface is 
weak distally, but becomes increasingly robust proxi- 
mally, to end in the enormous median plantar tubercle 
of the calcaneum. 
The bones of the foot are arranged in two longi- 
tudinally disposed series-a median and a lateral. 
The median series is composed of the phalanges of 
the first, the second, and the third toes, and of the meta- 
tarsal and tarsal elements with which these articulate. 
The lateral series is composed of the fourth and fifth 
toes and of their respective metatarsal and tarsal bones. 
Seen in a tabular form the arrangement is easily fol- 
lowed. 
A Table of the Bones of the Foot arranged in Longitudinal Series. 
I. 
1st phalanx 
I 
2d phalanx 
I 
1st metatarsal 
I 
1st cuneiform 
II. 
1st phalanx 
2d phalanx 
I 
3d phalanx 
2d metatarsal 
2d cuneiform 
III. 
1st phalanx 
2d phalanx 
3d phalanx 
3d metatarsal 
3d cuneiform 
IV. 
1st phalanx 
2d phalanx 
3d phalanx 
4th metatarsal 
V. 
1st phalanx 
2d phalanx 
3d phalanx 
5th metatarsal 
Scaphoid 
Cuboid 
Astragalus 
Calcaneum 
When the weight of the body rests upon the 
flexed lower extremity, and the heel is elevated, the 
tibia is inclined forward upon the widest portion of 
the superior articular surface of the astragalus; the 
greater part of the weight is thus transmitted through 
the last named bone to the median series of the foot 
as far as the metatarso-phalangeal joints, beneath 
which in the living subject is the callous pad, the 
ball of the toes. Along this line the articular sur- 
faces of the bones are composed of proximal convexi- 
ties resting within distal concavities-in a word, of 
a series of segments of balls resting within partial 
sockets. The weight is in part sustained by the 
plantar ligaments.-The lateral series in this position 
has but slight work to do, viz., to act as a crutch 
to the median.-When the weight of the body is 
borne by the extended lower extremity, the foot rests 
firmly on the ground, and the weight is in part trans- 
mitted from the astragalus to the calcaneum, and 
thence to the cuboid bone and the bones of the fourth 
and the fifth toes. The median series receives, how- 
ever, much of the weight of the body by means of the 
head of the astragalus resting in this position in the 
concavity of the scaphoid bone, and on the inferior 
calcaneo-scaphoid ligament. The impress of the foot 
is greater on the lateral than on the median side.1 
According to F. 0. Ward,2 the attitude first described 
is employed to distribute the force of sudden con- 
cussion, as from a jump; the second posture is as- 
sumed when the foot is required to sustain some 
heavy continuous pressure, that of the trunk for 
instance, augmented, as it often is, by the addition 
of a ponderous burden. 
1 Boston Medical and Surgical Journal, xc. 48. 
2 Outlines of Osteology, 367. 
1 Physiologic des Mouvements. 204 
THE BONES 
The tarsal and the proximal ends of the metatarsal 
bones of the median series, excepting the astragalus, 
tend to form wedges (least pronounced in the sca- 
phoid) whose bases are either dorsal or plantar; 
while those of the median series are wedges whose 
bases are lateral (least pronounced in the fourth 
metatarsal). The plantar surface of the median series 
is acutely arched at the tarsus and the metatarsus, 
while the plantar surface of the lateral series is flat. 
It is of interest to note that wounds of the lateral 
series are less severe than those of the median. 
In addition to the disposition of the bones above 
noted, the foot, when studied as a separate mechanism, 
yields two principal arches-the longitudinal and 
transverse-which are arranged to sustain the weight 
of the body, and to protect the plantar nerves and 
bloodvessels. The longitudinal arch is not an exact 
figure, since it is composed of the oblique line extend- 
ing from the ball of the foot to the summit of the 
astragalus, and thence, by an abrupt descent, to the 
external plantar tubercle of the calcaneum. The 
transverse arch is best defined at the medio-tarsal 
joint, between the plantar surface of the first cunei- 
form bone and the lateral border of the cuboid. 
Both the longitudinal and the transverse arches are 
subject to modification. The formation of the trans- 
verse arch depends upon the ability of the bones 
composing it to be accurately adjusted by pressure; 
upon the degree and the kind of motion permitted 
between the bones; upon the nature of the connecting 
ligaments, as well as the lines of traction of powerful 
muscles. When the arch is relieved from the strain 
of the weight of the body, it assumes a narrow and 
high position; but when it sustains the weight of the 
body, it tends to become flattened, and would be 
obliterated were it not for the weight forcing the 
lateral and the median ends of the arch to the sides, 
at the same time that the dorsal approximal angles 
of the bones are tilted toward each other. As the 
arch is thus retained, the ligaments and the tendons 
of muscles passing between the plantar surfaces and 
the corresponding surfaces of the other bones be- 
come tense and limit the degree of motion. 
The muscles that sustain the arch are the Tibialis 
Anticus, the Tibialis Posticus, and the Peroneus 
Longus. When, apart from the condition of the 
bone, softening of the ligaments or paralysis of the 
muscles ensues, the efficacy of the arch is impaired, 
and may be destroyed. Flat foot and various pseudo- 
neuralgic conditions may result from such failure of 
action. 
Development.-The tarsal bones ossify after the 
following method : Each arises from a separate centre, 
except the calcaneum, which retains an epiphyseal 
centre at the surface of attachment of the tendo 
Achillis. The calcaneum receives its bony nucleus 
at the sixth month; the astragalus at the seventh 
month; the cuboid at the ninth month; the third 
cuneiform at the first year; the internal cuneiform 
at the third year; and the scaphoid and middle 
cuneiform at the fourth year. The calcaneal epi- 
physis joins the body of the bone at the tenth year. 
Gruber1 reports a case in which the portion of the 
astragalus accommodating the tendon of the Flexor 
Longus Pollicis existed as a distinct ossicle. 
The metatarsal bones and the phalanges develop 
after the method of the similar parts in the hand. 
Each bone presents a single nucleus for the shaft or 
body, and one for an epiphysis. The epiphyseal nucleus 
is distal in the metatarsal bones from the second to 
the fifth, but is proximal in the first. The epiphyseal 
nucleus is proximal in all the phalanges. The order 
of ossification is as follows: In the metatarsal bones 
the nuclei of the shafts appear in the eighth or ninth 
week. The epiphyses appear from the third to the 
eighth year, and unite with the shafts from the 
eighteenth to the twentieth year. The nuclei of the 
shafts of the phalanges appear in the ninth or tenth 
week. The epiphyses appear from the eighth to the 
tenth year, and unite with the shafts from the nine- 
teenth to the twenty-first year.2 
1 Archiv. Anat., Physiol., und Wissensch. Medecin., 1864, 286. 
2 Quain's Anatomy. THE JOINTS AND THE LIGAMENTS. 
A Capsular Ligament is a bag of fibrous tissue 
holding the apposed ends of bones together. It forms 
the foundation of the movable joint. It is uneven 
and fasciculated on the outside, but smooth on the in- 
side, where it is covered with the synovial membrane. 
Accessory Ligaments are those which aid in sup- 
porting the capsular ligament. The internal lateral 
ligament of the temporo-maxillary articulation is 
such a structure. Accessory ligaments may pass over 
large portions of a single bone, or over many bones. 
Check Ligaments are those which limit the action 
of articular surfaces. The term is restricted by the 
older writers to a special ligament which limits the 
motion of the median atlo-axoid articulation. But 
in a more exact sense most of the ligaments about 
the joints of the limbs check undue motion of the 
articular surfaces. Thus the lateral ligaments of the 
joints between the phalanges check the lateral motion; 
the inferior calcaneo-scaphoid ligament checks the 
otherwise too free motion of the astragalus, etc. It 
follows that rupture of a check ligament will create 
dislocation. 
A Facet is a portion of articular surface which is 
distinguished from adjacent portions of the same sur- 
face by difference of curvature. Thus the occipital 
condyle has two facets, the patella seven, the head of 
the astragalus four, etc. 
Fibro-Cartilage is a tissue which has, as the name 
indicates, the properties of both fibrous tissue and 
cartilage. There are three varieties of fibro-cartilage 
-interosseous, interarticular, and circumferential. 
Interosseous fibro-cartilage is found between the bodies 
of the vertebrae, or between the pubic bones. It is 
firmer at the periphery than elsewhere, and may con- 
GENERAL CONSIDERATION'S. 
Joints or articulations are those portions of the 
body which serve to hold the bones in their natural 
relations to one another. They assist the bones in 
supporting the soft parts of the body, and in resist- 
ing shock. They thus resemble the skeleton, with 
which division of anatomy some writers include them. 
In their simplest forms they are composed of cap- 
sules, ligaments, synovial membranes, fibro-cartilage, 
and the cartilaginous coverings of the ends of the 
bones. It follows that a description of a joint must 
be in part a repetition of the account of such surfaces 
of the bones as are apposed within the joints. 
Ligaments are bundles of fibrous tissue that assist 
the joint surfaces in maintaining contact, and in limit- 
ing their ranges of motion. In all their functions they 
act in conjunction with muscles. They are flexible 
structures, and are attached to the bones they unite; 
they are often continuous with the periosteum, and 
are intimately incorporated with the origin and the 
insertion of muscles. 
In the study of the joints it is assumed, as above 
mentioned, that the cartilaginous surfaces are re- 
tained upon the ends of the bones, and that they, 
together with the accessory parts, are inspected in the 
living condition. 
The following are the definitions of terms used in 
the descriptions:- 
A Ligament is that structure which unites two 
separate bones. It may be composed of fibrous or 
elastic tissue. Prominent folds of synovial membrane 
are for convenience also termed ligaments. 
Ligaments exist either in the form of capsules or 
of separate bands or thongs. 
205 206 
THE JOINTS AND THE LIGAMENTS. 
tain in the centre, as in the last-named example, a 
synovial sac. 
Interarticular fibro-cartilage (meniscus) is found 
between articular surfaces, and divides the joint 
more or less perfectly into two compartments. 
The plate may extend entirely across the joint, as at 
the sterno-clavicular and temporo-maxillary articula- 
tions, in which forms it is apt to be thinned toward 
the centre; or it may be crescent-shaped, and fixed 
laterally to the capsule or ligaments of the joint, 
the remaining portion lying free in the joint, and 
covered with synovia on both sides. 
Circumferential fibro-cartilage is the name given to 
bands at the edges of sockets of bone, which serve to 
deepen the sockets. Such, for example, are the coty- 
loid ligament of the hip bone, and the glenoid liga- 
ment of the shoulder-blade. 
Synovia is the fluid secreted by a synovial mem- 
brane. It is a transparent, alkaline, albuminate fluid, 
of glairy consistence, yellowish color, and saltish 
taste. A synovial membrane is a delicate structure 
allied to serous membrane, and lines the joint cavity. 
It sends occasional pockets or culs-de-sac among the 
accessory ligaments or adjacent muscles. 
ON THE ACTION OF JOINTS. 
A correct conception .of the following subjects is 
demanded in studying joint-action: Atmospheric 
pressure, action of ligaments, presence of synovia, 
action of muscles, and the shapes of facets. 
Atmospheric Pressure.-The pressure of the atmo- 
sphere upon a joint forces the cartilages against one 
another, and the more yielding soft parts inward from 
all sides. The tags of synovial membrane occupied 
by fat are by the same pressure driven into spaces 
in the joint unoccupied by cartilages or capsule. 
When a joint is filled with fluid, as for example 
serum or pus, or, as in the course of experimentation 
on the subject, with water or air, the contact between 
the bones is broken. Atmospheric pressure, there- 
fore, as exerted upon a healthy joint, precludes the 
existence of a joint cavity in the proper sense of the 
term. 
Atmospheric pressure is best studied in joints hav- 
ing wide range of motion. In the knee, for example, 
when the condyles of the tibia are resting upon the 
posterior portions of the condyles of the femur (that 
is to say, the joint being in the position of extreme 
flexion), the anterior parts of the joint are separated 
from one another, and the integument on either side 
of the patellar ligament is to be seen depressed: the 
weight of the atmosphere, it is thought, has pushed 
the superficial parts in to occupy the otherwise gaping 
interval in the front of the joint. The brothers Weber 
found that the hip-joint remained intact as long as 
the normal relations to the atmospheric pressure 
were maintained. But the moment an opening was 
made through the bottom of the acetabulum the 
femoral and acetabular surfaces spontaneously sepa- 
rated. 
Action of Ligaments.-The ligaments assist in main- 
taining contact between joint surfaces, and in limiting 
the motion of articular surfaces. 
Presence of Synovia.-Synovia lubricates the inte- 
rior of the joint, and lessens friction. 
Action of Muscles.-No theory of joint action is com- 
plete without a knowledge of the action of those 
muscles that either cross over joints, or have their 
attachments at or about them. Appropriate muscular 
action determines the normal lines of pressure and 
resistance, and indicates the direction of motion of the 
various parts of the joint in changing from a flexed 
to an extended position. In joints of simple con- 
struction muscles may take the place of accessory 
ligaments, as, for example, in the shoulder, where it 
is shown that paralysis of such muscles causes the head 
of the humerus to fall away from the glenoid cavity 
of the scapula. It is probable that muscular action 
may serve as a compensating force in maintaining con- 
tact between the articular surfaces when the liga- 
ments are softened and relaxed by diseased action. 
The Shapes of Facets.-As the distance of the 
articular surfaces from one another in the healthy 
joint is invariable, and the condition above named 
nominally present, the degree of muscular power 
required to cause the curve-like motions of the joints 
is not so great as would at first sight be supposed. 
The shapes of the joint surfaces assist the ligament- 
ous or other checks in preventing too great latitude of 
motion. It is evident that the articular surface of 
the coronoid process of the ulna, for example, limits 
the degree of flexion of that bone upon the humerus, 
as the surface of the olecranon limits its extension. 
In like manner the entire ulno-humeral joint acts as 
a check to the radio-humeral rotatory motion, if 
indeed it does not convert it in the acts of flexion and 
extension from a rotatory to a ginglymoid joint. 
The slightly oblique path of movement of the humero- 
ulnar joint is checked by the direct path of move- 
ment of the radius on the humerus. In carnivorous 
animals, such as the badger, the motions of the 
temporo-maxillary joint are strictly confined by con- GENERAL CONSIDERATIONS. 
207 
spicuous processes, descending both in front and 
behind the temporal cavity to embrace the neck of 
the lower jaw so that the otherwise shallow socket 
is deepened. May not the significance of all forms of 
deep sockets depend upon the development of these 
retaining check processes? and may not the greater 
limitation of motion in the hip compared with that 
of the shoulder be due to the circumferential check 
surfaces of the former ? 
Sutura.1 Sutures are the common mode by which 
the bones of the cranium unite, and they are not seen in 
any other part of the adult skeleton. They are gener- 
ally described as being of four kinds, as follows : The 
harmonic suture. This is defined where two nearly 
smooth surfaces are opposed. The irregularity of 
many parts of the harmonic suture gives the clue to 
the significance of the remaining three. Examples 
are seen between the two horizontal plates of the 
superior maxillae, and between the corresponding 
plates of the palatal bones.-The squamosal suture. 
This variety is characterized by two bevelled surfaces 
which are opposed the one to the other. The outer 
overlaps the inner, and suggests an arrangement simi- 
lar to that existing between the scales of fishes. An 
example of the squamosal suture is seen in the human 
body in the union between the squamous portion of 
the temporal bone and the parietal bone.-The dentate 
suture. In this form tooth-like processes project from 
the opposed surfaces.-The serrate suture. This re- 
sembles the dentate, but is distinguished by the pro- 
cesses being more or less saw-like. The so-called 
limbose suture is a combination of the squamosal and 
serrate.-The interparietal suture is an instance of 
the dentate and the interfrontal of the serrate.-The 
sutures seen on the under surface of the calvarium 
are all harmonic, no matter what they may be upon 
the upper surface. 
Following upon external force an imperfectly defined 
motion is permitted between bones united by sutures 
that have not attained their full degree of development. 
The most important of these, according to P. Budin,2 
takes place in the foetal skull at the suture between 
the ascending portion of the occipital bone and the 
centres at the sides of the foramen magnum. The 
motion of the former upon the latter is described by 
this writer as hinge-like in character. When the 
ascending portion is bent forward on the suture, it is 
said to be flexed, and when backward, to be extended. 
Budin believes that one or the other of these move- 
ments, according to the presentation of the head, always 
takes place during parturition. 
Synchondrosis. Synchondrosis serves to unite 
the several centres in immature cartilage-bones. 
In the long bones it joins the epiphyses with the 
shaft, and the different centres of the irregular and 
tabular bones with one another. Good examples of 
synchondrosis are seen between the sphenoid and 
the occipital bones, at the costo-sternal articulation, 
in the body of the sternum, and among the different 
parts of the hyoid bone. The motion of synchon- 
drosis is exceedingly slight. 
Symphysis. The bone-surfaces in symphysis are 
flat and gently concave, as in the vertebrae, or 
irregularly sinuate, as in the pubic bones at the inter- 
pubic articulation. The surfaces are not free, but are 
held together by disks of flbro-cartilage, the short, 
tense fibres of which are so arranged that they are 
compactly interlaced toward the periphery, but are 
elastic and succulent toward the centre. In the inter- 
pubic articulation a synovial sac may be present. 
The bones uniting in a symphysis are further 
strengthened by accessory bands. 
Symphysis, as here defined, includes the amphi- 
arthrosis1 of the older writers. Meyer includes sym- 
physis under arthrodia,2 intending thereby to bring 
together all forms of broad and nearly flat movable 
articular surfaces. 
Examples of symphysis are seen between the bodies 
of the vertebrae (excluding the atlas and the axis), 
between the sacrum and the coccyx, between the 
pubic bones, and between the ilium and the sacrum. 
Both synchondrosis and symphysis require con- 
siderable exercise of force to disturb their equilibrium, 
and when the force ceases to act the joint surfaces 
resume the position of rest by reason of their own 
elasticity. Hence no forms of check or limiting 
mechanisms are met with in these joints. 
1 Amphiarthrosis also embraced the union between the different 
carpal and tarsal bones, especially where flat surfaces were con- 
nected by interosseous ligaments. 
2 The term "Arthrodia" is already in use to signify a group of 
articulations having a subordinate position in the one this writer 
would assign it. If it be held to be important to have a word to 
include all forms of movable joints, the word Lyenarthrosis is 
suggested as one that would be appropriate. This word implies 
that a joint therein placed is unfixed, as opposed to any given 
variety of Sutura and Synchondrosis which is fixed. 
1 For the classification of joints see the table on p. 208. 
2 De la Tete du Foetus au Point de Vue de 1'Obstetrique. Paris, 
1876, 72. 208 
THE JOINTS AND T IT E LIGAMENTS. 
Table of Joints.1 
SUTURA, 
includes the union of bones aris- 
ing from membrane. The bone 
surfaces are varied. 
Harmonia, when the surfaces are smooth or slightly irregular. 
Squamosa, when they overlap like the scales of a fish. 
Dentata, when the edge of the bone is armed with tooth-like processes. 
Serrata, when the processes named in the last group are saw-like. 
SYNCHONDROSIS, 
includes the union with carti- 
lage of bones arising from that 
tissue. The bone surfaces are 
flat or irregular. 
SYMPHYSIS, 
includes the union by means of 
fixed fibro-cartilage of bones 
which are without encrusting 
cartilages. The articular sur- 
faces of the bones are flat or 
nearly so. 
DIARTHROSIS, 
includes the union of bones that 
present to one another convex 
or concave surfaces of encrust- 
ing cartilages, and are covered 
with synovial membrane. 
Diarthrotic joints are called Arthrodial when the curvatures are faintly expressed. 
They are called Spherical when the curvatures are pronounced and their radii equal. 
They are called Cylindrical when f Hinge, with a trochlear or pulley-like surface. 
the curvatures are pronounced < Screw, with axis oblique to axis of bone. 
and their radii unequal. I Saddle, with opposed surfaces resembling those of a saddle, 
Conical, when the form is that of a cone. 
Composite, when the various features of diarthrosis are combined. 
1 The classification used by English writers (see Gray's Anatomy) 
is herewith presented for purposes of convenience in reference. 
Arthrodia. Gliding joint; articulations by 
plane surfaces, which glide upon each other. As 
in sterno- and acromio-clavicular articulations. 
Enarthrosis. Ball-and-socket joint; capable of 
motion in all directions. Articulations by a 
globular head received into a cup-like cavity. 
As in hip and shoulder-joints. 
Ginglymus. Hinge joint; motion limited to 
two directions, forwards and backwards. Arti- 
cular surfaces fitted together so as to permit of 
movement in one plane. As in the elbow, ankle, 
and knee. 
Diarthrosis rotatoria or Lateral Ginglymus. Arti- 
culation by a pivot process turning within a 
ring, or ring around a pivot. As in superior 
radio-ulnar articulation, and atlo-axoid joint. 
Dentata, having 
tooth-like processes. 
As in interparie- 
tal suture. 
Serrata, having 
serrated edges, like 
the teeth of a saw. 
As in in ter frontal 
suture. 
Limbosa, having 
bevelled margins, 
and dentated pro- 
cesses. 
As in fronto-pa- 
rietal suture. 
Sutura vera 
(true) arti- 
culate by 
indented 
borders. 
Diarthrosis. 
Movable joint. 
Sutura. 
Articula- 
tion by 
processes 
and in- 
denta- 
tions in- 
terlocked 
together. 
. Squamosa, formed 
by thin bevelled 
margins, overlap- 
ping each other. 
As in squamo- 
parietal suture. 
Harmonia, formed 
by the opposition of 
contiguous rough 
surfaces. 
As in intermaxil- 
lary suture. 
The above classification is based upon a mixture of form and 
function, and is arbitrary. The one proposed in the text is based 
upon form alone, and is in harmony with the facts of development. 
The main divisions of the old classification suggest three varie- 
ties of joint-the immovable, the mixed, and the movable. But 
joints either move or they do not; the language designed to de- 
scribe an intermediate, mixed joint is of necessity inexact. 
The varieties Schindylesis and Gomphosis are ignored in the 
classification of the text. The former is not a suture, since it 
occurs beween two bones of cartilaginous origin. It is a coap- 
tation, the result of an obliterated synchondrosis, a condition which 
does not demand a special name. The term "fissure" is inappro- 
priate for the sphenoidal aspect of the vomer. Of variable form, 
this surface is often narrowed, but never fissured.-The insertion 
of the teeth in sockets is in no sense articular. "Gomphosis" 
should be omitted from a classification of joints. 
The term Symphysis is employed in place of "Amphiarthrosis," 
which, as a term having systematic value, is discarded. The pre- 
sence of a synovial sac in some forms of symphysis is not sufficient 
ground on which to base a distinct variety. 
Diarthrosis and its divisions are essentially the same as in the 
classification adopted in the text. 
Synarthrosis 
or immovable 
joint. Surfaces 
separated by 
fibrous mem- 
brane, without 
any intervening 
synovial cavity, 
and immovably 
connected with 
each other. 
As in joints of 
cranium and 
face (except 
lower jaw). 
Sutura notha 
(false) arti- 
culate by 
rough sur- 
faces. 
Schindylesis. Articulation formed by the re- 
ception of a thin plate of one bone into a fissure 
of another. 
As in articulation of rostrum of sphenoid with 
vomer. 
Gomphosis. Articulation formed by the inser- 
tion of a conical process into a socket. 
The teeth. 
Amphiarthrosis. 
Mixed Articula- 
tion. 
1. bn riaces connected by h bro-car tilage, not 
separated by synovial membrane, and having 
limited motion. As in joints between bodies of 
vertebrae. 
2. Surfaces covered by fibro-cartilage ; lined 
by a partial synovial membrane. As in sacro- 
iliac and pubic symphyses. GENERAL CONSIDERATIONS. 
209 
Symphysis permits of a slight motion only between 
the bones united by its means. When a number of 
small bones, as the vertebrae, are thus joined, the mo- 
tion between any two is inconsiderable, but is natu- 
rally greater when the joints between all the bones 
act together. The motions of the vertebral column 
are by this means shown to be great; for the back- 
bone can be flexed, extended, and bent from side to 
side. At the pubis the union enables a slight out- 
ward stretching to occur in child-birth. The surfaces 
here may also glide slightly upon one another, 
especially if the synovial sac is developed. 
Diarthrosis. In diarthrosis the opposed bony 
surfaces are concavo-convex. The bones are free; 
the synovial membrane constant; the capsule loose, 
and ordinarily strengthened by muscles and acces- 
sory- ligaments. The joints of the limbs are exclu- 
sively of this character. They range from the sim- 
plest to the most complicated forms. So great is the 
motion permitted in diarthrosis, that all the surfaces 
of a given joint are never in contact with one another 
at the same time. In each particular position assumed, 
in passing from complete flexion to complete exten- 
sion, opposite facets, that are specially adapted to 
maintain such position, are brought in contact with 
each other. Such areas of contact change successively 
as the path of movement (by which term is meant 
the direction taken by a given articular surface in 
gliding over another) is followed. In the knee-joint, 
for example, it is found that in flexion the tibio- 
femoral facets near the posterior aspect of the joint 
are in contact, while the anterior surfaces are separated. 
In like manner, during extension the anterior surfaces 
are in contact, while the posterior are separated. 
The parts in contact may be said to be active, and 
those not in contact to be at rest. In addition to the 
above it may be seen that one of the bones composing 
the joint is fixed or inclines to be, while the other 
moves upon it. The fixed portion furnishes the 
axis of rotation. The plane on which the moving 
bone swings is the plane of motion, and moves in 
certain relations to the axis of rotation according 
to the special shapes of the joint surfaces. Thus 
in a rotary joint the plane of motion is called 
the plane of rotation, and in a hinge joint the plane 
of flexion or extension.--A pair of corresponding 
facets which are known to be active in certain posi- 
tions of the joint may be called after the kinds of 
activity they are engaged in. Thus one can speak of 
facets of flexion, or the facets of extension, etc. 
When the convexity is proximal, and the concavity 
distal, as in the astragalo-scaphoidal joint, the idea 
of the convexity resting within or upon the concavity 
is suggested; whereas, when the concavity is proxi- 
mal, and the convexity is distal, as in the shoulder- 
joint, the idea of the convexity falling away, or 
swinging within the concavity, is suggested. The 
former of these joints expresses a state of rest; the 
latter one of motion. 
The proper method of studying the motions of 
diarthrodial articulations is as follows :-• 
(1) The simplest form of an articulation is that in 
which the distal facet of one bone is in the same axis 
as the proximal facet of the opposed bone. Such 
joints may be termed primary joints, and the two cor- 
responding facets, primary facets. In the knee-joint 
it is found that the longitudinal axis answers to the 
outer femoral condyle, and hence the primary facet is 
to be found upon this surface; while the facet formed 
upon the inner femoral condyle is not primary, but 
secondary, and is a special feature added to the primary 
character of the joint.-The articular surfaces upon 
the sides of certain bones, as those between the tarsal 
and the metatarsal bones, and between the tibia and 
the fibula, are of significance different from that of 
either of the preceding; these may be termed the 
lateral or tertiary facets. 
A joint may be said to be at rest when the least 
amount of pressure exists between its opposed facets. 
It has been already noted above that extremes of 
extension and flexion fix a joint. The position of rest 
is ordinarily one between these two extremes, namely, 
the one termed semi-flexion. 
The supine position tends to rest the joints of the 
limbs, particularly those of the lower limb, since it 
removes the pressure of the weight of the body. 
If, however, the assumption that muscular action 
controls joint movements be correct, it follows that 
joints cannot be rested even in the supine position so 
long as their muscles are acting inordinately or in 
vicious directions. Hence the question of the rest of 
muscles enters into every problem of rest, and lies at 
the basis of all rational treatment of joint diseases. 
Any apparatus designed to keep the joint at rest must 
include all the muscles acting upon it. 
(2) The presence of a disk of fibro-cartilage between 
two cartilaginous articular surfaces tends to divide 
the joint, in a mechanical sense, into two chambers; 
in the knee there is a chamber between the femur 
and the disk on the one hand, and the disk and the 
tibia on the other. 
When it is remembered that these disks are, 210 
THE JOINTS AND THE LIGAMENTS. 
primarily, outgrowths from the capsule in the mo- 
tions of which they participate, and into which, as in 
the external inter-articular disk of the knee-joint, 
they project, it is seen that these disks are impor- 
tant factors in the movements of the articulations. 
When the living subject is standing erect, and the 
weight of the body is thrown chiefly upon the 
outer femoral condyle, the action of flexion is 
initiated by the change in position of the external 
disk, by means of which the tibia is moved slightly 
inward, and placed in a favorable position for gliding 
backward or inward along the inner femoral condyle. 
Flexion indicates the position of the limb in which 
the most acute angle possible exists between its seg- 
ments.1 Extension is the reverse of flexion; it is the 
position in which the angulation between the seg- 
ments is the least possible. If extension is carried 
beyond 180°, dorsal flexion begins. In flexion and 
extension, viewed as one movement, a form of rotation 
is seen, the distal end of the movable bone describing 
a wide arc of a circle about that of the fixed bone. 
Rotation is a movement of a bone upon itself in its 
longitudinal axis, as in the motion of the radius on 
the ulna. When rotation occurs with the limb de- 
scribing a circle it is called circumduction, and is the 
direct transmutation of one position of flexion into 
another, and the rotation of one or both bones in any 
position which the two bones may effect toward each 
other. 
Adduction is the traction of the part toward the 
median line. Abduction is the traction of the part 
away from the median line. 
When a movable articulation becomes immovable 
it is said to be fixed, and the passage from one to the 
other condition is controlled by muscular action. 
The arthrodial variety of diarthrosis; or 
the flat joints.-In this, the simplest form of diar- 
throsis, the surfaces are so slightly concavo-convex 
that they have been described by some writers as 
plane. 
In the assertion often made that the apposed 
surfaces of some bones are almost flat, we have no 
proper distinction drawn between the infinitely large 
varieties which can be created by slightly modifying 
nearly flat surfaces. It would be more accurate to say 
that such bones are opposed to one another by slight- 
ly concave and slightly convex surfaces, and that 
the motions between such surfaces do not glide so 
much as they rotate one upon the other, and are thus 
seen not to differ in kind from any other form of 
diarthrosis. In a joint of this kind the movement 
is necessarily slight. Examples of arthrodial joints 
are seen between the oblique processes of the verte- 
brae,1 and the joints between some of the bones of the 
carpus and the tarsus. 
The spherical variety of diarthrosis (ball- 
and-socket joint, or Enarthrodia). The convexity is 
marked in this form, and the concavity is smaller than 
it. Such a joint possesses many axes of rotation. It 
is with such that circumduction occurs. The hip and 
shoulder are examples of the spherical joint. It 
maintains on all sides an equal degree of motion.2 
The cylindrical variety of diarthrosis.- 
The convexity in this division is broad and elliptical, 
and suggests the form of the condyle. 
The cylindrical joints are divided into .the (a) hinge 
joint or ginglymus; (6) the screw joint; and (c) the 
saddle joint. 
(a) The Hinge Joint (ginglymus).-This is the best 
expression of a cylindroid joint. The axis of rotation 
is perpendicular to the axis of the moving bone, or, 
as in the case of the elbow, the axes of two bones, the 
radius and ulna, since both of these describe curva- 
tions round the axis of rotation. 
The paths of movement of the hinge joint are free 
within certain limits. These degrees of freedom are 
of necessity fixed by the direction of the greatest 
convexity. The co-operation of the surfaces is exact. 
(6) The Screw Joint (spiral joint).-In some facets 
of the more complex cylindrical joints the axis of 
the oblong convex surface falls obliquely to the axis 
of the concavity in which it plays. Such, for example, 
is the oblique facet on the inner condyle of the femur. 
(c) The Saddle Joint.-This is so called from the 
resemblance its surfaces bear to those of a saddle. 
Each articular surface is convex in one direction, and 
concave in the opposite. The saddle joint is peculiar 
in presenting its apposed concave portion in such 
fashion as to tend to embrace the convexity of the 
proximal one. The saddle joint can be flexed, ex- 
tended, abducted, and adducted, and, as a result of 
these varied movements, circumducted. It effects on 
the plan of the hinge joint the movements of a ball- 
1 Except the atlanto-axoid articulation, q. v. 
2 The terms of the above definition are doubtless not mathe- 
matically accurate. The term "spheroidal" is more exact than 
spherical. Of the two, the last-named is nevertheless preferred, 
since it is an equivalent of the term " ball-and-socket " in general 
use. 
1 For examination of tumors in position of flexion see Gross's 
System of Surgery, 5th ed. 1872, ii. 1065. GENERAL CONSIDERATIONS. 
211 
and-socket joint. The metacarpo-trapezoidal joint is 
the best example of-a saddle joint in the body. 
The conical variety of diarthrosis (pivot 
joint).-The convexity in this variety is in the form 
of a cone or disk, and clasped by a constricting liga- 
ment. Since in rotation the bone rolls upon its 
longitudinal axis, it is found that the axis of rotation 
of a conical joint agrees with that of the bone on 
whose periphery it occurs. Examples are seen in the 
superior radio-ulnar articulation, and in the atlanto- 
axoid articulation in part. 
The composite variety of diarthrosis.-When 
the contrasts between the various facets of a joint, 
are inconspicuous, it is said to be simple; when they 
are decided, it is said to be composite, since it com- 
bines in one the features of the spherical, the conical, 
or the cylindrical joint. A distinct motion is pre- 
sumed to correlate with each well-defined facet or 
curvature. 
When several kinds of curvature unite to produce 
a single motion, as, for example, when the rotary 
motion of the radius against the humerus unites with 
the hinge-motion of the ulna and humerus, or, as in the 
wrist, when the three convexities of the bones of the 
carpus correspond to the concavities of the surfaces 
yielded by the radius and the triangular ligament, the 
joint can be said to be aggregated (Meyer). 
General Remarks on the Development of the 
Joints.-The differences between the methods of 
articulation already described are based upon the 
manner after which the bones are developed. 
It will be remembered that the bones of the sides 
and vertex of the brain-case, and some of the bones 
of the face, develop from fibrous tissue (p. 97); such 
bones are connected by intervals of unossified mem- 
brane of varying width, and in time they unite by 
sutures which are so adapted as to permit of the 
increase in size of the brain, and the proper forma- 
tion of the chambers of the face, without impairing 
the strength of the skull. When the growth pf these 
structures is complete, the sutures, as a rule, disappear. 
This variety of union is called by the older writers 
Syndesmosis, the bones being joined by fibrous tissue, 
which in this sense is functionally the same as liga- 
ment, except that the tissue is continuous with the 
bed or plane of each bone, instead of being adjusted 
on the sides. 
In the event of a joint arising between two of a 
series of cartilage bones, there exists, as in the 
above variety, an unossified interval which is con- 
tinuous with the opposed ends of the bones. But 
this intervening tissue, instead of remaining undif- 
erentiated, is developed either into cartilage or fibro- 
cartilage. Should the development be arrested at 
this stage, and the mediating tissue be cartilage, the 
variety of union known as Synchondrosis occurs, an 
example of which is seen between the sphenoid and 
the occipital bones. 
If the mediating tissue be fibro-cartilage, Symphysis 
occurs, as is seen in the intervertebral and interpubic 
joints. 
Should the ends of the bones develop layers of car- 
tilage, and the intervening fibro-cartilage be parted 
therefrom by synovial membrane, and its own synovial 
surfaces be separated from one another, the form of 
joint arises such as is seen in the claviculosternal, 
the temporo-maxillary, and the carpo-ulnar joints. 
If the fibro-cartilage is rudimentary, and attached 
only to the capsular ligament, and the synovia-bearing 
surfaces are continuous with one another, the form of 
joint seen at the knee is recognized. 
If after the ends of the bones are furnished with 
cartilage, the fibro-cartilage is absorbed save a small 
band in the centre, the form of joint seen in the costo- 
vertebral and the ilio-femoral articulations arises. 
At least one of the crucial ligaments of the knee 
may be looked upon as the persistent central portion 
of the same primordial fibro-cartilaginous tissue 
which also remains on the sides of the joints in the 
former as in+erarticular disks. 
If the mediating cartilage and fibro-cartilage en- 
tirely disappear, the form of movable joint exempli- 
fied in the elbow or the shoulder is seen. 
The degree of possible influence exerted by muscle 
in effecting the evolution of the various forms of 
joints has as yet not been determined. It may be 
more than a coincidence that arrest of development 
at the stage of symphysis is seen in localities where 
comparatively slight motion occurs, as in the verte- 
bral column and pubis; while localities in which the 
true synovia-secreting joints are seen are moved 
freely by highly specialized and powerful muscles. 
Bernays1 does not credit muscle with any primal in- 
fluence, since he found in the knee-joint that the 
synovial membrane developed, and the essentials of 
the joint surfaces appeared before the joint became 
movable. It is at a later period only in his judg- 
ment that the influence of irregular muscular action 
is at all felt. J. Cunningham,2 however, in endeavor- 
1 Morph. Jahrbuch, 1878, Heft 3, p. 403. 
2 Journ. Anat, and Phys., 1878, p. 88 212 
THE JOINTS AND THE LIGAMENTS. 
ing to explain how an adventitious synchondrosis 
has eventually become developed into a diarthrodic 
joint, assumes that it has been accomplished by the 
traction of muscles. He found that among examples 
of detached epiphyseal centres of the vertebrae some 
were attached to the main bone by synchondrosis, 
and some by diarthrodia, and that the latter variety 
existed where there was the greatest indirect motion 
due to muscular action.1 
C. H. Hueter2 has written several suggestive papers 
on the peculiarities of the articular surfaces of the 
bones in the child and the adolescent. These papers 
have important bearings upon the subject of con- 
genital deformity, and indirectly upon the etiology of 
all obscure lesions of joint surfaces of limbs. By 
reason of the difficulty presented in an attempt to 
epitomize Hueter's elaborate statements, the reader is 
referred to the original. 
List of authorities consulted in preparing the above 
section. 
Au Introduction to Human Anatomy, etc., Wm. Turner, Prof, of 
Anat, in Univ, of Edinburgh, Edinburgh, 1867.-See also article 
"Anatomy," Encycl. Brit. 9th ed. 
Lehrbuch der Anatomic des Menschen, G. Hermann Meyer, 
Leipzig, 1873. 
Article "Articulations," Prof. Todd, Encycl. Anat, and Phys., 
Vol. I. 
Der Bau des Menschlichen Korpers, etc., Prof. Chas. Aeby, 
Leipzig, 1871. 
(1) The General Vertebral Ligaments. These are 
eight in number, as follows :- 
The Intervertebral Disks. 
The Anterior Vertebral Ligament. 
The Posterior Vertebral Ligament. 
The Interspinous Ligament. 
The Supraspinous Ligament. 
The Intertransverse Ligament. 
The Ligamenta Subflava. 
The Ligamentum Nuchae. 
The Intervertebral Disks or Cartilages (fig. 1, Plate 
XXXVI., fig. 2, Plate XXXVII.) connect the bodies 
of the vertebrae together from the axis downward. 
The general form of each disk answers to the shape of 
the bodies of the vertebrae between which it is placed. 
In addition to uniting the vertebrae, the disks aid 
in defining the intervertebral foramina, and, in the 
dorsal vertebrae, the facets which articulate with 
the ribs. The disks are narrowest between the third 
to the seventh dorsal vertebrae and between the 
bones of the coccyx. Each disk is composed of a 
laminated exterior and a pulpy interior. The for- 
mer portion makes up a little more than one-half 
of the entire disk. The pulpy portion is suscepti- 
ble of great change in form. Thus, when the bodies 
of a pair of adjoined vertebrae are divided transversely 
through the middle, it arises above the plane of the 
section. 
The peripheral fibres are composed of concentric 
layers of fibrous tissue and fibro-cartilage. These layers 
are arranged nearly vertically laterally, but are slightly 
curved as they approach the median line. Each layer 
is composed in such a way of oblique alternating fibres 
that successive arrangements of crossing fibres are 
seen. The pulp is placed a little nearer to the posterior 
than to the anterior border. Sometimes, according to 
Luschka, it sends a bud-like prolongation backward 
to the vertebral canal. Composed as it is of a loose 
stroma of fibrous tissue, holding in its meshes carti- 
lage cells of various sizes, the pulp is thought to rep- 
resent in the adult skeleton survivals of the chorda 
dorsalis, and to serve the purpose-under the great 
pressure to which it is subjected-of a ball or pivot 
held by stout peripheral fibres within the apposed 
axial surfaces of the bodies of the vertebrae. 
In the cervical and the lumbar region the disks 
are thicker in front than behind. In the cervical re- 
gion they about equal the thickness of the body of 
the vertebrae. In the dorsal region the disks are a 
little thicker behind than in front. The disk is the 
same height both before and behind at the junction 
THE JOINTS AND LIGAMENTS OF THE 
TRUNK. 
The Joints and Ligaments of the Trunk are ar- 
ranged as follows:-■ 
Those of the Vertebral Column. 
Those of the Lower Jaw. 
Those of the Thorax. 
The Joints and Ligaments of the Vertebral 
• Column. 
The Ligaments of the Vertebral Column are ar- 
ranged for convenience into- 
(1) The General Vertebral Ligaments. 
(2) The Special Ligaments of the Atlas, the Axis, 
and the Occiput. 
1 For an elaborate and experimental paper upon the capacities 
of the joints, the modifications of shapes, and position of the same 
as dependent upon distension, see Ed. Albert, in Stricker's Med. 
Jahrbiicher, 1873, p. 304. 
2 Virchow's Archiv, 1863. JOINTS AND LIGAMENTS OF TRUNK. 
213 
of the cervical and the dorsal and the dorsal and 
lumbar vertebrae. It is estimated that the length of 
the intervertebral disks equals about one-fourth of 
the entire length of the spine. 
Relations.-The disks in front are in relation with 
the anterior vertebral ligament, and by many muscles, 
such as the Rectus Capitis Anticus Major, the Longus 
Colli, the Diaphragm, and the Psoas Magnus, and 
behind with the posterior ligament, with which they 
more intimately unite than with the anterior. Upon 
the sides in the neck they are in connection with the 
Intertransversalis muscles; in the dorsal region with 
the heads of the ribs; in the lumbar region with the 
vessels and nerves which traverse the intervertebral 
foramina. 
Remarks.-According to W. Adams,1 ulceration of 
the intervertebral cartilages is a not unfrequent lesion 
in Pott's disease, and may exist independently of 
vertebral necrosis. From the examination of several 
cases of spinal disease in the early stages, and from 
the study of specimens in the London Museum, Mr. 
Adams concludes that in the majority of instances of 
destructive disease of the spine, the affection com- 
mences in ulceration of one or more of the interver- 
tebral fibro-cartilages, and generally in the central 
portions of the disk. The disease from first to last is 
sometimes limited to the intervertebral substance. 
The Anterior Vertebral Ligament (figs. 1 and 4, 
Plate XXXVI., fig. 1, Plate XXXVII.) extends along 
the front of the vertebral column from the axis to the 
second sacral vertebra. Straight above, it increases 
in breadth as it descends to a point opposite the 
dorsal vertebrae, where it forms, in addition to the cen- 
tral fasciculus, two lateral portions, which, however, 
are thin and present numerous openings for the 
passage of vessels. The ligament adheres anteriorly 
to the bones at such places, and throughout is firmly 
attached to the intervertebral disks. In minute struc- 
ture the ligament displays three distinct layers of 
fibres. The deepest are the shortest, and pass across 
each disk to the adjacent bodies of the vertebrae. The 
next pass from one bone to the third beyond, while 
the most superficial arise from one bone to be inserted 
in the third or fourth beyond. 
In the neck the anterior vertebral ligament appears 
as a shining line between the Longus Colli muscles. 
In front lie the pharynx and oesophagus. Within the 
thorax, the azygos vein, the thoracic duct, the descend- 
ing aorta, and the vena cava lie upon the ligament. 
Opposite the lumbar vertebrae the crura of the Dia- 
phragm and the Psoas muscle are attached to it. 
The Posterior Vertebral Ligament (fig. 1, Plate 
XXXVII.), thinner than the anterior, extends along 
the posterior surface of the bodies of the vertebrae, 
from the basilar process of the occipital bone to the 
lower lumbar vertebrae or even to the coccyx. It is 
broader above than below. Within the region of the 
neck it is spread evenly over the bodies of the verte- 
bral disks, and is thus of exceptional strength; 
but through the rest of its position it expands over 
the disks, but contracts upon the borders of the ver- 
tebrae opposite the pedicles, so that viewed as a whole 
it presents a festooned appearance. Above it is adhe- 
rent to the dura mater. Elsewhere it is distinct, 
and permits the vertebral veins to lie between it and 
the bone. Sappey states that it possesses more elastic 
tissue than does the anterior ligament. The minute 
arrangement of the fibres is essentially the same as 
in the anterior vertebral ligament. 
Remarks.-Both the anterior and the posterior 
vertebral ligaments are of great strength, and aid in 
limiting the motions of the vertebral column. Thus 
the anterior ligament acts as a check to extreme 
backward motion, as the posterior ligament pre- 
vents extreme forward motion. It is probable that 
after displacement of an intervertebral disk the liga- 
ments in question may prove to be capable of modi- 
fying the degree of dislocation of the contiguous 
vertebral bodies. Especially is this likely to be the 
case where the ligaments are of unusual strength. 
The Tnterspinous Ligaments (fig. 2, Plate XXXVII.) 
are thin membranous bands which unite the spines, 
from the root to near the apices, of all the vertebrae 
from the seventh cervical to the sacrum. They are 
the least developed in the dorsal region, but are thick 
and quadrangular in the lumbar. 
The Supraspinous Ligament extends between the 
summits of the spines of the vertebrae posteriorly to 
the interspinous ligaments with which it is continuous. 
In the neck it is thought to be represented by the 
ligamentum nuchae. The ligament is best developed 
in the lumbar region, where it assists in closing the 
spinal canal. It is connected by numerous points of 
contact with the Erector Spinae muscle. According 
to Quain, its posterior fibres pass downward from a 
given vertebra to a distance answering to the third or 
fourth vertebra below; those more deeply situated 
reach only from one to the next or the second below. 
1 Tr. Path. Soc. Lond., v. 1854, 243. 214 
THE JOINTS AND THE LIGAMENTS. 
The Intcrtransverse Ligaments are bands extending 
between the transverse and the oblique processes of the 
vertebrae. They are best seen in the lower dorsal and 
the lumbar vertebrae. They are rudimentary in the 
rest of the dorsal vertebrae, and rudimentary or absent 
in the cervical. region where their places are taken 
by the Intcrtransverse muscles. 
The Ligamcnta Subflava (fig. 2, Plate XXXVII.) 
are composed entirely of compact elastic tissue. They 
lie between the laminae and, in part, the oblique pro- 
cesses of the vertebrae from the axis to the sacrum, in 
such manner as to be seen to the best advantage from 
in front. Each ligament is attached a little in advance 
of the lower edge of the lamina above and to the pos- 
terior surface of the lamina below. It follows that 
the fibres composing it are not vertical, but are inclined 
a little downward and backward, and that the height of 
the ligament is slightly in excess of the space between 
the pair of laminae it unites. The ligaments slightly 
diminish in size from above downward, but are thicker 
in the loins than elsewhere. Each ligament is stoutest 
near the base of the lamina, but slightly increases in 
breadth toward the spine, where it forms a continuous 
band, pierced by several minute nerves. The fibres 
are more or less continuous with those of the inter- 
spinous ligaments. Between each ligament and the 
dura mater are interspersed a little cellular tissue and 
a few veins. 
The ligamenta subflava assist the erector muscles of 
the spine in maintaining the erect position of the spine, 
and in recovering this position from one of forced 
flexion. 
The Ligamentum Nuchae extends upwards from the 
spines of the cervical vertebrae, and is attached above 
to the occipital bone. It is composed of two parts: 
the superficial part extends from the spine of the sev- 
enth cervical vertebra to the occipital protuberance; and 
the deeper part is formed by the union of the succes- 
sive bands which arise from the remaining cervical 
spines, including the posterior tubercle of the atlas, and 
is attached to the occipital crest.-The ligamentum 
nuchse serves as an intermuscular septum between the 
right and the left sets of muscles of the back of the 
neck, and aids in a minor degree in supporting the 
head. It is the rudiment of the more pronounced 
elastic ligament of quadrupeds. Its upper portion 
may be felt in the living subject when the head is 
forcibly flexed upon the neck. According to Luschka, 
the ligamentum nuchae restricts abscesses of the back 
of the neck to their own side of the median line. 
(2) The Special Ligaments of the Atlas, the Axis, 
and the Occiput are nine in number, as follows:- 
The Transverse Ligament. 
The Posterior Atlanto-Axoid Ligament. 
The Capsular Ligaments. 
The Synovial Sacs. 
The Anterior Atlanto-Axoid Ligament. 
The Posterior Occipito-Atlantal Ligament. 
The Occipito-Axoid Ligament. 
The Anterior Occipito-Atlantal Ligament. 
The Odontoid or Check Ligament. 
The Transverse Ligament (figs. 2 and 3, Plate 
XXXVI.) extends across the central space inclosed by 
the atlas, and is attached by its extremities to the in- 
clined roughened surface on the inner side of each 
lateral mass. It divides the space into two parts: an 
anterior third for the reception of the odontoid process 
of the axis; and a posterior third for the spinal cord 
and membranes. The ligament is thick, and slightly 
concave forward aud convex backward, and from 
this circumstance has been termed by some authors 
the semilunar or semicircular ligament. It has been 
described by others as pitcher-shaped, the lip flange 
being in contact with the head of the odontoid 
process, while the lower vertical part embraces the 
EXPLANATION OF PLATE XXXVI. 
Fig. 1. Articulation of the bodies of the vertebrae. 
Fig. 2. Section of the occipital bone, the arias and the 
axis seen from behind, showing the articulation of the 
head with the atlas and the axis. 
Fig. 3. The atlas, showing the contents of the vertebral 
canal and joint between the odontoid process of the 
axis and the atlas. 
Fig. 4. A portion of the bodies of the vertebrae, with the 
vertebral ends of the ribs in position, showing the 
anterior vertebral and the costo-vertebral ligaments. 
Fig. 5. A dorsal vertebra and portion of adjacent ribs, 
showing the costo-sternal ligaments. PLATE XXXVl 
Fig 1 
Fig. 2 
F19-< 
Fi^.3 
Fig 5 
T. SincIiiT & Sonjath. JOINTS AND LIGAMENTS OF TRUNK. 
215 
neck of the process. The posterior surface of the 
odontoid process is covered with cartilage for action 
with the anterior surface of the ligament. Extending 
from the upper part of the ligament to the occipital 
bone is a small vertical bundle of fibres, and downward 
from the ligament to the body of the axis a second 
bundle. These make, together with the transverse 
ligament, a cross-like structure, which has received 
the name of the crucial ligament. 
Remarks.-According to Sappey, the odontoid pro- 
cess is held lightly within the grasp of the transverse 
ligament, so that if the other structures uniting the 
atlas and the axis are removed, the process can be 
inserted and withdrawn with ease. 
Luschka regards the transverse ligament as rep- 
resenting in part the unossified vertebra of the atlas. 
Should this view be accepted, the vertical ligaments 
above described may be considered as continuations 
of the posterior vertebral ligament. 
The Posterior Atlanto-Axoid Ligament (fig. 2, Plate 
XXXVI.) extends from the inferior border of the 
posterior arch of the atlas to the superior border and 
spine of the axis. The superficial portion is fibrous, 
and corresponds to the interspinous ligament of the 
lower vertebrae. The deeper portions contain elastic 
tissue, and are thought to be rudiments of the liga- 
menta subflava. 
The Capsular Ligaments (fig. 1, Plate XXXVII.) oc- 
cupy the interval between the occiput and the atlas, 
and between the atlas and the axis. They are simple 
environments of the articular surfaces with fibrous 
membrane, and do not differ from analogous joints else- 
where. They are least developed on the side toward 
the vertebral canal. The anterior occipito-atlantal 
articulation is strengthened by the lateral fibres of 
the posterior occipito-atlantal ligament. 
The Synovial Sacs. One of these exists between 
the odontoid process and the atlas, and another be- 
tween the posterior surface of the same process and 
the transverse ligament. 
The Anterior Atlanto-Axoid Ligament is a thin 
membranous structure extending between the lower 
border of the anterior arch of the atlas and the upper 
border of the body of the axis. 
The Posterior Occipito-Atlantal Ligament extends 
from the posterior and the lateral margins of the fora- 
men magnum to the upper border of the posterior 
arch of the atlas, where midway be'tween the occipital 
crest and the occipital condyle a tubercle of attach- 
ment is seen. Its deeper parts are continuous with 
the dura mater. The ligament extends between the 
posterior and the lateral margins of the foramen mag- 
num and the upper border of the posterior arch of the 
atlas. Its lateral portions are attached above to the 
tubercle which is seen about midway between the oc- 
cipital crest and the occipital condyle, and below to 
the posterior edge of the superior articular surface of 
the atlas. Toward the middle line the ligament closes 
in the vertebral canal. This pprtion is made tense 
when the head is flexed. 
The Occipito-Axoid Ligament (fig. 2, Plate XXXVI.) 
is a broad membranous structure extending between 
the anterior margin of the foramen magnum and the 
body of the axis. It is in close connection with the 
dura mater above, and is continuous with the poste- 
rior vertebral ligament below. Between it and the 
crucial ligament lies a small plexus of veins. A few 
of the fibres of the occipito-axoid ligament may serve 
to strengthen the transverse ligament of the atlas. 
The Anterior Occipito-Atlantal Ligament consists of 
a firm, strong membrane, extending from the anterior 
margin of the foramen magnum to the upper margin 
of the anterior arch of the atlas. It is strengthened 
in the middle by a distinct rounded band, which is 
attached to the anterior tubercle of the atlas. This is 
described by some writers as the anterior cervical 
ligament, and is supposed by them to be the beginning 
of the anterior vertebral ligament. The ligament is 
pierced by the vertebral artery. 
The Odontoid (Check, Lateral, Alar) Ligaments (fig. 
2, Plate XXXVI.) are short, stout, oblique bands, 
which arise from the tubercle to the inner side of the 
occipital condyles. They pass downward and inward, 
and are inserted into the sides of the odontoid process. 
Occasionally the fibres intercross in front of the head 
of the process. Attached to the tip of the odontoid 
process is an unimportant band of fibres, which unites 
the axis to the anterior margin of the foramen mag- 
num. It is designed chiefly to cover the space 
between the top of the atlas and the occipital bone. 
The closely united interlacing fibres constitute the 
transverse occipital ligament of Lauth. 
The Temporo-Maxillary Joint. 
The temporo-maxillary articulation (figs. 1, 2, 3, 
Plate XXXVII.) is composed of the upper surface of 216 
THE JOINTS AND THE LIGAMENTS. 
the condyloid process of the lower jaw, and that por- 
tion of the glenoid fossa in advance of the glenoid 
fissure, together with the articular eminence. 
The condyle is held in position by a capsular liga- 
ment which is weak in front and at the inner side, but 
stout behind and to the outer side. A portion of the 
oblique outer fibres extending from the root of the 
zygoma to the neck of the jaw has received the name 
of the external lateral ligament. 
Upon the inner side of the joint, but not related to 
it, is a loose, fascia-like band, extending from the 
spinous process of the sphenoid bone to the inner mar- 
gin of the posterior dental foramen. This is called 
the internal lateral ligament. Between it and the 
lower jaw lie the internal maxillary artery and inferior 
dental nerve. 
Within the joint are- 
The Interarticular Disk. 
The Synovial Sacs. 
The Interarticular Disk is of an elliptical form, more 
broad than long. It is depressed toward the centre 
below, for the reception of the head of the lower jaw. 
Above it is depressed in front for the articular emi- 
nence, and is elevated behind for the glenoid fossa. 
A Synovial Sac is situated one above and one below 
the disk. The former is the larger and looser of the two. 
Both sacs may communicate through an opening not 
unfrequently present in the centre of the disk. The 
motions of the temporo-maxillary articulation are a 
to-and-fro hinge-like motion, as seen in opening and 
shutting the mouth; and a lateral motion. In mod- 
erate antero-posterior movements the head lies within 
the glenoid fossa, but in pronounced depression of the 
lower jaw it glides forward upon the articular emi- 
nence. 
The Joints and Ligaments of the Thorax. 
Under the head of the joints and ligaments of the 
thorax are embraced- 
The Costo-Vertebral Joints and Ligaments. 
The Costo-Transverse Ligaments. 
The Intercostal Joints and Ligaments. 
The Costo-Sternal Joints and Ligaments. 
The Sternal Ligaments. 
The costo-vertebral joints and ligaments are 
of two kinds: those placed between the heads of the 
ribs and the bodies of the Vertebras-the Costo-Verte- 
brals proper; and those placed between the angles of 
the ribs and the transverse processes of the Verte- 
brae-the Costo-Transverse. 
The proper Costo-Vertebrals comprise- 
The Anterior Costo-Vertebral. 
The Capsular. 
The Interarticular. 
The Synovial Membrane. 
The Anterior Costo-Vertebral (stellate ligament) 
(figs. 4, 5, Plate XXXVI.) protects the head of the rib 
from in front. It is attached to the head of the rib, 
and passes in a radiate manner therefrom to the bodies 
of the adjacent vertebras and the intervertebral disk. 
The superior fascicle (proper anterior costal) is at- 
tached to the body of the vertebra above; the middle 
fascicle (middle costo-vertebral) to the intervertebral 
fibro-cartilage ; and the inferior fascicle (inferior costo- 
vertebral) to the vertebra below. 
The Capsular Ligament (fig. 5, Plate XXXVI.) is a 
delicate sac, inclosing the joint which unites the head 
of the rib and the vertebrae ; it is attached to the ante- 
rior ligament, where it is stouter than elsewhere. 
The Interarticular Ligament, absent in the first, 
eleventh, and twelfth ribs, extends from the ridge 
between the facets of the head of the rib to the inter- 
vertebral disk. While embraced within the capsule, 
the interarticular ligament is, properly speaking, not 
within the joint, since a Synovial Sac lies above it and 
another below it. 
The costo-transverse ligaments embrace- 
The Superior Costo-Transverse. 
The Middle Costo-Transverse. 
The Posterior Costo-Transverse. 
The Capsular. 
The Synovial Membrane. 
EXPLANATION OF PLATE XXXVII. 
Fig. 1. The basilar portion of the occipital bone-together 
with the atlas and the axis-showing the anterior ver- 
tebral ligament and two capsules opened. 
Fig. 2. A sagittal section of the vertebral column and pelvis, 
showing the various intervertebral and pelvic ligaments. 
Fig. 3. The sternum, the costal cartilages, and the sternal 
ends of the clavicles, showing the articular and liga- 
mentous attachments. PLATE XXXVII 
Figi 
F^. 2 
Fig. 8 
T Sinclair & S on, Lillie LIGAMENTS OF THE SUPERIOR EXTREMITY. 
217 
The Superior Costo-Transverse (anterior) (figs. 4, 
5, Plate XXXVI.) is attached below to the upper 
border of the neck of the rib, and passes upward 
and outward to be attached to the under surface of 
the transverse process next above. It is broader 
than the inferior, and is absent in the first and the 
twelfth ribs. 
The Inferior Costo-Transverse (middle interosseous) 
(figs. 4, 5, Plate XXXVI.) is attached to the lower 
border of the neck of the rib, and passes downward and 
slightly outward by short, stout fibres, to be attached 
to the anterior surface of the adjacent transverse 
process. It is rudimentary in the eleventh and 
twelfth ribs. 
The Posterior Costo-Transverse passes from the tip 
of the transverse process to the tuberosity behind the 
facet of the rib in connection with it. This ligament 
is wanting in the eleventh and twelfth ribs. 
The Capsular Ligaments unite the articular facets 
at the tuberosities of the first to the tenth ribs with 
the facets on the corresponding transverse processes. 
Synovial Sacs. Each joint, as above defined, is 
lined by a simple, delicate synovial membrane (fig. 5, 
Plate XXXVI). 
The intercostal joints and ligaments are as 
follows:- 
The Posterior Intercostals. 
The Anterior Intercostals. 
The Synovial Membranes. 
The Posterior Intercostal Ligaments (fig. 4, Plate 
XXXVI.) are thin bands, passing between the ribs a 
short distance in advance of the tuberosities. The 
Anterior Intercostal ligaments connect the costal 
cartilages from the sixth to the eighth. The Synovial 
membranes (fig. 3, Plate XXXVII.) are confined to 
the region last named. They are inconstant, simple 
in character, and variable in form. Sometimes the 
cartilages at points answering to the synovial sacs arc 
furnished with small facets. 
The costo-sternal joints and ligaments present 
the following structures :- 
The Anterior Costo-Sternal. 
The Posterior Costo-Sternal. 
The Capsular. 
The Synovial Membrane. 
The Anterior Costo-Sternal Ligament is a broad, 
membranous expansion, passing from the sternal ends 
of the costal cartilages of both sides, from the first to 
the seventh, to the anterior surface of the sternum, 
where the fibres freely interlace. The ligament does not 
support the costo-sternal articulations, but protects 
the sternum from in front. 
The Posterior Costo-Sternal Ligament is weaker than 
the anterior, and preserves to the posterior surface of 
the sternum the relations borne by the anterior costo- 
sternal ligament to the anterior surface. Special 
bands pass from the sixth and seventh costal cartilages 
to the ensiform cartilages. 
The Capsular Ligaments, usually described as en- 
closing the synovial membranes placed between the 
sternal ends of the costal cartilages and the sternum, 
are, properly speaking, portions of the anterior and 
posterior costo-sternal ligaments. Both the synovial 
membrane and the capsule are absent, as a rule, in 
the first costal cartilage. 
The Synovial Membranes at the second costo-sternal 
junction are two in number-one above, and the other 
beneath the ligamentous structure extending from a 
central ridge on the sternal end of the cartilage to 
the line of junction between the manubrium and the 
gladiolus. The remaining synovial cartilages inter- 
vene between the ends of the third to the seventh 
costal cartilages and the sides of the manubrium. 
Under the head of the sternal ligaments sys- 
tematic writers describe special bands of the anterior 
and the posterior costo-sternal ligaments that unite 
the manubrium and the gladiolus before the ossifi- 
cation of the sternum is complete. They do not 
require separate descriptions. 
THE LIGAMENTS OF THE SUPERIOR 
EXTREMITY. 
The Ligaments of the Superior Extremity are 
arranged in the following groups:- 
The Claviculo-Sternal Joint and Ligaments. 
The Joint and Ligaments of the Shoulder. 
The Elbow-Joint and Ligaments. 
The Ligaments of the Radius and Ulna. 
The Wrist-Joint and Ligaments. 
The Ligaments of the Hand. 
The Claviculo-Sternal Joints and Ligaments. 
The Claviculo-Sternal Joint is composed of the 
thoracic articular surfaces of the clavicle, the clavic- 
ular notch of the sternum, and the upper surface of 
the first rib. The ligaments holding the surfaces 
together are- 
The Anterior Sterno-Clavicular. 
The Posterior Sterno-Clavicular. 
The Interarticular Fibro Cartilage. 
The Synovial Membranes. 218 
THE JOINTS AND THE LIGAMENTS. 
The accessory ligaments are- 
The Interclavicular. 
The Costo-Clavicular. 
The Anterior Sterno-Clavicular Ligament is attached 
to the front and the upper part of the thoracic end of 
the clavicle, and passes obliquely downward and in- 
ward to the manubrium, and to a slight degree to the 
cartilage of the first rib. It increases in strength 
toward the interclavicular ligament with which it is 
continuous. Its upper fibres are in part contiguous 
to the clavicular fibres of the Sterno-Cleido-Mastoi- 
deus. 
The Posterior Sterno-Clavicular Ligament is at- 
tached to the posterior and the lower portion of the 
thoracic end of the clavicle, and passes in a somewhat 
radiating manner to the sternum and the cartilage of 
the first rib. 
The articular surfaces embraced by the above liga- 
ments yield unusual features. Instead of presenting 
concavo-convex facets, they are so shaped that the 
transverse (frontal) diameter of the clavicle is adapted 
to the antero-posterior (sagittal) diameter of the ster- 
num ; both surfaces are more or less saddle-shaped, 
and the clavicular surface is the larger.1 In order 
to make the surfaces in a degree coadaptive, the 
Interarticular Fibro-cartilagexs interposed. This disk 
is of a subrounded shape, wider and thicker above 
than below, while thin in the centre. It is held more 
intimately to the clavicle than to the thorax, and is 
placed obliquely from the upper border of the bone, 
downward and outward to the cartilage of the first 
rib. Its anterior surface is convex from within out- 
ward, and slightly concave from before backward. 
It answers only to the upper two-thirds of the cla- 
vicular surface;-the lower triangular facet which 
rests on the first rib is ordinarily not in contact with 
it. The disk exhibits many varieties. It becomes 
thinned with old age, and may be perforated, or even 
absent. 
The space between the disk and the sternum, and 
the space between it and the clavicle, are distinct; 
each is lined with a synovial membrane. The lateral 
cavity is much the more extensive of the two, is pro- 
longed a short distance beneath the clavicle, and, as 
a rule, admits from beneath a synovial fold that 
corresponds in position with the costal surface of the 
bone. This portion of the joint may, indeed, be 
entirely separate from the rest. 
The Interclavicular Ligament is a strong, coarsely- 
textured prismatic or flattened band extending across 
the supra-sternal notch between the sternal ends of 
the clavicles. At its ends the ligament is strengthened 
by slips which pass to the upper portion of the inter- 
articular disk, and to the margin of the manubrium. 
The Costo-Clavicular Ligament (rhomboid ligament) 
extends obliquely upward and backward from the 
upper margin of the first rib to the rough impression 
on the under surface of the clavicle near its thoracic 
end. It is strong, flat, and composed of oblique fibres. 
The ligament is covered by the Pectoralis Major mus- 
cle, and is stronger in the female than the male. The 
thin lateral edge is in relation with the median border 
of the Scalenus Anticus muscle.-It is subject to great 
variation. In rare instances Luschka has seen a pro- 
cess of bone take its place. 
Fracture of the clavicle to the median side of the 
costo-clavicular ligament does not1 prevent the outer 
fragment from passing forward. 
Movements.-The movements of the sterno-clavic- 
ular articulation are of two kinds-one which partakes 
of the ill-defined but wide range seen in symphy- 
sis, and another more limited, which is seen in 
diarthrosis. The former exists between the axial 
surface of the clavicle and the sternum. The latter 
1 The clavicular surface is concave above and in the centre, but 
convex below, while the sternal is elongate transversely, concave 
from within outward, and a little convex from before backward. 
1 R. W. Smith, Dublin Journ. Med. Sci. 1870, 8. 
EXPLANATION OF PLATE XXXVIII. 
Fig. 1. Sagittal section of the temporal and inferior max- 
illary bones, showing a similar section of the temporo- 
maxillary joint. 
Fig. 2. Portions of the same, showing the temporo-maxillary 
joint from without, as well as the ligamentous attach- 
ment between the skull and the hyoid bone. 
Fig. 3. The same from within, omitting the cranio-hyoid 
attachment. 
Fig. 4. The scapular ligaments and the claviculo-scapular 
attachment. 
Fig. 5. The same, viewed from in front, together with an 
anterior view of the shoulder-joint. 
Fig. 6. Sagittal section of the shoulder-joint. PLATE XXXVIII 
Fig.l 
Fig. 2 
Fig.3 
Fig.4 
Fig 5 
S' 
m 
"O 
V! 
Fig ; 6 
T. Sinclair & 
Son Ljih. LIGAMENTS OF THE SHOULDER. 
219 
exists between the inferior portion of the thoracic end 
and the first rib. The symphyseal motion is capable 
of assuming, under some conditions, a great degree of 
latitude, owing to the mobility of the interarticular 
disk. It would be brought greatly into play in the 
act of swimming. The diarthrodial movements are 
determined by the actions of the muscles that depress 
and draw forward or backward the clavicle, as follow- 
ing the forced action of the Pectoralis Major, the 
Latissimus Dorsi, etc. The movements of symphy- 
sis are in a measure checked by the interarticular 
ligament, while those of diarthrosis are checked by 
the costo-clavicular ligament. 
The claviculo-sternal articulations are of great 
strength, since upon the maintenance of the clavicle 
against the sternum depend the movements of the 
humerus. Luxation of this joint is infrequently seen. 
The bone may also be displaced upward and, more 
rarely, backward. 
where it is continuous with a thin layer of connective 
tissue underlying the Deltoid muscle. It is lost in the 
connective tissue over the infra-spinous fossa.-Ac- 
cording to Henle, the posterior margin of this ligament 
passes over the supra-spinous fossa. Beneath, the 
ligament is loosely held to the tendon of the Supra- 
spinatus muscle and the capsule of the shoulder-joint. 
The upper surface, from which it is separated by a 
bursa, is covered by the Deltoid muscle. The outline 
of the ligament can be felt under the skin. 
The acromio-coracoid ligament and the coracoid 
process and the acromion form a wide though low 
vault, against which the head of the humerus and 
the upper portion of the great tuberosity are held 
during the contraction of the Supra-spinatus muscle 
and the consequent elevation of the arm. 
The Glenoid Ligament is a triangular rim of fibro- 
cartilage which surrounds the edges of the glenoid 
fossa. It is usually less thick below than above, 
where it is in intimate association with the tendon of 
the Biceps muscle. It is more prominent on the 
median as compared with the lateral edge, is of a yel- 
low color, and composed of concentrically arranged 
fibres. 
THE SCAPULAR ATTACHMENTS OF THE CLAVICLE. 
These are two in number as follows:- 
The Acromio-Clavicular Joint. 
The Coraco-Clavicular Ligament. 
The Acromio-Clavicular Joint. 
The Acromio-Clavicular Joint consists of a diar- 
throdial joint situated between the clavicle and the 
acromion, and is composed of two obliquely placed 
opposed facets, the upper of which is derived from 
the clavicle. Both surfaces are covered with a thin 
layer of fibro-cartilage. It is subject to much vari- 
ation in form, and is best developed in muscular 
individuals. 
It presents for examination the following struc- 
tures :- 
The Superior Acromio-Clavicular Ligament. 
The Inferior Acromio-Clavicular Ligament. 
The Interarticular Fibro-Cartilage. 
The Synovial Membrane. 
The Superior Acromio-Clavicular Ligament consists 
of straight fibres extending from the lateral end of 
the clavicle to the median side of the acromion. 
The Inferior Acromio-Clavicular Ligament extends 
between corresponding points with the superior, and 
does not require separate description. Some writers 
The Joint and Ligaments of the Shoulder. 
The region of the shoulder includes the scapular 
end of the clavicle, the scapula, and the head, neck, 
and tuberosities of the humerus, together with the 
soft parts covering the above structures. 
The ligaments and the joint structures are as fol- 
lows :- 
The Ligaments of the Scapula. 
The Scapular attachments of the Clavicle. 
The Shoulder-Joint. 
THE LIGAMENTS OF THE SCAPULA. 
The ligaments of the scapula are- 
The Transverse. 
The Acromio-Coracoid. 
The Glenoid. 
The Transverse Ligament is a delicate band of 
fibrous tissue, extending across the scapular notch. 
It arises from the base of the coracoid process, and it 
is inserted into the external edge of the upper border 
of the scapula. It consists, as a rule, of two fasciculi, 
one pertaining to the dorsal, the other to the ventral 
aspect of the notch.-Usually transverse, the fibres of 
this ligament may be oblique, and nearly parallel to 
the axillary border of the scapula, and in part con- 
tinuous with the fibres of the conoid portion of the 
coraco-clavicular ligament. 
The Acromio-Coracoid Ligament extends as a broad, 
somewhat triangular ligament between the lateral 
border of the coracoid process and the tip of the acro- 
mion. It is free and thick behind, but tapers in front 220 
THE JOINTS AND THE LIGAMENTS. 
describe the ligaments of the acromio-clavicular joint 
as constituting a true capsule. Since the facet occu- 
pies the posterior part of the scapular portion of the 
clavicle only, it follows that the ligamentous tissue in 
advance of the facet is entirely distinct from the 
joint.-The capsule is composed of a number of 
straight fibres, embracing the facets, and extending 
from the lateral end of the clavicle to the median side 
of the acromion. It is much thicker above than below. 
The Interarticular Fibro-Cartilage is rudimental. 
The capsule sends the disk inward from its under 
surface. It is rarely sufficiently large to separate 
entirely the joint surfaces, and may be absent. 
The Synovial Membrane resembles the membrane 
found in other joints. When the interarticular fibro- 
cartilage is complete, two sacs are formed. 
Dislocation of the scapular end of the clavicle is 
exceedingly difficult to reduce. 
The Coraco- Clavicular Ligament. 
The Coraco-Clavicular Ligament extends from the 
clavicle at and near the conoid tubercle to the cora- 
coid process. It is composed of two portions-the 
conoid and the trapezoid, which are often spoken of 
as distinct ligaments. The two portions are more or 
less continuous on the coracoid process, as they con- 
verge from the clavicular attachments. The conoid 
portion (conoid ligament) is nearly vertical, and is 
placed somewhat behind and to the median side of 
the trapezoid. It is more or less triangular in form, 
and extends between the conoid tubercle and the 
posterior border of the scapular end of the clavicle 
downward, to be attached to the median side of the 
base of the coracoid process directly in front of the 
scapular notch. It oftentimes receives a small fascicle 
from the sheath of the Subclavius muscle. The 
trapezoid portion (trapezoid ligament) extends ob- 
liquely from the clavicle downward and inward. It 
is placed somewhat in front and to the lateral side of 
the conoid portion, and is attached above to the clavicle 
from the oblique line on the under surface of the 
scapular end of the clavicle, and below to the rough 
surface of the median border of the base of the cora- 
coid process. A bursa is often found between the 
two ligaments. The subclavicular groove extends a 
short distance between them. 
Movements.-In the acromio-clavicular joint the 
clavicular facet and the inter-articular disk are rela- 
tively fixed ; while the scapular facet is circumducted, 
and responds to all the motions of the scapula. The 
coraco-clavicular ligament acts as a check to rotation 
of the scapula, and indirectly relieves the joint from 
strain. The acromio-coracoid ligament also relieves it, 
as in the acts of creeping and in pushing downward 
THE SHOULDER JOINT. 
The shoulder-joint (scapulo-humeral joint) repre- 
sents the contact of the head of the bone against the 
glenoid cavity of the scapula. Both the surfaces are 
covered with cartilage. That on the humerus is 
thickest in the middle, and thinnest at the sides; 
that of the glenoid cavity is thinnest in the middle, 
and thickest at the sides. 
The ligaments of the shoulder-joint arc- 
The Capsular Ligament. 
The Coraco-IIu moral Ligament. 
The Synovial Membrane. 
The Capsular Ligament is a loose capsule of fibrous 
tissue attached to the neck of the scapula just beyond 
the brim of the glenoid cavity above, and to the neck 
of the humerus below. It is notably strengthened 
externally by a band arising from the base of the 
coracoid process, and directed toward the greater 
tuberosity of the humerus, known under the name or 
the coraco-humeral ligament, and in a less degree by 
the tendons of the Supra-spinatus, the Infra-spinatus, 
and the Subscapular is muscles. The two muscles 
last named are remarkable for the intimate manner in 
which the fibres of the capsule are associated with 
them. The capsule is weakened at the point of union, 
and may be defective, as in the instance where the 
tendon of the Subscapularis and that of the Infra- 
spinatus lie in contact with it.-The ligament forms a 
loose vertical fold at the inner side of the neck of the 
humerus when the arm is in repose. This fold is, 
however, obliterated when the arm is elevated.-The 
capsule is sufficiently capacious to hold a body much 
larger than that of the head of the humerus, and 
requires the sustained action of the muscles about the 
joint to keep the head of the bone in position. It 
is supported within by the long head of the Biceps 
muscle, which passes over the head of the humerus, and 
which serves to give it support by the pressure exerted 
from below upward. It is further strengthened from 
without by the position of the coracoid process, the 
acromion, and the coraco-acromial ligament. 
The Synovial Membrane of the shoulder-joint 
sends short prolongations along the course of the 
Infra-spinatus and the Subscapularis muscles and the 
defective places in the capsule. A third cul-de-sac 
passes along the entire length of the bicipital groove 
cf the humerus, which is inclosed bya transverse fibrous LIGAMENTS OF THE ELBOW. 
221 
band above, and by the fibrous extension of the tendons 
of the Latissimus Dorsi and the Teres Major muscle 
at the floor and sides. A delicate fold of the synovial 
membrane assists the long head of the Biceps mus- 
cle in retaining its position in the bicipital groove. 
Humphry says that the head of the humerus in 
dislocation of the shoulder is sometimes received 
within the bulging cul-de-sac of the synovial mem- 
brane under the Subscapularis. 
The Arteries of the joint are branches of the ante- 
rior and the posterior circumflex and suprascapular. 
The Nerves are branches of the circumflex and the 
suprascapular. 
Remarks.-The movements of the shoulder-joint 
are so combined with the functions of the shoulder 
muscle that it is impossible to disassociate them. The 
chief agency, here as in other diarthrodia, in the main- 
tenance of contact between the humerus and the scap- 
ula, is atmospheric pressure. Marked rotation of the 
humerus outward in the subject will cause separation of 
the surfaces, when the head of the humerus will fall 
away from the scapula. Rotation of the arm inward 
restores the normal contact between the two. This 
observation, made on the authority of Henke, may be 
received with a single qualifying fact, that the de- 
scription is known to be true of the dead subject only.- 
It is more than probable, even if the original non- 
elastic muscles about the joint interfere with their 
physiological uses in maintaining contact, that inward 
rotation is in many features distinct from outward 
rotation. The outer (lateral) half of the head of the 
humerus when covered with cartilage differs from the 
median. The former is the more convex side of the 
surface, and ends abruptly at the anatomical neck; 
the latter, in addition to being flatter, ends impercep- 
tibly at the neck, and is continuous at its borders 
with the capsule. The line separating these two 
surfaces is well defined by the coraco-humeral liga- 
ment, which answers to the greatest length of the head 
of the humerus obliquely downward and outward. 
On the posterior surface of the joint the scapular head 
of the Triceps lies nearly in a similar line. The 
muscles strengthening the joint and assisting in main- 
taining contact are, apart from the scapular muscles 
proper, the Deltoid, the Biceps, the Coraco-brachialis, 
the Triceps, and upper part of the Serratus Magnus. 
Unaided contraction of the Deltoid tilts the head of 
the humerus downward from the glenoid cavity-in 
wrhich action the Serratus Magnus and the Pectoralis 
Major assist.1 
The joint is strengthened in such movements by 
the Coraco-Brachialis, and the scapular head of the 
Triceps. 
For the mechanism between the humerus and the 
acromion, see W. Ruge.1 
The Costo-scapular Joint. Under this head Lusch- 
ka2 has described a bursa-like joint between the 
scapula and the third and fourth ribs of the left side. 
R. Hesse3 gives a case in illustration of the presence 
of this joint in a man aged twenty-three, who com- 
plained of a grating sensation in moving the left arm, 
and of slight pain at the junction of the second and 
third ribs with the sternum. Noisy crepitation was 
readily observed upon motion of the scapula. 
Remarks.-The coraco-clavicular ligament is of 
enormous strength. It limits rotation of the scapula 
forward and inward, and is the chief agency by which 
elevation of the scapula is effected by muscles inserted 
into the clavicle, namely, the Sterno-Cleido Mastoid 
and the Trapezius. 
The Elbow-joint and Ligaments. 
The parts entering into the elbow-joint are the 
trochlear surface and the radial head of the humerus, 
the greater and lesser sigmoid cavities of the ulna, 
and the head and the neck of the radius. These parts 
are inclosed in a common capsular ligament which is 
notably thickened at the sides ; but it is thin both in 
front and behind, and is intimately attached to the 
annular ligament holding the head of the radius in 
position. 
The parts to be studied, therefore, at the elbow- 
joint are- 
The Capsular Ligament. 
The Internal Lateral Ligament. 
The External Lateral Ligament. 
The Orbicular Ligament. 
The Synovial Membrane. 
The Capsular Ligament is very loose, though on 
the w'hole thin and of varying thickness. It extends 
in front from above the coronoid fossa to the coronoid 
process and' the annular ligament, and behind from 
above the olecranon fossa to the olecranon. Anteri- 
orly it is stronger at the middle than at the sides, and 
is covered by the Brachialis-Anticus muscle. Behind 
it is relatively strong above the tip of the olecranon, 
but very weak and bursa-like at the side, where it is 
composed of transverse fibres extending from the ole- 
> Zeit. fur Rat. Med., 1859, 258. 
2 Prager Vierteljahrschr , cvii. 1870. 
3 N. Y. Med. Journ., 1871, 730. 
1 Duchenne, Physiologie des Mouvements. 222 
THE JOINTS AND THE LIGAMENTS. 
cranon to the lateral margins of the humerus. The 
interstices between the ulna and radius are filled 
with fat. 
The Internal Lateral Ligament is composed of two 
fasciculi of diverging fibres,-an anterior and a 
posterior. The anterior fasciculus, the stronger and 
more superficial of the two, extends between the ante- 
rior surface of the epitrochlea and the inner margin 
of the coronoid process; it serves to limit extension. 
The posterior fasciculus, thin and radiated, extends 
from the posterior surface of the epitrochlea to the 
side of the olecranon, and serves to limit flexion. 
It is directly continuous with the capsule poste- 
riorly. Between these two fasciculi is a minute 
foramen answering to the notch at the inner end of 
the transverse groove, which is filled with a pellet of 
fat. The internal lateral ligament is covered by the 
common flexor mass. The ulnar nerve is, in a meas- 
ure, protected by an imperfect fibrous canal, which is 
covered by the ulnar fibres of origin of the Flexor 
Carpi Ulnaris muscle. 
The External Lateral Ligament is an imperfectly 
defined thickened band of the capsule, extending 
from the epicondyle, and spread out over the orbicular 
ligament, which it holds in position. It is shorter 
than the internal. Posteriorly a number of its fibres 
are attached to the ulna. The external lateral liga- 
ment is covered by the origin of the common exten- 
sor mass, and yields points of origin for the Supinator 
Brevis muscle. 
The Orbicular Ligament (annular, coronary ligament) 
is a strong ring-like band attached to the anterior and 
the posterior edges of the lesser sigmoid cavity. It 
is thicker behind than in front, and thinner above 
than below, where it ends at the neck of the radius. 
It describes four-fifths of a circle, and encompasses 
the vertical surface of the head of the radius. It is 
sustained by the fibres of the external lateral liga- 
ment and a portion of the anterior division of the 
capsule. At a point where these structures are di- 
vided, the annular ligament sinks to the position of 
the neck of the radius. According to Cruveilhier, the 
ligament is easily ruptured in front. In luxations it 
is not the external lateral, but rather the anterior por- 
tion of the orbicular ligament that is ruptured. 
The Synovial Membrane lines the ulno-humeral as 
well as the radio-humeral surfaces. Morbid growths 
developed within the plicae of this membrane may 
resemble movable cartilages. Luschka mentions a case 
in which a body of this kind placed in the olecranon 
fossa prevented full extension of the forearm.-The 
ulnar nerve lies so near the capsule that its section 
at this point cannot be attempted without endanger- 
ing the integrity of the joint. 
The Arteries are derived above from the com- 
municating branch between the superior and the 
inferior profunda and the anastomotic branches of the 
brachial, and below from the recurrent branches of 
the radial and the ulnar arteries. 
The Nerves of the elbow-joint are received pos- 
teriorly from a branch of the ulnar nerve, and ante- 
riorly from a branch of the radial. 
Movements.-The elbow-joint embraces two lines 
of movement: a movement of flexion and extension 
taking place between the trochlea of the humerus 
and the ulna; and a movement of rotation taking 
place between the radial head of the humerus, the 
orbicular ligament, and the head of the radius. The 
last-named portion of the joint enters into flexion and 
extension with that of the trochleo-ulnar movements. 
Flexion is checked by the coronoid process lying 
within the coronoid depression of the humerus.- 
Pronation and supination may be demonstrated in 
extreme flexion, when the motion occurs between 
the raised rim of the radial proximal surface and the 
depression above the radial head of the humerus.- 
Extension is checked by the olecranon lying within 
the olecranon fossa of the humerus. It is limited by 
about 180°.-Inward rotation is checked by the late- 
ral border of the vertical surface of the radial head 
impinging against the anterior portion of the orbicu- 
lar ligament.-Outward rotation is checked by the 
oblique ligament and by the median border of the 
radial head impinging against the orbicular liga- 
ment. 
The lateral ligaments are of great importance in 
maintaining the integrity of all parts of the elbow- 
joint. The joint is destroyed, should one of them be 
divided. 
The bones of the forearm do not coincide with the 
axis of the arm, either in flexion or in extension. In 
flexion they incline inward, and in extension out- 
ward. The latter inclination is most pronounced in 
supination. In applying an extending force to the 
forearm with a view of influencing the shoulder, it 
is recommended to pronate the hand. In this posi- 
tion the inclination of the forearm outward is measur- 
ably removed.1 
The movements of flexion and extension are per- 
formed on paths that are held by H. Meyer2 to be 
portions of a screw-like or spiral figure. 
' Richet, Anat. Medico-Chirurg., 897. 
2 Arch. f. Anat. Physiol, und Wissensch. Med., 1866. LIGAMENTS OF THE WRIST. 
223 
The several parts of the joint, therefore, are- 
The Anterior Radio-Ulnar Ligament. 
The Posterior Radio-Ulnar Ligament. 
The Fibro-Cartilage. 
The Synovial Membrane. 
The Anterior and the Posterior Radio-Ulnar Liga- 
ments (figs. 2, 4, and 5, Plate XXXIX.) are straight 
and narrow bands extending on either side of the 
radio-ulnar articulation. 
The Fibro-Cartilage is of a triangular form, placed 
transversely to the axis of the forearm. It is thick, 
and attached by its base to a ridge at the carpal side 
of the sigmoid of the radius; and by its small 
extremity to the notch between the head of the radius 
and the styloid process. It is thin at the sides and 
centre, where, indeed, it may be perforated, but thick 
at the apex and the circumference. The apex is a stout 
ligamentous structure by means of which the carti- 
lage is attached to the ulna. It is concave on both 
sides-above for the head of the ulna, and below for 
the cuneiform bone. 
The Synovial Membrane between the radius and the 
ulna is continuous with that between the fibro-cartilage 
and the head of the ulna. It is known as the mem- 
brana sacciformis, and is remarkable for containing a 
relatively large amount of synovial fluid. 
The movements of pronation and supination do 
not affect the ulna when the elbow-joint is extended, 
but induce a slight rotatory motion, which is best 
marked at the distal end when the elbow is semi-flexed. 
The Wrist-Joint. 
The wrist-joint (radio-carpal) (figs. 2, 4, and 5, Plate 
XXXIX.) is formed by the distal end of the radius, 
together with the triangular fibro-cartilage articu- 
lating with the proximal surface of the first row of 
carpal bones. - The proximal factor of the wrist- 
joint is composed of the radius, which forms its outer 
two-thirds, and of the fibro-cartilage, which forms its 
inner third. The general surface is concave in both 
directions, and marked by three impressions: the 
outer for the scaphoid bone, the middle for the semi- 
lunar bone, and the inner for the cuneiform bone. 
The sides of the concavity are deepened by the sty- 
loid processes.-The distal factor is convex in both 
directions, with an inclination toward the dorsal sur- 
face. The joint embraces- 
The Capsular Ligament. 
The Internal Lateral Ligament. 
The External Lateral Ligament. 
The Ligaments of the Radius and the Ulna. 
The movements of pronation and supination take 
place between the radius and the hand as one factor, 
and the humerus and the ulna as the other. 
The joints interested in the movements are- 
The IIumero-Radial. 
The Superior Radio-Ulnar. 
The Inferior Radio-Ulnar. 
The Humero-Radial Joint (figs. 1 and 3, Plate 
XXXIX.) is a part of the elbow-joint, and has been 
already described. 
The Superior Radio-Ulnar Joint exists between the 
convex circumferential vertical border of the head of 
the radius and the concave lesser sigmoid cavity of 
the ulna. The elbow-joint in great part defines it. It 
is strengthened by the orbicular and the oblique 
ligaments. 
The Oblique Ligament is a stout band passing 
obliquely downward and outward from the region of 
the base of the coronoid process (tubercle) of the ulna 
to the radius a little distance below the tuberosity. 
It acts as a check to supination. 
THE INTEROSSEOUS MEMBRANE. 
The membrane stretching across the space between 
the radius and the ulna is called the interosseous 
membrane. It is attached by roughened borders, 
which are specially well marked at the upper portion. 
Aponeurotic in structure, the membrane is composed 
of thin fibres directed obliquely downward and in- 
ward, while its posterior surface is strengthened by 
fibres passing in the opposite direction. It imperfectly 
occupies the interosseous space, since it begins about 
an inch below the tubercle of the radius, and termi- 
nates a short distance above the wrist-joint. It is 
perforated at several points for the passage of small 
bloodvessels, and toward the lower border by a larger 
opening for the posterior interosseous artery. 
The interosseous membrane assists the oblique 
ligament in checking supination. It also acts as an 
intermuscular septum between the muscles on the 
anterior and the posterior portion of the forearm. 
THE INFERIOR RADIO-ULNAR JOINT. 
The head of the ulna is held in the sigmoid cavity 
of the radius by the anterior and the posterior radio- 
ulnar ligaments. Between the free distal end of the 
ulna and the cuneiform bone a plate of fibro-cartilage 
is inserted. 224 
THE JOINTS AND THE LIGAMENTS. 
The Capsular Ligament. The anterior portion of 
the capsular ligament is shorter toward the radial 
side, and stronger than the posterior. It extends 
from the lower border of the forearm to the first 
row of carpal bones - thence a slip is continued to 
the os magnum. - The posterior portion (rhomboid 
ligament) descends obliquely downward and outward 
to the first row of bones, the fibres notably converg- 
ing toward the cuneiform bone. 
The Internal Lateral Ligament passes as a firm 
cylindrical cord from the spinous process of the ulna 
to the cuneiform bone, at the same time sending 
fibres to the pisiform bone and the anterior annular 
ligament. It is partially covered by the Extensor 
Carpi UI naris muscle. 
The External Lateral Ligament, stouter though less 
defined than the preceding, passes from the styloid 
process of the radius to the scaphoid bone, where it 
effects a broad attachment. It contributes to the 
composition of the anterior annular ligament, and 
thence is continued to the trapezium. Its lateral side 
is in relation with the Extensor Ossi Metacarpi 
Pollicis muscle. 
The Synovial Membrane is loose behind. At times 
the cavity is continuous with the pisiform articula- 
tion, and at others, through the absence of one of the 
interosseus ligaments of the first row, with the inter- 
carpal synovial sac. 
The wrist-joint is in a line with the apex of the 
styloid process of the ulna. 
The Joints and the Ligaments of the Hand. 
These comprise- 
The Joints and Ligaments of the Carpus. 
Those of the Carpo-Metacarpal Joint. 
Those of the Inter-Metacarpal Joints. 
Those of the Metacarpo-Phalangeal Joints. 
Those of the Inter-Phalangeal Joints. 
The Joints and Ligaments of the Carpus include 
the structures uniting the bones in each row, and 
those that unite the two carpal rows. 
The bones of the first row of the carpus are united 
on the dorsal surface by a ligament placed between 
the scaphoid and the semilunar bones, by one between 
the semilunar and the cuneiform, and by a third-an 
interosseous ligament-placed near the dorsal surface, 
and uniting the last-named bones. 
On the palmar surface the bones are united by 
three bands, stretching from the scaphoid to the 
semilunar bones, and from the semilunar to the 
cuneiform. 
The bones of the second row are united by similar 
bands to the foregoing, situated on the dorsal and 
the palmar surfaces. These pass between the os 
magnum and its associated bones, the trapezoid bands 
being especially powerful. The pisiform bone is 
remarkable among its fellows in being isolated from 
the synovial membrane of the rest of the carpus. 
The bone is held to the ulna by the internal lateral 
ligament, and to the fifth metacarpal bone and the 
hooked-proccss of the unciform bone by three stout 
ligaments. 
Viewed as a whole the ligaments of the carpus 
are stronger where they unite the bones of the rows 
than where they unite the parts of the intercarpal 
joint. The ligaments of the ulnar side are stouter 
than are those of the radial. 
The joint between the two carpal rows is convex 
on its proximal surface, where for the radial third it 
is composed of the distal surface of the scaphoid 
bone, and concave for the ulnar two-thirds through 
the lateral surface of the scaphoid bone, and the distal 
surfaces of the semilunar and the cuneiform bones. 
The distal surface is concave at the lateral (radial) 
third, where it is made up by the proximal facets of 
the trapezium and the trapezoid bone; it is convex 
at the median (ulnar) two thirds where the distal sur- 
faces of the os magnum and the unciform bones unite 
to form it. The last-named portion presents well- 
defined lateral facets. 
The two rows are united on the palmar surface 
by an external lateral ligament extending between 
the scaphoid and the trapezium, as well as by a second 
EXPLANATION OF PLATE XXXIX 
Fig. 1. The elbow-joint, seen from in front. 
Fig. 2. The wrist-joint, seen from in front. 
Fig. 3. The elbow-joint, seen from the median side. 
Fig. 4. The wrist-joint, scon from behind. 
Fig. 5. The carpal and metacarpo-phalangeal synovial sacs. PLATE XXXIX 
Fig.] 
Fig. 2 
Fig. 3 
Fig.4 
Fig 5 
T. SmcJair A SonJAk. LIGAMENTS OF THE HAND. 
225 
ligament extending obliquely downward and inward 
from the scaphoid bone to the os magnum. On the 
dorsal surface two oblique ligaments pass between the 
cuneiform bone to the unciform ; one from the semi- 
lunar bone to the os magnun}; another from the sca- 
phoid'bone to the os magnum (this acts as an inter- 
osseous ligament, separating the lateral from the 
median portion of the joint); and yet another from 
the scaphoid bone to the trapezoid bone. 
The Synovial Membrane of the intercarpal articu- 
lation sends processes upward between the bones of 
the first row and downward between those of the 
second, and communicates with the sac between the 
second row and the metacarpal bones. 
The median border of the carpus is strengthened 
by the external lateral ligament of the wrist-joint. 
Movements.-The joint between the two rows is 
freely movable in flexion and extension. The high 
degree of specialization noted in the formation of the 
thumb and index finger is correlated with the forms 
of the joints intervening between them and the fore- 
arm. The lateral third of the joint is restricted 
to the movements of the first row of carpal bones 
upon the trapezium and the trapezoid, these bones 
being in longitudinal serial union with the thumb and 
the index finger.-The largest surface of contact be- 
tween the two rows occurs when the second row is 
strongly extended on the first, as in the act of support- 
ing the body on the hand in creeping.-The median 
two-thirds of the joint, in addition to flexion and ex- 
tension, permit a greater degree of locking to occur 
than in the lateral third.-The lateral facets of the 
socketdike proximal surface act as supporting or 
check facets at the limits of pronation and supina- 
tion.-The interosseous ligament between the sca- 
phoid bone and the os magnum acts as a check to 
pronation. - The carpus when at rest presents the 
second row of bones moderately extended upon the 
first. This is the position instinctively taken after 
injury of the wrist or body of the hand, and is the 
one to which surgical appliances should be adapted. 
The Nerves of the Carpus. The dorsum is sup- 
plied by a branch of the radial nerve; the ulnar 
aspect, by the interosseous nerve and a recurrent 
branch of the ulnar nerve; the radial side by a deep 
branch of the ulnar. The metacarpo-phalangeal and 
the inter-phalangeal joints are supplied by the ulnar 
nerve. 
The Arteries are derived from the anterior and the 
posterior branches of the radial and the ulnar, as well 
as from the interosseous artery and the deep palmar 
arch. 
THE CARPO-METACARPAL AND THE INTER- 
METACARPAL JOINTS AND LIGAMENTS. 
These lines of union are conveniently considered 
together. Two distinct joints are formed between 
the surfaces embraced in the title,-one between the 
first metacarpal bone of the thumb and the trapezium, 
and one between the remaining metacarpal bones and 
the trapezoid bone, the os magnum, and the unciform 
bone.-The first-named joint is saddle-shaped, pro- 
vided with a loose but stout capsule, strengthened by 
two lateral ligaments. The outer of these arises from 
the proximal end of the second metacarpal bone.- 
The second-named joint is nearly flat or sinuate be- 
tween the os magnum, the unciform, and the third, the 
fourth, and the fifth metacarpal bones, but more irreg- 
ular and angulated between the trapezoid bone, the 
trapezium, and the second metacarpal bone. The joint 
is usually strengthened above by two ligaments to 
each metacarpal bone and below by numerous bands. 
The fifth metacarpal bone is united to the unci- 
form by capsule-like bands, recalling the peculi- 
arities of the joint between the first metacarpal bone 
and the trapezium.-Interosseous ligaments unite the 
os magnum and the unciform bone with the third and 
the fourth metacarpal.-An intermetacarpal ligament 
passes between the third and the fourth metacarpal 
bones.-A special palmar ligament extends distally 
and medianly, to unite the trapezium with the third 
metacarpal bone. 
Movements.-The joint between the first meta- 
carpal bone and the trapezium, like saddle-joints else- 
where, permits of free motion in all directions.-The 
joint between the remaining metacarpal bones and the 
trapezoid, the os magnum and the unciform bone, is 
more fixed, but is quite mobile at the fourth and fifth 
metacarpal bones as compared with that at the second 
and third. - The capsule-like ligament at the fifth 
metacarpal bone enables a greater degree of motion to 
be here displayed than at any other portion of the 
carpo-metacarpal line.-The least degree of motion 
takes place at the second metacarpal bone.-The inter- 
osseous ligaments act as checks to extremes of move- 
ment of flexion and extension.-The fourth and the 
fifth metacarpals move together upon the nearly fixed 
third bone. 
THE METACARPO-PHALANGEAL JOINT. 
The distal extremity of each metacarpal bone 
presents a large convex surface that is wider below 
than above, and is joined to a small concave surface 
on the proximal end of the first phalanx. 226 
THE JOINTS AND THE LIGAMENTS. 
The surfaces are united by a capsular ligament 
which presents the following subdivisions :- 
The Anterior Ligament. 
The Posterior Ligament. 
The two Lateral Ligaments. 
The Transverse Ligaments. 
The Anterior Ligament (glenoid ligament) is a 
thickened pad that forms on the palmar surface a 
firm concavity, in which lie the flexor tendons 
of the fingers. The sheath of the tendons is closely 
incorporated with the pad,. Its posterior surface is 
also concave, to receive the palmar aspect of the 
head of the metacarpal bone. 
The Posterior Ligament is weak, bursa-like, and is 
protected by the tendon of the common extensor. 
The Lateral Ligament extends obliquely from the 
posterior tubercle of the lower end of the metacarpal 
bone to the anterior tubercle of the proximal end of 
the first phalanx. It is a powerful ligament, the ex- 
ternal being the stronger, though less strong than 
is the same structure between the phalanges. It is 
stretched by flexion, and relaxed by extension. 
The plan of the metacarpo-phalangeal joint of the 
thumb recalls that of an inter-phalangeal joint in pre- 
senting a small anterior pad, in possessing lateral 
ligaments, and in retaining the phalangeal character 
of both articular facets. 
The Transverse Ligaments, four in number, unite 
by loose broad bands the heads of the four median 
metacarpal bones. They can be felt in the undissected 
hand beneath the skin of the interdigital spaces. 
According to Holden, a furrow of the palm, run- 
ning transversely across the lower third, " corre- 
sponds pretty nearly with the metacarpal joints of 
the fingers, with the upper limit of the synovial 
sheaths of the fingers (that of the little finger ex- 
cepted); also with the splitting of the palmar fascia 
into its four slips." The transverse metacarpal liga- 
ment lies in the same line with the joint. A little 
below the skin-furrow the digital arteries bifurcate 
to run along the sides of the fingers. 
THE INTER-PHALANGEAL JOINTS AND LIGAMENTS. 
The plan of these joints is so similar to the fore- 
going as not to need a detailed description. The 
distal surface of each joint is depressed toward the 
sides and raised in the middle, while the proximal 
surface is raised at the sides and depressed in the 
middle. This peculiarity is least marked in the joint 
between the second and the third phalanges. Exceed- 
ingly stout lateral ligaments strengthen each joint 
that is otherwise unprotected save on the palmar 
surface where a fibro-cartilaginous pad is seen. Over 
this structure the tendons of the flexor muscles play. 
Movements.-Flexion and extension are here alone 
possible. A slight degree of rotation is secured by 
manipulation. 
Prof. Cleland1 has described stout ligamentous 
structures extending from the sides of the phalanges, 
to be inserted into the skin. He assumes that such 
bands aid in retaining the different parts of the integu- 
ment in the positions which they are adapted to 
occupy. 
The inter-phalangeal joints correspond to the 
"knuckles." The line of each joint lies immediately 
in advance of the main prominence of the "knuckle" 
in flexion, and of the transverse concave skin-grooves 
in extension. 
THE JOINTS AND LIGAMENTS OF THE 
LOWER EXTREMITY. 
The Joints and Ligaments of the lower extremity 
embrace the following :- 
Those of the Pelvis. 
Those of the Hip. 
Those of the Knee. 
Those of the Leg. 
Those of the Ankle. 
Those of the Foot. 
The Joints and Ligaments of the Pelvis. 
The bones of the pelvis are held together by four 
joints and their respective ligaments. 
The joints are as follows:- 
The Ilio-Sacral 
The Symphysis Pubis. 
The Sacro-Coccygeal. 
THE ILIO-SACRAL JOINT. 
The two Ilio-Sacral Joints are of the nature of 
symphysis, and in each instance are formed by the ap- 
position of the auricular facet of the innominate bone 
against the lateral surface of the sacrum, a thin disk 
of fibro-cartilage intervening. This disk is friable, 
and frequently possesses a small cavity containing a 
glairy fluid. 
The ligaments of the ilio-sacral joint are- 
The Ilio-Lumbar. 
The Anterior Ilio-Sacral. 
The Posterior Ilio-Sacral. 
1 Journ. of Anat, and Phys., 1878, 526. JOINTS AND LIGAMENTS OF THE PELVIS. 
227 
The Uio-Lumbar Ligament (figs. 1 and 2, Plate | 
XXXIX.) is a stout rounded cord extending from the 
tip of the transverse process of the last lumbar verte- 
bra to the crest of the ilium. 
The Anterior and the Posterior Ilio-Sacral Liga- 
ments are thin layers of fibrous tissue extending from 
the sacrum to the ilium. Some of these bundles are 
transverse, others are oblique. The latter are arranged 
in two fasciculi, the upper extending from the pos- 
terior superior spinous process of the ilium to the 
sacrum ; the lower extending from the posterior in- 
ferior spinous process of the ilium to the sacrum. Of 
the two ligaments the posterior is the stronger. 
The sacro-iliac junction is easily destroyed by crush- 
ing violence. It is thus often involved in fractures 
of the pelvic bones, when its surfaces have been known 
to be separated to the distance of two fingers' breadths. 
Destructive inflammation writh suppuration is asserted 
by Sayre 1 to be a common disease of this articulation, 
and is invariably of traumatic origin. 
Accessory to the ilio-sacral joint are the following 
ligaments:- 
The Greater Sacro Sciatic. 
The Lesser Sacro-Sciatic. 
The Greater Sacro-Sciatic Ligament is a broad mem- 
brane-like structure extending from the outer portion 
of the tuberosity of the ischium to the upper posterior 
portion of the ilium, and the posterior lateral surface 
of the sacrum. It is slightly contracted in the mid- 
dle, but expanded toward either end. Its fibres are 
pierced here and there by minute bloodvessels, and 
are more or less continuous below with the origin 
of the Semi-Membranosus muscle and the long head of 
the Biceps Flexor muscle, and above with the iliac 
fibres of origin of the Gluteus Maximus muscle. 
The ligament converts the great sciatic notch into 
a foramen, and gives origin to some fibres of the 
Gluteus Maximus. 
The inner surface of the ligament at its ischiatic 
attachment is continuous through the so-called falci- 
form process with the obturator fascia covering the 
internal obturator fascia, and in like manner with 
lower fibres entering into the sub-pubic ligament. 
The great sacro-sciatic ligament should be associ- 
ated with the deep fasciae rather than with true liga- 
ments. It is made tense by action of the Biceps 
Flexor muscle, and may be considered mainly in the 
light of an aponeurosis. 
The Lesser Sacro-Sciatic Ligament extends between 
the posterior surface of the spine of the ischium and 
the sacrum, where some of its fibres are continuous 
with the Ischio-Coccygeal muscle. It converts the 
lesser sciatic notch into a foramen. 
The greater and the lesser sciatic foramina trans- 
mit the following structures: the greater, the Pyri- 
formis muscle, the sciatic and the pudic nerve; the 
lesser, the Internal Obturator muscle, and the internal 
pudic nerves and bloodvessels. 
The Obturator Membrane.-In addition to the 
above structures the innominate bones exhibit a firm 
membrane, occupying the foramen of the same name, 
which has received the name of the Obturator Mem- 
brane. It is pierced near its lower border by the 
obturator vessels and nerves, and yields surfaces of 
origin for the Internal and the External Obturator 
muscles. 
THE SYMPHYSIS PUBIS. 
The Symphysis Pubis (figs. 3 and 4, Plate XXXIX.) 
is a joint belonging to the order of symphysis, as the 
name expresses. Like all the members of this group 
it possesses an inter-articular disk of fibro-cartilage. 
Owing to the somewhat bevelled appearance of the me- 
dian articular surfaces of the pubic bones, a V or Y 
shaped interval results as they approach one another. 
The fibro-cartilage of necessity takes the shape of this 
interval, and is further peculiar in being composed 
chiefly of cartilage in the basal portion of the V or 
Y, and of fibro cartilage in the expanded portion. 
Moreover, the lateral portions of the disk are in in- 
timate union with the tit-like eminences on the pubic 
surfaces, and retain this connection even after mace- 
ration. Not only is the yielding centre of the disk the 
least fixed of the parts, but it is occupied by a syno- 
vial sac. This, in the young of both sexes, and in the 
male adult, is placed at the basal part of the V or in 
the stem of the Y, and extends thence forward barely 
to the centre of the joint. It averages in the adult 
male a size not greater than that of a split pea. The 
sac is larger in adult females, and in the parturient 
may involve the entire thickness of the joint. A 
moderate degree of motion is possible between the 
innominate bones during pregnancy and parturition.1 
The position of the symphysis can be felt from within 
the vagina. 
The symphysis is strengthened by accessory fibres 
1 Orthopedic Surgery, etc., 327. 
1 See in this connection J. M. Duncan, Edin. Med. Journ., 1855. 228 
THE JOINTS AND THE LIGAMENTS. 
both in front and behind. Those in front are called 
the Anterior Pubic Ligaments; and those behind 
the Posterior Pubic Ligaments, and are unimportant. 
A slender band passing over the tops of the pubic 
bones has received the name of the Superior Pubic 
Ligament. A more important arrangement of fibres 
than the above, is the Sub-Pubic Ligament. It oc- 
cupies the upper narrowed portion of the sub-pubic 
arch, and is composed of an intricate interlacement 
of fibres, which results in the formation of a stout 
membrane. It is attached above to the under surface 
of the symphysis, but below is free. 
THE SACRO-COCCYGEAL JOINT. 
The Sacro-Coccygeal Joint is of the same nature 
as the intervertebral disks, and does not demand a 
separate description. The joint is supported by ante- 
rior and posterior bands that have received the names 
of the Anterior and the Posterior Sacro-Coccygeal 
Ligaments. 
The Hip-Joint. 
The hip-joint (fig. 1, Plate XLI.) serves to hold the 
innominate bone and the femur together. It belongs 
to the enarthrodia, and consists of the acetabulum, 
the head of the femur, and associated ligaments. 
The cartilage lining the acetabulum is thicker at 
the margins than at the centre, while the cartilage 
covering the head of the femur is thicker at the centre 
than at the sides. These surfaces are thus mutually 
adapted. 
The following ligaments are described in connection 
with the hip-joint:-■ 
The Cotyloid. 
The Transverse. 
The Capsular. 
The Ligamentum Teres. 
The Synovial Membrane. 
The Cotyloid Ligament is a prismoid elevation of 
fibro-cartilage whose base corresponds to the osseous 
lips of the acetabulum. It assists in deepening the 
socket, while slightly narrowing it at the rim. It is 
thinner at the anterior and at the posterior borders 
than elsewhere, and is composed of freely interlac- 
ing fibres that ascend obliquely from the bone. 
The Transverse Ligament is a simple band of fibro- 
cartilage extending between the opposite borders of the 
cotyloid notch. It converts the notch into a foramen, 
through which bloodvessels and nerves pass into the 
joint. 
The Capsular Ligament is attached above to the in- 
nominate bone, and to the transverse and the cotyloid 
ligaments. Below it terminates at the spiral line of 
Fig. 76. 
The hip-joint seen from in front. It is dissected to display the ilio-femoral 
fascicle. 
the femur anteriorly, to the lower third of the neck 
posteriorly, as well as to the bone at points intermedi- 
ate between these. The capsule is much thicker at 
the upper, the outer, and the anterior portions than at 
the inferior and the inner, where it is thin and weak; 
The fibres are arranged in oblique, longitudinal, and 
circular bundles. Of these the longitudinal are the 
EXPLANATION OF PLATE XL. 
Fig. 1. The ligaments of the pelvis and of the hip-joint, 
seen from in front. 
Fig. 2. The ligaments of the pelvis, seen from behind. 
Fig. 3. A frontal section of the symphysis pubis. 
Fig. 4. A horizontal section of the symphysis pubis. PLATE XL 
Fi g. 2 
Fig. 4 
Fig. 3 
Fig.l 
T. Sinclair & 5on,Lith.. THE IIIP-JOINT. 
229 
most important, and extend for the most part along 
the front of the joint. 
A superficial fascicle of great strength (ilio-femoral 
or Y-shaped ligament), triangular in form, with its 
base directed downward, is attached above to the 
anterior inferior spinous process of the ilium, to 
the space between it and the rim of the acetabulum. 
It passes downward and outward, and finally bifur- 
cates at the neck of the femur, one bundle going to 
the spiral line, the other to the depression in front 
of the lesser trochanter. (See Fig. 76.) In the inter- 
val between these branches the deep layer of fibres 
of the capsule is seen. The anterior surface of the 
capsule is in close relation with the Gluteus Minimus 
muscle, and less intimately with the reflected tendon 
of the Rectus Femoris, and the conjoined tendon of 
the Iliacus Internus and Psoas Magnus. Between 
the ligament and the last-named muscles a bursa is 
seen, which often communicates with the interior of 
the joint. 
The ischio-capsular (ischio-femoral) bundle is at- 
tached above to the ischial rim of the acetabulum and 
the smooth surface between it and the great sciatic 
notch. The fibres pass horizontally outward, and are 
lost in the capsule.-A small accessory fascicle, the so- 
called pubo-capsular ligament (pectineo-femoral) is at- 
tached beneath the Pectineus muscle from the pubic 
border of the obturator foramen or the cotyloid notch, 
and extends thence to the capsule.-A process of the 
iliac fascia is detached opposite the pectineal eminence, 
and passes between the Iliacus Internus and the Pec- 
tineus muscle to the capsule.-At points between the 
above-mentioned fascicles the capsule is weak, and com- 
posed of circular and oblique fibres. Of these the cir- 
cular are the most important. They are especially 
well developed behind, where they embrace the neck 
of the femur, and run parallel to the fibres of the 
Internal Oblique muscle, forming a collar-like band 
about its lower third, but without attachment to the 
bone. The synovial membrane is reflected from the 
femur to the capsule at this point. 
The Ligamentum Teres is not round, as the name 
would imply, but flat. It arises from the edges of 
the cotyloid notch by two distinct fascicles, which are 
attached to tlie transverse ligament, and by a third 
less defined root, which is derived from the border of 
the depressed base of the acetabulum that supports 
a cushion of fat. The ligament ascends round the 
head of the femur, to be attached to a depression a 
little below the centre. The ligamentum teres is 
broader and more compact at its upper than at its 
lower attachment. It tends to check rotation out- 
ward in the flexed position. 
The Synovial Membrane is in contact with the 
opposing surfaces, encloses the round ligament, and 
is supported by the lower and inner parts of the 
capsule. 
Movements.-The movements of the hip-joint con- 
sist of extension, flexion, adduction, abduction, and 
rotation. The terms eversion and inversion, while 
referring to the limb as a whole, are determined by 
the hip-joint. Eversion of the limb corresponds to 
extension with rotation outward, inversion to exten- 
sion with rotation inward. Rotation is naturally less 
exact when the joint is extended than when it is flexed, 
since in the first-named position the movement is re- 
stricted by the tense ilio-femoral fasciculus, while in 
flexion the relaxed capsule and the tense ligamentum 
teres-in the event of flexion being combined with 
rotation outward-alone restrict it. Extremes of 
rotation upward are checked by tension of the lower 
part of the capsule as well as by the contact of the 
lower border of the neck against the upper margin of 
the acetabulum. - Extreme of rotation downward 
brings the most convex portion of the head against 
the shallowest part of the socket. The movement is 
checked by the ilio-femoral fasciculus. 
Dislocations of the hip will be determined by the 
ineffective resistance presented in the checks to the 
various movements of the joint. It will require a 
greater force to effect dislocation in extension than in 
flexion, and in flexion with adduction than in flexion 
with abduction. 
In addition to the above elementary statement of 
the hip-joint movements, the following more elabo- 
rate description is herewith presented. 
Extension is effected by the head of the femur being 
thrown forward, and one-half of its anterior surface, 
viz., that answering to the anterior aspect of the neck, 
brought out of the acetabulum, while a small portion 
of the under and posterior surface lies within that 
cavity. In extension the ilio-femoral fasciculus is 
tense. 
Flexion is the reverse of the above-named move- 
ment. The anterior aspect of the head and a small 
portion of the neck now recede within the acetabulum, 
while the upper and posterior parts are brought out. 
In flexion the ischio-femoral fasciculus is tense, and 
the ilio-femoral relaxed. In flexion combined with 
adduction the lower portion of the head passes well 
within the acetabulum, but is free near the neck else- 230 
THE JOINTS AND THE LIGAMENTS 
where. The ligamentum teres is tense. In flexion 
combined with abduction the head passes entirely 
within the socket superiorly, but inferiorly is brought 
out, and is supported by the lower and the inner part 
of the capsule, which is now tense, while the liga- 
mentum teres is relaxed. 
It follows, from what has been seen of the relative 
degrees of strength of the parts of the capsule, that 
the joint is best protected in the position of extension, 
and least so in the position of flexion with abduction. 
Rotation is defined in two ways,-rotation with 
extension, and rotation with flexion. The first-named 
is necessarily limited, since it takes place while the 
powerful ilio-femoral ligament is tense. In the living 
subject it is best measured by the arc of movement of 
the great trochanter. Rotation with flexion is free in 
all directions save that of flexion with adduction, 
which is checked by the tension of the ligamentum 
teres. 
The extreme of upward movement is checked by 
tension of the lower part of the capsule as well as by 
contact of the lower border of the neck against the 
upper border of the acetabulum. The extreme of 
downward movement is checked by the forced con- 
tact of the head against the most convex portion of 
the tense ilio-femoral fasciculus. 
Rupture of the ilio-femoral fasciculus would cause 
dislocation on extension of the joint, as in the act of 
standing erect. A wrench of the femur downward 
and backward while the thigh is raised, and the joint 
flexed, would cause dislocation, since in this position 
the weight is thrown against the weak posterior and 
under part of the capsule. The liability to luxation 
is increased if the joint is adducted. 
An exact knowledge of the actions of the ilio- 
femoral fasciculus in retaining the head of the femur 
in its false positions during dislocation has been shown 
by Dr. II. J. Bigelow 1 to be of great importance. 
This observer has found the external branch of the 
fasciculus in dorsal dislocation to hold the limb in an 
inverted position. Should eversion exist with this 
dislocation, the external branch of the ligament is rup- 
tured. In anterior oblique dislocation the head of the 
femur is hooked over the ligament, which is entire. 
In supra-spinous dislocation the head, as in the pre- 
ceding example, is hooked over the ligament, but the 
external branch is ruptured. In pubic dislocation 
the range of the femur upon the pubes is limited by 
the ligament, which in the sub-spinous dislocation 
also binds the neck of the femur to the pelvis. In 
the thyroid dislocation the limb is everted by the 
agency of the ligament, and the trochanter rests upon 
the pelvis. In dislocations which are the result of 
extreme force the ilio femoral fasciculus is ruptured. 
Congenital dislocation of the hip, by altering the 
lines of pressure of the trunk upon the inferior ex- 
tremity, induces pronounced anterior inclination of 
the pelvis, a condition which acts indirectly as a 
cause of antero-posterior curvature of the lumbar 
vertebrae. 
The cervical portion of the capsular ligament is 
subject to many variations. It has been found by Dr. 
G. K. Smith1 that the ligament may be attached to the 
neck nearer the head in some subjects than in others. 
The hip-joint receives Nerves on the posterior sur- 
face from the ischiatic nerve as it supplies the Gemel- 
lii and the Quadratus Femoris muscles, and on the 
anterior surface from a branch of the obturator nerve. 
The Arteries giving branches to the hip-joint are 
the internal circumflex, the gluteal, the obturator, and 
the sciatic. 
The Knee-Joint. 
The knee (figs. 2, 3, 4, Plate XLI.) is the largest and 
most complicated joint in the body. It is composed 
of the femoral condyles, the tibial condyloid surfaces, 
and the patella, together with a pair of inter-articular 
disks, the whole being bound together with appropri- 
ate ligaments. 
The joint thus presents for examination- 
The Capsular Ligament. 
The External Lateral Ligament. 
The Internal Lateral Ligament. 
The Inter-Articular Cartilages. 
The Transverse Ligament. 
The Crucial Ligaments. 
The Synovial Membrane. 
The Capsular Ligament is united to the margin of 
the glenoid cavities of the tibia below, and the tuber- 
osities and lower portion of the popliteal surface of 
the femur above. It is in addition attached to the 
margin of the patella and to the patellar ligament in 
front, as well as to the outer broad surfaces of the semi- 
lunar cartilages at the sides. It is of unequal strength 
and thickness, being strong behind, but weak in the 
neighborhood of the patella. It is incorporated be- 
hind with the tendon of the Semimembranosus mus- 
cle, at the side with the lateral ligaments, at the front 
1 The Insertion of the Capsular Ligament of the Hip-Joint and 
its Relation to Intra-Capsular Fracture. Pamphlet. New York, 
1862. 
The Hip. THE KNEE-JOINT 
231 
and the inner side with an aponeurotic expansion from 
the Vastus Internus and the Sartorius muscles, and at 
the front and the outer side with an expansion from 
the fascia lata. 
The capsular ligament is strengthened by the liga- 
mentum patellae-a structure representing the tendon 
of the Quadriceps Extensor muscle as it lies between 
the patella above and the tubercle of the tibia below. 
It is slightly broader at its upper than at its lower 
attachment, and is continuous at its outer margin 
with the capsule. Between the ligament and the skin 
is lodged a quantity of fat, while between the liga- 
ment and the tibia lies an important bursa. Behind, 
the thick, flat, and unyielding capsule (here often 
called the Ligamentum Winslowi) is composed for 
the most part of vertical fibres, which are to some 
degree in association with the tendons of the Gastro- 
cnemius, the Popliteus, and the Plantaris muscles. A 
well-defined superficial oblique bundle (oblique fasci- 
culus), which serves as a reflection of the tendon of 
the Semimembranosus muscle, is directed upward and 
outward. 
Under the name of the ligamentum arcuatum is 
described a fascicle which is attached above at the 
outer femoral condyle, and below to the inter-condyl- 
oid fossa beneath the oblique bundle. The deepest 
portion of this accession answers to the capsule, as it 
covers the bursa lying beneath the tendon of the Pop- 
liteus muscle. At its lower border the fascicle re- 
ceives some of the fibres of the Popliteus muscle, as 
well as a few ligamentous bands attached below to 
the head of the fibula between the insertion of the 
Biceps and the origin of the Soleus muscle. 
Notwithstanding its great strength the posterior 
portion of the capsule will yield to pressure from an 
abscess or aneurism. In this manner pus or blood 
may reach the interior of the joint from the ham. 
Of the former lesion J. Adams 1 reports an example. 
In the course of the treatment of an abscess which 
had been opened through the skin this writer observed 
that the pus ceased flowing at a time coincident with 
swelling of the joint. A free incision being made, a 
quantity of pus escaped from the interior of the joint, 
and an opening was discovered in the posterior cap- 
sular fibres, by means of which the abscess in the 
ham had communicated writh the joint. Both the 
Ligamentum Winslowi and the popliteal artery have 
been ruptured by the fall of a sack of wheat on the 
thigh. 
The External Lateral Ligaments are two in number 
-the long and the short ligament. The long liga- 
ment is a stout rounded eord extending from a small 
prominence situated above the sulcus, near the 
Poplitcus muscle, and in front of the point of origin 
of the outer head of the Gastrocnemius. It passes 
downward on the line of the fibula, and is attached to 
the outer part of the head of that bone. A bursa is 
often seen between it and the tendon of the Biceps. 
The ligament closely resembles the last-named ten- 
don, and passing as it does along its anterior border 
may be confounded therewith. Inferiorly it becomes 
united with the tendon, and sends an expansion to 
the patella. 
The short external lateral ligament is a fasciculus, 
variable in size, attached above to the outer femoral 
tuberosity, and passing downward and outward to the 
styloid process of the fibula. It is often connected 
with the tendon of the Popliteus muscle, and may end 
either on the capsular ligament or the tibial aponeu- 
rosis. 
The Internal Lateral Ligament is a broad mem- 
branous expansion passing from the inner femoral 
condyle from a point below the tubercle for the 
attachment of the Adductor Magnus muscle, down- 
ward and outward to be attached to the correspond- 
ing tuberosity and the anterior surface of the shaft 
of the tibia. Superficially the ligament, as it lies on 
the tibia, is in relation with the aponeurotic structures 
of the tendons of the Sartorius, the Gracilis, from 
which it is separated by a bursa, and the Semitendi- 
nosus muscles, and,- on a deeper plane, with the aponeu- 
rosis of the Vastus Internus muscle. Beneath lies a 
considerable portion of the Semimembranosus muscle. 
The deeper fibres of the ligament are attached to the 
posterior part of the corresponding interarticular 
cartilage, and is in contact with the synovial mem- 
brane. The ligament is further attached to the 
aponeurosis covering the Popliteus muscle, and to the 
oblique fibres of the ligament of Winslow. 
Rupture of the internal lateral ligament with dis- 
placement of the semilunar cartilages is instanced in 
the following case recorded by Adams.1 A man aged 
thirty-two while in the sitting position received a 
blow upon the inner part of the knee. Forced ab- 
duction followed with undue mobility. An abnormal 
interval measuring three-fourths of an inch in width 
existed between the extremity of the femur and the 
head of the tibia. Recovery was secured with a good 
limb. 
The Interarticular Cartilages (semilunar cartilages 
' Lancet, 1859, 155. 
* Med. Times and Gaz., 1857, 603. 232 
THE JOINTS AND THE LIGAMENTS. 
or disks) are two in number, and are named from 
their position the internal and the external cartilage. 
They are wide and thick without, but thin and com- 
pressed within, and apparently belong to the tibia to 
the plane of whose articular surfaces they correspond. 
The lower surfaces are flat, while the upper are con- 
cave for the reception of the femoral condyles. Each 
cartilage covers one-third of the tibial articular sur- 
face, to the border of which it is fixed by short 
fibrous bands, which collectively receive the name of 
the coronary ligament. The internal cartilage is of a 
semilunar figure, narrow and pointed in front, and 
to a moderate degree fixed to the anterior border of 
the anterior tibial concavity. It passes backward to 
be attached to the inner side of the intercondyloid 
notch. The ends of the cartilage are separated by 
the entire breadth of the tibial surface. The internal 
cartilage is in marked contrast to the external, since 
it sends off no fibres to the crucial ligament. The 
external cartilage is more circular in form than the 
internal, and is grooved upon its outer side by the 
tendon of the Popliteus muscle. It is attached in 
front to the depression in advance of the spine of the 
tibia, and behind, for the most part, to the space be- 
tween the two tubercles of the spine of the tibia. 
The anterior and the posterior ends of this cartilage 
are of the same size, and are so near each other as 
to lie within the curve of the internal cartilage, 
which thus corresponds to the arc of a larger circle 
than the one described by the external. Small bun- 
dles of fibres pass from the external cartilage to the 
crucial ligament. 
The Transverse Ligament is a narrow band of 
fibres stretching across between the anterior extremi- 
ties of the interarticular cartilages. 
The Crucial Ligaments, or crossing ligaments, are 
broad though short bands, two in number, and named 
from their position the anterior and the posterior, 
extending from the space before and behind the 
spine of the tibia to the posterior condyloid notch 
of the femur. The two in crossing describe a figure 
resembling the letter X, and form a kind of partition 
between the right and the left sides of the joint. 
Both ligaments are connected with the external inter- 
articular cartilage. 
The anterior crucial ligament is attached anteriorly 
to the inner side of the depression in front of the 
spine of the tibia. It lies in front of the external 
interarticular disk, with which it is in part blended. 
It increases in breadth as it passes upward and out- 
ward, and is attached above to the inner and hinder 
part of the inner surface of the external condyle. 
The posterior crucial ligament is broader and stouter 
than the anterior, and is attached below to the 
depression behind the spine of the tibia. Gaining 
a slight accession from the external interarticular 
cartilage, it passes upward and a little outward to be 
attached to the posterior condyloid femoral notch 
(which it for the most part occupies) as well as by a 
few fibres to the outer side of the inner condyle. 
The crucial ligaments may be ruptured by violence. 
Mr. Poland1 records a case of a man forty years of age 
who incurred an injury of the right knee by a sack 
of wheat falling upon the thigh of the corresponding 
side. Amputation was found to be necessary, owing 
to rupture of the popliteal artery. Examination of 
the knee demonstrated rupture of the anterior crucial 
ligament. 
The Synovial Membrane is more extended than any 
other in the body. In addition to lining the capsular 
ligament, and covering the articular surfaces of the 
bones entering into the joint, it is reflected from the 
fat lying between the ligamentum patellse and the 
space in front of the head of the tibia ; surrounds the 
crucial ligaments and the tendon of the Popliteus 
muscle; is reflected upon the interarticular cartilages, 
and is in contact with the internal lateral ligament at 
the inner condyle of the femur. The membrane con- 
forms, as a rule, to the shape of the capsular ligament, 
but above it extends as a cul-de-sac beneath the 
tendon of the Quadriceps Extensor muscle to the 
distance of several inches. Below to its outer side 
(and guarded by the tendon of the Popliteus muscle) 
it sends a prolongation backward and outward upon 
1 Med. Times and Gazette, 1866, 6. 
EXPLANATION OF PLATE XLI. 
Fig. 1. The hip-joint, seen from in front. 
Fig. 2. The knee-joint, seen from behind, showing capsule. 
Fig. 3. The knee-joint, seen from the median side 
Fig. 4. The knee-joint, seen from behind, showing position 
of the disks and the crucial ligaments. The names 
"Internal Condyle" and "External Condyle" should 
be transposed. PLATE XLI 
Fig .1 
Fig. 2 
Fig.8. 
Fig. 4. 
T Sinclair & Son.Lith. THE KNEE-JOINT. 
233 
the outer border of the external interarticular carti- 
lage toward the tibio-fibular articulation, with which 
it communicates, it is estimated, in one out of every 
six cases. Behind it passes between the femoral con- 
dyles and the origins of the Gastrocnemius muscle. 
Synovial fringes are present at the lower and front 
part of the joint, and are especially conspicuous about 
the lateral margins of the patella and the interartic- 
ular cartilages to constitute the two alar ligaments, so 
called. These, beginning at the front and at the sides 
of the joint below, unite in a rounded cord containing 
a few ligamentous fibres, and are prolonged backward 
and upward to the front of the upper condyloid notch. 
Beneath the synovial membrane at the sides of the 
patella, and in front of the femur, a quantity of fat is 
deposited. 
When the knee is extended, the top of the cul-de 
sac lies two inches above the upper margin of the 
patella. In the flexed position it is lower. Inferiorly 
the synovial membrane lies a little above the level 
of the upper part of the head of the fibula. 
Cysts forming in the ham are liable to be fixed to 
the inner tendon of the Gastrocnemius (five cases in 
twenty); when situated in the middle of the ham there 
may be hernial protrusions of the synovial membrane 
of the knee-joint through the posterior portion of 
capsules (six cases in twenty). They are frequently 
complicated with hydrarthrosis.1 
The form of the capsule can be often made out in 
some of the forms of distension with synovial effusion. 
Thus the swelling is apt to be rounded and uniform 
at the inner side of the joint, while inconspicuous and 
irregular on the outer side. The patellar cul-de-sac 
may be measurably separated from the rest of the 
joint, and the prolongation about the tendon of the 
Popliteus muscle may be completely separated from 
the main cavity of the joint. 
Movements.-The movements of the knee-joint 
are both gliding and rolling. The gliding occurs 
between the external condyle of the femur and 
the external interarticular disk, and between the 
posterior half of the internal condyle and the internal 
articular disk, as well as at the patellar groove 
between the patella and the outer condyle. The 
rolling takes place between the interarticular disks 
and the tibial condyles, especially at the outer half of 
the joint and between the narrow oblique facet inter- 
polated between the internal condyle and the patellar 
groove, which has received the name of the oblique 
facet of Meyer. 
Without the aid of the interarticular disks none of 
the above motions can be effected. The disks convert 
the sinuate or flat tibial surfaces into shallow cavities 
admirably adapted to serve as sockets for the femoral 
condyles. The differences in the shapes of the con- 
dyles as contrasted with those of the interarticular 
disks indicate that the lines of action of each of the 
condyles are distinct. Flexion and extension, which 
are in this sense equivalent to the action of gliding, are 
more complete in the outer than in the inner half of 
the joint. In this connection it is well to remember 
the less fixed and more rounded form of the outer 
disk as compared with that of the inner, and the 
decided manner in which the ligaments check the 
extremes of motion. The longer external lateral 
ligament, for example, is a well-defined cord-like 
band of great strength placed further back than is 
the internal lateral ligament. It is, therefore, of 
the two the more thoroughly relaxed, while in 
extension the same ligament is made proportionally 
more tense. As the joint is flexed, a disposition 
exists for the tibia to rotate upon its longitudinal axis. 
This movement takes place, it is thought, between the 
external femoral condyle and the external disk acting 
as one factor, and the outer tibial condyle as the other. 
Meyer estimates that the degree of rotation here 
effected is in direct ratio to the angle of flexion of the 
limb at the knee, when it is seen of necessity to be 
dependent upon the extent to which the ligaments of 
the external condyle have become relaxed. Flexion 
of the outer half of the joint is limited by the anterior 
crucial ligament which becomes tense in extreme 
flexion, while extension is limited by the posterior 
crucial ligament. In moderate degrees of flexion, 
namely, those that most likely occur in the acts of 
walking, sitting, etc., the anterior crucial ligament is 
relaxed. 
In flexion of the inner half of the knee the move- 
ment is seen to be guarded by the weaker and fascia- 
like internal lateral ligament which is placed well 
forward, as also by the broad bands accessory to the 
capsule at this place. The posterior crucial ligament 
assists the internal lateral -ligament in keeping the 
inner condyle in position, but the last-named, as has 
already been seen, is less relaxed in flexion. 
The rotatory movement at the inner side of the joint 
is also much less pronounced than at the outer. On 
the other hand, the rolling motion between the inter- 
nal disk and the inner femoral condyle at the oblique 
facet is increased, and a peculiar curve upward and 
inward is described, that has been compared to the 
figure of the spiral, hence the name of screw-motion 
1 Foucher, Archiv. de Medecine, 1856. 234 
THE JOINTS AND THE LIGAMENTS. 
that Meyer has given to it. This movement of the 
knee is seen, it is thought, in the act of raising the 
leg and bringing it over the thigh of the opposite side. 
Potatory movements of the knee are limited by the 
crucial and the capsular ligaments. 
Extremes of flexion and extension are liable to be 
followed by rupture. The lesions of this class have 
been formulated by L. Dittel1 as the result of ex- 
periments upon the dead body. This observer, by 
forcibly flexing the knee in a specimen prepared by 
removal of the muscles, found that the anterior crucial 
ligament ruptured at its femoral attachment. By 
placing the knee of a similarly prepared limb over 
the interval between two blocks, a violent blow with 
a mallet (thus imitating the force of hyper-extension) 
caused in some instances rupture of the posterior cru- 
cial ligament at its femoral attachment.-In another 
series of experiments a strong man placed the lower 
extremity of the subject over his shoulder with the 
posterior surface of the knee upward, and induced 
hyper-extension of the knee by forcibly dragging the 
leg downward. This experiment performed upon a 
young individual separated the tibial epiphysis pos 
teriorly, the ligaments remaining for the most part 
uninjured; upon old individuals the femoral con- 
dyles irregularly fractured the tibial articular sur- 
faces, the ligaments, as before, being preserved intact. 
If in the latter experiment the leg was carried at a 
right angle to the femur, both crucial ligaments were 
found ruptured,-the anterior at its femoral, the pos- 
terior at its tibial attachment.-In forced abduction 
of the extended joint the internal lateral ligament was 
found ruptured in the middle, or at the tibial or femo- 
ral end. In forced adduction similar lesions occurred 
in the external lateral ligament. 
Movement outward is checked by a band of the 
capsule which has received the name of the lateral 
accessory Uy ament of Henle, while movement inward 
is checked by an analogous band on the median side 
of the joint called the median accessory ligament of 
Henle. Rotations in the extremes of extension and 
flexion are checked by the crucial ligaments, partic- 
ularly by the anterior. 
The knee, while thus seen to be capable of extreme 
flexion, does not possess this function so exactly as 
does the elbow joint, with which of all the joints the 
knee can be most advantageously compared. In the 
elbow, for example, the Brachialis Anticus lies upon 
the flexor aspect, and determines an exact line of 
bending. No similar muscle is situated upon the 
flexor surface of the knee. The flexors instead are 
placed at the sides, and are therefore modified flexors 
only, since they not only flex, but incline the limb 
toward the side where the bending forces are the 
strongest. 
The knee is farther assisted in maintaining the 
apposition of its several parts by the fascia lata, espe- 
cially that portion which lies in direct line with the 
Tensor Vaginae Femoris muscle.1 
Nerves.-The knee-joint receives upon its anterior 
surface a branch of the long saphenous nerve ; upon its 
external and anterior surface a branch of the peroneal 
nerve (this twig lies in company with an articular 
artery); externally and posteriorly by a twig of the 
anterior tibial nerve; internally (medianly) by a twig 
from the posterior tibial nerve; externally by a recur- 
rent branch of the deep branch of the peroneal nerve, 
while the interior of the joint through the posterior 
crucial ligament receives a branch of the posterior 
tibial nerve.2 
The Tibio-fibular Articulations. 
The tibia and the fibula are joined (fig. 1, Plate 
XLII.) by two simple articulations called from their 
positions the superior and the inferior tibio-fibular 
joints. 
The superior tibio-fibular joint surfaces are oval in 
form, nearly flat, and obliquely disposed. The tibial 
surface is the larger, and looks downward and out- 
ward. The synovial membrane is rather loose, and 
occasionally communicates with the sheath of the 
Popliteus muscle, and thence with the knee-joint. 
The tendon of the Biceps Femoris muscle is of equal 
value with the ligaments in maintaining the appo- 
sition between the facets of the joint. 
The superior ligaments are two in number- 
The Superior Anterior Tibio-Fibular Ligament. 
The Superior Posterior Tibio-Fibular Ligament. 
The Superior Anterior Tibio-Fibular Ligament is 
attached in front to the external condyle of the tibia, 
and passes downward and outward to be attached 
behind to the head of the fibula. 
The Superior Posterior Tibio-Fibular Ligament is a 
single thick, short band extending from the tibia at 
the lower border of the groove for the tendon of the 
Popliteus muscle to the head of the fibula. It is 
covered by the last-named muscle. 
* For additional literature upon lesions of the ligaments, etc., of 
the knee, see A. Bruce, Trans. Path. Soc., London, vol. xviii.- 
Guy's Hosp. Reports, 1867. Lancet, 1859, ii. 240. 
2 H. Meyer, Virchow's Archiv., vol. xii. 124, 1857. 
* Stricker's Med. Jahrbucher, 1876, 319. THE ANKLE-JOINT. 
235 
The inferior ligaments are three in number- 
The Inferior Anterior Tibio-Fibular Ligament. 
The Inferior Posterior Tibio-Fibular Ligament. 
The Inferior Interosseous Membrane. 
The Inferior Anterior Tibio-Fibular Ligament is of 
a triangular shape, and is attached to the anterior 
border of the tibia just above the surface articulating 
with the astragalus. It passes obliquely downward 
and outward to the anterior part of the external 
malleolus. This ligament projects a short distance, 
viz., about two lines beyond the articular surfaces it 
serves to unite. It is here covered with cartilage, 
and is continuous with the ankle-joint. It is some- 
times composed of from two to three distinct fas- 
ciculi. 
The Inferior Posterior Tibio-Fibular Ligament is 
shorter than the anterior. It passes from the tibia 
downward and outward to be fixed at the internal 
border of the groove upon the posterior part of the 
external malleolus. Both of the inferior ligaments 
are of great strength, and serve not only to sustain 
the fibula in apposition to the distal end of the tibia, 
but to assist the proximal end as well. 
The Inferior Interosseous Ligament is triangular in 
form, with its base directed downward. Its oblique 
fibres intimately unite the tibia and the fibula between 
their contiguous surfaces at the lower three-fifths of 
their shafts. It is continuous above with the inter- 
osseous membrane. The small synovial surface is 
continuous with the ankle-joint. 
The tibia and the fibula in addition to the above 
joints are connected by the interosseous membrane. 
The Interosseous Membrane. 
The Interosseous Membrane (superior interosseous 
ligament) (fig. 1, Plate XLII.) passes between the 
external border of the tibia and the external ridge 
of the fibula. It is broader above than below, but 
does not entirely occupy the interosseous space. The 
deficiency at the upper part of the space permits the 
passage of the anterior tibial artery, while the one 
below accommodates the peroneal artery and vein 
in their passage from behind forward. 
Remarks.-The movements of the superior articu- 
lation are much freer than those of the inferior. The 
lateral motion of the fibula against the tibia is greater 
than the disto-proximal motion. The latter, indeed, 
is of necessity slight, owing to the overlapping of 
the tibial condyle at the superior fibular facet, the 
shortness of the fibres of the inferior group of liga- 
ments, and the strength of the middle external lateral 
fascicle. 
Nerves. The superior tibio-fibular joint receives 
its nervous supply posteriorly from a twig from the 
posterior tibial nerve as it supplies the Popliteus 
muscle, and anteriorly from a recurrent branch from 
the peroneal nerve. 
The Ankle-Joint. 
The parts entering into the ankle-joint (fig. 1, 4, 
Plate XLII.) are the tibia, the fibula, and the astra- 
galus. The union of the tibia and fibula forms a sort 
of arch or mortise having a greater breadth from side 
to side than from before backward to receive the 
proximal surface of the astragalus. 
The antero-posterior curve in the last-named sur- 
face is greater than that derived from the tibia and 
the fibula, so that all of the astragalar surface is not 
in contact with the mortise at one time. The pos- 
terior end being about one-sixth smaller than the 
anterior, it follows that the lateral borders slightly 
diverge from before backward. In addition to this 
the sides of the astragalar surface are abrupt. The 
inner, the shorter of the two, is inclined somewhat 
outward; the outer is abruptly deflected outward at 
its lower end; the external malleolus may thus im- 
pinge upon the astragalus when the trunk is in the 
erect position. 
The posterior portion of the superior astragalar 
surface exhibits a distinctive facet for articulation 
with the surface of the inferior interosseous ligament 
entering into the joint. 
The ankle-joint is composed of- 
The Internal Lateral Ligament. 
The External Lateral Ligament. 
The Synovial Membrane. 
The Internal Lateral Ligament (deltoid ligament), 
the stoutest of the ligaments of the ankle-joint, is a 
broad, coarsely fasciculated structure attached above 
to the internal malleolus, and below, by a broad line, 
to the astragalus, the calcaneum, and the scaphoid 
bone. It consists of two layers-a superficial and 
deep. The superficial and larger layer is attached 
above to the apex and the sides of the malleolus, and 
below to the points already mentioned. The deep 
layer is much shorter than the superficial. It passes 
downward and backward to connect the deep portion 
of the internal malleolus with the astragalus. 
The superficial layer is divided into two more or 
less distinct anterior and posterior fasciculi. The 
anterior fasciculus is thinner than the posterior. It is 
attached above to the anterior border of the internal 
malleolus, and below to the inferior calcaneo-sca- 236 
THE JOINTS AND THE LIGAMENTS. 
phoid ligament and the scaphoid bone. It extends 
the length of the median border of this ligament.- 
The posterior fasciculus, somewhat rectangular in 
shape, is attached above to the inferior surface of the 
superior aspect of the internal malleolus, and below 
to the astragalus and the calcaneum. 
The internal lateral ligament protects the surface 
of contact with the internal malleolus in all its 
motions. 
The External Lateral Ligament, conventionally so 
called, is composed of three distinct ligaments, named, 
from their relative positions, the anterior, the middle, 
and the posterior fascicles.-The anterior fascicle, the 
shortest of the three, is attached above to the anterior 
border of the external malleolus; it passes almost 
horizontally forward and inward to be attached to 
the astragalus at the junction of the neck and the 
body. It often splits into two bundles. In flexion it 
touches the anterior tibio-fibular ligament.-The mid- 
dle fascicle, the longest of the three, is also the strong- 
est. It assumes the form of a rounded cord, which is 
fixed above to the fibula directly in front of the apex 
of the external malleolus, and below to the external 
surface of the calcaneum.-The posterior fascicle, the 
weakest of the three, and more deeply situated than 
the others, passes nearly horizontally inward from 
a groove on the inner side of the external malleolus 
to the posterior surface of the astragalus on the groove 
between the upper and the lower articular surfaces. 
In extension of the ankle-joint this ligament touches 
the lower border of the posterior inferior tibio-fibular 
ligament. 
No capsule, properly speaking, exists at the ankle- 
joint. The joint is protected in front and behind by 
dispositions of fibres having little strength. The 
fibres of the posterior set have the same general 
arrangement as those of the ligament last named. 
The Synovial Membrane is unyielding on the sides 
where it answers to the malleoli, ^.nd where it lies in 
contact with the ligaments of the ankle and those of 
the inferior tibio-fibular joint, but is relaxed and 
loose both in front and behind to such a degree as to 
permit, during flexion and extension, transverse 
creases or folds to form. Anteriorly the membrane 
extends a short distance upon the neck of the astra- 
galus, from which it is separated by a small quantity 
of fat. This prolongation is divided into a number of 
imperfectly defined compartments by a series of 
vertically disposed septa. Superiorly the membrane 
lies between the tibia and the fibula to consti- 
tute the inferior tibio-fibular joint, as already seen. 
The outer surface of the membrane is in association 
anteriorly with the tendons of the extensors of the toes, 
and posteriorly with the tendons of the Gastrocnemius 
and the Plantaris muscles. The tendon of the last- 
named muscle may be said to exercise a tensile power 
over the membrane. The synovial fringes which are 
so conspicuous in the knee-joint are in the ankle ab- 
sent or insignificant. 
Movements.-The movements of the ankle-joint 
are in the main those of the ginglymoid joints. 
When the weight of the body is borne directly upon 
the astragalus, as in standing erect, the astragalus acts 
as a continuation of the shaft of the tibia, and serves 
to transmit the weight of the body to the arch of the 
foot. In this position the ligaments are relaxed, and 
the bone has a disposition to glide forward, since the 
upper articular surface is narrower behind than in 
front. This tendency is checked by the interosseous 
calcaneo-astragalar ligament, and by the impact of the 
astragalus against the scaphoid and the ligamentous 
bands uniting the last-named bones'to each other 
and to the bones of the leg. 
In extension, the anterior fifth of the superior astra- 
galar surface is exposed, as is the corresponding por- 
tion of the articular surface for the external malleolus. 
The movement is checked laterally by the anterior 
fascicle of the external lateral ligament, which, while 
becoming tense, assumes a direction obliquely down- 
ward and inward ; the middle and posterior fascicles 
are relaxed. The movement is checked niedianly by 
the anterior half of the deltoid ligament, while the 
posterior half is relaxed. 
In flexion, the narrowed posterior third of the 
EXPLANATION OF PLATE XLII 
Fig. 1. The ankle-joint, seen from behind. 
Fig. 2. The dorso-ventral section of the tarsus, showing 
synovial sacs. For the word "metacarpus" substitute 
"metatarsus." 
Fig. 3. The proximal end of tibia with the interarticular 
disks in position, and the tibial attachments of the 
crucial ligaments displayed. 
Fig. 4. The ligaments of the foot, seen from the median 
side. 
Fig. 5. The ligaments of the foot, seen from beneath. Pl-ATE XL II 
I Fig. 2 
Fig. 3 
Fig .1 
Fig. 4 
Pig. 5 
T Sinclair & Son Lith.. THE JOINTS AND LIGAMENTS OF THE FOOT. 
237 
superior articular surface is exposed, including a 
small portion of the surface of the outer malleolus, 
while ligaments relaxed in extension are now tense, 
and those previously tense are now relaxed. The 
movement is limited by the anterior lip of the tibial 
surface impinging against the neck of the astragalus. 
The ankle-joint in flexion is firmly fixed; rotation 
of the bones of the leg is transmitted to the astraga- 
lus ; and motion takes place between the astragalus 
and the calcaneo-scaphoid concavity. In extension a 
very slight lateral motion is perceptible between the 
tibia and the astragalus. 
The middle fascicle of the external lateral ligament 
and the analogous band in the internal lateral liga- 
ment extending from the bones of the leg to the calca- 
neum-thus passing over the astragalus-have caused 
the last-named bone to be held in part as analogous 
to an interarticular disk between the bones of the leg 
on the one hand, and the calcaneum and the scaphoid 
on the other. 
It is interesting in this connection to recall the 
facility with which persons who have lost the astra- 
galus by excision of this bone after dislocation may 
yet walk with comparative ease. In such examples 
the distal ends of the bones of the leg move upon the 
calcaneo-scaphoid socket after the fashion of the head 
of the astragalus. 
In birds the astragalus is permanently anchylosed 
to the tibia, so that all the motions between the leg 
and the foot are such as occur in the human subject 
in flexion of the ankle between the leg and astraga- 
lus as one factor, and the remaining tarsal bones as 
the other. 
The attachments of the ligaments of the ankle- 
joint are so strong that severe wrenchings will 
more often result in the separation of the osseous 
surfaces in connection with the fibres of the ligaments 
than in rupture of the ligaments themselves. Mr. 
Callender, who first called attention to this subject, 
justly believes that the occurrence of such violence 
to the living bone is an efficient cause in prolonging 
the reparation of injuries incident to a severely 
sprained ankle. 
In Pott's fracture, in which the fibula is fractured 
at the lower third, the ankle-joint is of necessity im- 
paired in its functions. The ginglymoid character of 
the joint is destroyed by the separation of the exter- 
nal malleolar surface from the astragalus. Dr. W. W. 
Keen has observed that in this fracture the astragalus 
can be pushed away from its contact against the in- 
ternal malleolus with ease. 
In talipes equinus the anterior portions of the lateral 
ligaments are lengthened, while the posterior are 
shortened. 
Rarely a bursa, lying beneath the internal lateral 
ligament, communicates with this joint, or with the 
joint between the head of the astragalus and the sca- 
phoid bone and the calcaneum. 
Nerves.-The ankle receives posteriorly a nerve 
from the posterior tibial nerve, anteriorly one from 
the anterior tibial. 
Arteries.-These are derived from the malleolar 
branches of the anterior tibial and the peroneal 
arteries. 
The Joints and Ligaments of the Foot. 
The bones of the foot are adapted to one another 
by concave, convex, or flat surfaces, and are held 
together by ligaments of great strength and variety. 
When the weight of the body is borne by the foot, 
the astragalus is fixed between the malleoli, and func- 
tionally acts in this position as a continuation of the 
tibia in transferring the weight to the remaining 
tarsal bones. 
As a result of this weight there is a disposition on 
the part of the bones of the tarsus to be pressed down- 
ward, the arches of the foot to be destroyed, and the 
metatarsal bones to spread laterally. Both joint- 
surfaces and the ligaments tend by their disposition 
to overcome this tendency, which is still further 
resisted by the lines of traction of muscles. 
The ligaments are all stouter and more varied on 
the plantar surface and in the interosseous spaces than 
on the dorsal surface. 
The following classification will be followed in this 
connection:- 
The Joints and Ligaments of the Tarsus. 
The Joints and Ligaments between the Tarsus and 
the Metatarsus. 
The Inter Metatarsal Joints and Ligaments. 
The Joints and Ligaments between the Metatarsus 
and the Phalanges. 
The Inter-Phalangeal Joints and Ligaments. 
THE JOINTS AND LIGAMENTS OF THE TARSUS. 
The joints of the tarsus (figs. 2, 8, 5, Plate XLII.) 
are the following:- 
The joint between the astragalus and the calca- 
neum posterior to the interosseous ligament. It pos- 
sesses a separate synovial membrane and capsule. 
The joint between the astragalus, and the calcaneum 
in advance of the interosseous ligament, together with 238 
TILE JOINTS AND THE LIGAMENTS. 
the scaphoid bone and the inferior calcaneo-scaphoid 
ligament. This extensive and important surface is 
inclosed by a common synovial membrane. 
The joint between the calcaneum and the cuboid 
bone. 
The joint between the scaphoid bone and the three 
cuneiforms is concave proximally and convex dis- 
tally. The lateral facets between the cuneiform bones 
and the cuboid are sufficiently indicated in the descrip- 
tion of these bones. 
The chief ligaments of the tarsus are- 
The External Astragalo-Calcaneal. 
The Internal Astragalo-Calcaneal. 
The Interosseous. 
The Superior Calcanco-Cuboid. 
The Internal Calcaneo-Cuboid. 
The Inferior Calcaneo-Cuboid. 
The Superior Calcaneo-Scaphoid. 
The Inferior Calcaneo-Scaphoid. 
The Astragalo-Scaphoid. 
The Scaphoido-Cuneiform. 
The Scaphoido-Cuboid. 
The External Astragalo-Calcaneal Ligament.- 
This is a small fasciculus attached above to the astra- 
galus, and below is inserted into the calcaneum along- 
side of the middle fasciculus of the external lateral 
ligament of the ankle-joint, with which it is often in 
part confounded. 
The Internal Astragalo-Calcaneal Ligament is 
short, slender, and membranous, and is attached above 
to the astragalus at the border of the groove for the 
Flexor Longus Pollicis, and below to the calcaneum. 
The Interosseous Ligament (middle astragalo-calca- 
neal).-This powerful structure occupies the canal 
between the astragalus and the calcaneum. It is nar- 
row and short medianly, but widens as it approaches 
the lateral aspect of the foot, where it is superficial. 
As displayed within the sinus tarsi, the ligament is 
divided into two portions by a wide interval. The 
posterior portion (posterior interosseous) is a thin but 
stout fascicle that serves to strengthen the posterior 
of the two astragalo calcaneal joints. The anterior 
portion (anterior interosseous) is coarser and stouter 
than the preceding, and unites the superior portion of 
the anterior process of the calcaneum to a roughened 
surface on the neck of the astragalus. 
The Superior Calcaneo-Cuboid Ligament is a flat 
band extending from the upper and outer portion of 
the anterior border of the calcaneum to the corre- 
sponding part of the cuboid bone. It is entirely 
dorsal, and lies to the outer side of the Superior Cal- 
caneo-Scaphoid ligament. 
The Internal Calcaneo-Cuboid Ligament (interosse- 
ous) is a flat band of great strength attached proximally 
to the calcaneum, at the sinus tarsi directly within the 
anterior portion of the interosseous ligament. Distally 
it is attached to the cuboid bone at the interval 
between the proximal and the median surfaces. As 
a rule it is united at its calcaneal attachment with 
the Interosseous ligament, the two bands forming a 
V-shaped figure. 
The Inferior Calcaneo-Cuboid Ligament is the 
stoutest and largest ligament of the foot. It is com- 
posed of two separate fasciculi or bundles of fibres, 
which may be known as the greater and the lesser 
ligament. The greater ligament, thicker medianly 
than laterally, is attached proximally to the entire 
length of the under surface of the calcaneum in ad- 
vance of the tubercles. It extends forward in a 
straight line, and is attached distally to the under 
surface of the cuboid bone at the tubercle as far as 
the groove for the tendon of the Peroneus Longus 
muscle. The ligament strengthens the sheath of the 
last-named muscle, and sends prolongations to the 
bases of the fourth and fifth metatarsal bones.-The 
lesser ligament is attached distally to the anterior 
tubercle of the calcaneum, passes obliquely forward 
and inward, and is concealed in part by the greater 
ligament, to be attached to the cuboid bone at the 
proximo-median angle. 
The Superior Calcaneo Scaphoid Ligament (external 
calcaneo-scaphoid, interosseous) extends from the 
anterior portion of the calcaneum at the place of 
origin of the internal calcaneo-cuboid ligament. It is 
a stout, flat, well-defined band - its superior border 
lying on the dorsal, and its inferior on the plantar 
surface-and extends obliquely forward and inward, 
to be attached to the outer side of the scaphoid bone. 
Inferiorly it is in contact with the small cartilaginous 
surface at the medio-plantar angle of the cuboid bone. 
The Inferior Calcaneo-Scaphoid Ligament extends 
as a broad, somewhat radiated structure from the 
median surface of the calcaneum at the interval 
between the anterior tubercle and the sustentaculum 
tali, as well as the median borders of the facet of 
articulation with the astragalus. It passes forward 
and inward to be attached to the under surface of the 
scaphoid bone. Its fibres are continuous proximally 
with those of the deltoid ligament, and distally in part 
with the cuboidal attachment of the lesser calcaneo- 
cuboidal ligament. At its upper portion it is thicker 
than elsewhere, and depressed for the accommodation 
of the tendon of the Tibialis Posticus muscle which 
strengthens the ligament, and indirectly supports the THE JOINTS AND LIGAMENTS OF THE FOOT. 
239 
head of the astragalus. Viewed from above, in a foot 
from which the astragalus has been removed, the in- 
ferior calcaneo-scaphoid ligament is seen to form the 
median and basal aspect of a socket of which the 
calcaneum and the scaphoid bone form the remaining 
parts. The ligament is of great strength, and aids in 
breaking the shock attending the abrupt transfer of the 
weight of the body through the astragalus upon the foot. 
The Astragalo-Scaphoid Ligament is a broad, fine- 
textured, capsule-like membrane extending from the 
dorsum of the neck of the astragalus forward over 
the prominence of the head of the same bone to the 
dorsum of the scaphoid bone, some of its fibres pass- 
ing to the second cuneiform. It partly overlies the 
scaphoido-cuneiform ligaments. 
The Scaphoido-Cuneiform ligaments superiorly are 
distinct flat slips passing from the scaphoid bone to the 
cuneiform bones. They are best developed on the 
median border of the foot when the scaphoid and the 
first cuneiform bone are united. Inferiorly the single 
stout scaphoido-cuneiform ligament is attached proxi- 
mally to the tubercle of the scaphoid, and passes in a 
radiate manner thence to the cuneiform bones. 
The Scaphoido-Cuboidal Ligaments present a supe- 
rior, an inferior, and an interosseous fascicle. The 
superior fascicle is much shorter than the inferior. It 
passes from the upper and the median part of the 
superior surface of the cuboid to the scaphoid bone. 
The inferior fascicle-one of the most conspicuous of 
the plantar ligaments-passes in the form of a flat- 
tened cord from the tuberosity of the scaphoid bone 
forward and outward to the cuboid bone. The inter- 
osseous fascicle occupies the deep excavation between 
the scaphoid and the cuboid bones, and is also attached 
to the third cuneiform. 
The three cuneiform bones are held together by 
short, peripheral, and interosseous ligamentous bands, 
as in the union of the third cuneiform with the cuboid. 
They do not demand extended description. 
Remarks.-The actions of the ligaments of the 
tarsus can be best studied by dividing them under 
the following heads :- 
(1) The movement of the astragalus on the cal- 
caneum and the scaphoid bone. 
(2) The movement of the calcaneum on the cuboid. 
(3) The movement of the medio-tarsal joint. 
(1) The weight of the body when thrown upon the 
foot tends to rotate the astragalus on the fixed calca- 
neum inward ; the head of the first-named bone moves 
inward and downward on the line of motion afforded 
by the posterior calcaneo-astragalar articulation. The 
action is checked by all the ligaments of the ankle- 
joint, the astragalo-calcaneal, the anterior portion of 
the interosseous (now horizontal), the superior and 
the inferior calcaneo-scaphoid which become tense. 
The astragalo-scaphoid ligament and the posterior 
portion of the interosseous ligament are relaxed. 
When the weight of the body is removed from the 
foot, as in the supine position, the posterior calcaneo- 
astragalar articulation is at rest, and the surfaces in 
part separated. The posterior portion of the inter- 
osseous ligament and the astragalo-scaphoid are tense, 
while the remaining ligaments are relaxed. The 
head of the astragalus at the same time forms a pro- 
minence on the dorsum of the foot. 
In the affection ordinarily called "sprained ankle" 
the ligaments of the ankle and the tarsal ligaments, 
save two only, are subjected to over-strain. The 
posterior calcaneo-scaphoid joint suffers more than 
any other portion of the tarsus, and develops an ex- 
quisitely tender spot answering to pressure over the 
sinus tarsi. Should the ligaments holding the astra- 
galus to the calcaneum and the calcaneum to the 
scaphoid bone yield, dislocation of the astragalus 
forward and inward is effected. 
(2) When the weight of the body is borne on the 
foot, as in the erect position, the nearly flat joint be- 
tween the calcaneum and the cuboid bone becomes 
entirely engaged. The inferior calcaneo-cuboid liga- 
ment becomes tense, while the superior ligaments be- 
come relaxed.-In the supine position the joint is at 
rest, and the surfaces tend to separate from one an- 
other. The inferior ligament is now relaxed, and 
the superior is tense. The astragalo-scaphoid, and 
both the dorsal calcaneo-cuboid ligaments might now 
be termed suspensory to the foot beyond the medio- 
tarsal line.-The prolonged retention of the foot in 
the position last described constitutes "foot-drop," 
a complication which is liable to occur in bed-ridden 
patients when the foot is kept for a long time with- 
out support to the medio-tarsal joint. Talipes equi- 
nus is a variety of "foot-drop." 
(3) The action of the medio-tarsal joint is one of 
torsion about the internal calcaneo-cuboid and the 
calcaneo-scaphoid ligaments. The torsion is deter- 
mined by muscles inserted distally to the joint-line. 
The Tibialis Anticus and the Tibialis Posticus act on 
the stout median border from the inner side, and turn 
the sole downward and inward, while the Peroneus 
Longus, acting on the same line from the outer side, 
turns the sole downward and outward.-Inward rota- 
tion of the astragalus tends to carry the foot inward 
-an action antagonized by the Peroneus Longus. 240 
THE JOINTS AND THE LIGAMENTS. 
When this muscle contracts, while the weight of the 
body is borne upon the foot, the check ligaments to 
the motion of the astragalus are made more tense.- 
The line of motion in torsion is determined at the 
medio-tarsal joint. When outward torsion is effected 
without weight being thrown on the foot, the foot is 
said to be pronated. In talipes valgus the pronation 
is extreme and persistent. In pronation the motion 
is checked by the superior calcaneo-scaphoid and 
astragalo-scaphoid ligaments. In females pronation 
is more pronounced than in males. In the motion 
opposite to the above the foot is said to be supinated. 
The superior calcaneo-scaphoid ligament is relaxed, 
and the internal calcaneo-cuboid is tense. Supina- 
tion is the congenital position of the foot. Extreme 
and fixed supination constitutes talipes varus. 
The medio-tarsal joint corresponds to nearly a trans- 
verse line, so that the foot can here be easily disar- 
ticulated. 
THE JOINTS AND THE LIGAMENTS BETWEEN THE TARSUS 
AND THE METATARSUS. 
The joints between the tarsus and the metatarsus 
are three in number :- 
One between the first cuneiform bone and the 
corresponding metatarsal bone. It is convex proxi- 
mally, concave distally, and longer from the dorsal 
to the plantar surface than from side to side. 
One between the second and the third cuneiform 
bones and the corresponding metatarsal bones. It is 
slightly convex proximally, concave distally at its 
median, but nearly flat at its lateral half. 
One between the cuboid bones and the fourth and 
fifth metatarsal bones. It is concave proximally and 
convex distally. 
Each of the above joints is furnished with a sepa- 
rate synovial sac. The synovial membranes of the 
tarso-metatarsal articulation are arranged as follows: 
one sac intervenes between the first cuneiform bone 
and the corresponding metatarsal bone. The second 
is a large sac between the second and the third cunei- 
form bones and the cuboid above, and the outer four 
metatarsal bones below, between the heads of which it 
may send small prolongations. 
The middle and external cuneiform, and the sec- 
ond and third metatarsal bones may possess a sac sepa- 
rate from that between the cuboid and the outer two 
metatarsal bones, as seen in fig. 2, Plate XLII. 
The ligaments between the tarsus and the meta- 
tarsus are- 
The Superior Ligaments. 
The Inferior Ligaments. 
The Interosseous Ligaments. 
The Superior (dorsal) Ligaments are seven in num- 
ber. The most internal of these unites the first 
cuneiform bone to the first metatarsal. The three 
following unite the first, the second, and the third 
cuneiform bone to the second metatarsal bone ; a sepa- 
rate ligament passes from the third cuneiform bone 
to the third metatarsal. Fascicles pass from the cuboid 
bone to the fourth and the fifth metatarsal bones. 
The Inferior (plantar) Ligaments. The crowded 
condition of the narrowed inferior borders of the 
second and the third cuneiform bones, together with the 
corresponding border of the cuboid, renders the inferior 
ligament less regular than the superior, but it follows 
the rule of the ligaments of the foot elsewhere in 
being more powerful. Those uniting the relatively 
enormous surfaces of the first cuneiform and the first 
metatarsal, as well as those of the adjoining bones, 
are stouter than the remaining ligaments. In addition 
to the above, bands of variable size pass from the first 
cuneiform to the second and the third metatarsals. 
The region is protected by the tendons of the Tibi- 
alis Posticus and the Peroneus Longus muscles. 
The ligaments passing from between the bones at 
the cuboid-metatarsal joint are unimportant. The 
most striking is a band of inconstant size extending 
between the bases of the third and fourth metatarsal 
bones under the cuboid bone. 
The Interosseous Ligaments are two in number-the 
internal and the external. The internal, the longer 
of the two, extends from the first cuneiform bone to 
the opposite side of the second metatarsal close to the 
articular facet. The external extends between the 
outer side of the third cuneiform bone to the inner 
side of the fourth metatarsal. A slip of this band 
also passes to its own metatarsal bone. 
THE INTER-METATARSAL JOINTS AND LIGAMENTS. 
The metatarsal bones are connected with one an- 
other at both the distal and the proximal ends. 
The ligaments, as in the case of the tarso-metatarsal, 
are divided into- 
The Superior Ligaments. 
The Inferior Ligaments. 
The Interosseous Ligaments. 
The Transverse Ligaments. 
The Superior (dorsal) Ligaments are delicate bands 
directed transversely. The most internal pass from 
the first to the second bones; the middle from the THE JOINTS AND LIGAMENTS OF THE FOOT. 
241 
third to the fourth; and the external from the fourth 
to the fifth. 
The Inferior (plantar) Ligaments are stronger than 
the above-named, but resemble them in their general 
plan. 
The Interosseous Ligaments are placed between the 
opposed surfaces of the metatarsal bones near the 
proximal extremities. They are weaker than are the 
ligaments of the tarsus of the same name. 
The Transverse Ligaments are names given to 
loosely fasciculated bands uniting the distal ends of 
the metatarsal bones. 
THE JOINTS AND LIGAMENTS BETWEEN THE META- 
TARSUS AND THE PHALANGES. 
These articulations furnish a convex proximal sur- 
face well advanced on the plantar region, and a con- 
cave distal surface. In the first joint this surface is 
as broad as high. The motion of flexion is impaired 
by the position of the sesamoid bones on the plantar 
aspect.-The proximal surfaces of the remaining joints 
are compressed laterally.-Each joint is inclosed by 
a synovial sac and capsule, which are weaker above 
than elsewhere, and which are greatly strengthened 
on the sides by cord-like lateral ligaments passing ob- 
liquely downward and forward. They are thick in- 
feriorly where they are supported by the tendons of 
the flexors of the toes. 
THE INTER-PHALANGEAL JOINTS AND LIGAMENTS. 
The joint surfaces of these articulations are convex 
proximally, and concave distally, with the exception 
of the first inter-phalangeal, where the proximal 
surface is so far depressed in the centre as to become 
concave. The joints are well protected on all sides 
by the synovial sacs and capsules, the latter being 
strengthened at the sides by the lateral ligaments. 
Beneath, each joint is supported by a fibrous pad or 
plate and the underlying tendons of the flexors of the 
toes. In necrosis of the phalanges, the inferior 
fibrous pads above mentioned will oftentimes retain 
the bones in connection with the living parts after all 
other bands have been destroyed. 
Remarks.- The great strength of the first toe 
enables the ballet-dancer to sustain upon the inter- 
phalangeal joint the entire weight of the body.- 
Owing to the disposition of the first metatarso-pha- 
langeal joint, flexion is here imperfectly performed.- 
This joint is frequently deformed by acquired deflec- 
tion of the first phalanx outward, and is often the 
seat of an inflammation communicated to it by a 
bursa situated above and to its inner side. 
The Nerves of the metatarso-phalangeal articula- 
tions are derived from the external plantar. Those 
of the inter-phalangeal joints are derived from the 
internal plantar. PROSPECTUS 
A SYSTEM OF HUMAN ANATOMY, 
INCLUDING ITS 
MEDICAL AND SURGICAL RELATIONS. 
-BY- 
HARRISON ALLEN, M. D., 
PROFESSOR OF PHYSIOLOGY IN THE UNIVERSITY OF PENNSYLVANIA, ETC., ETC. 
WITH 
A CHAPTER ON HISTOLOGY, 
-BY- 
E. O. SHAKESPEARE, M. D., 
OPHTHALMOLOGIST TO THE PHILADELPHIA HOSPITAL. 
To be completed in Six Sections, containing about ppo pages of letter-press, illustrated with 380 figures on 109 plates, many of which are 
beaut fully colored. The drawings by Hermann Faber, from dissections by the Author. Also, 230 woodcuts in the text. 
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Section I. HISTOLOGY. Section IV. ARTERIES, VEINS AND LYMPHATICS. 
" II. BONES AND JOINTS. " V. NERVOUS SYSTEM. 
" III. MUSCLES AND FASCIAE. " VI. ORGANS OF SENSE, OF DIGESTION AND GENITO-URINARY ORGANS. 
The plan and scope of the work may be gathered from the following brief extract from the introduction. 
"It is the design of this book to present the facts of human anatomy in the manner best suited to the requirements of the student 
md practitioner of medicine. The author believes that such a book is needed, inasmuch as no treatise, as far as he knows, contains, in 
iddition to the text descriptive of the subject, a systematic presentation of such anatomical facts as can be applied to practice. 
A book which will be at once accurate in statement and concise in terms; which will be an acceptable expression of the present 
state of the science of anatomy; which will exclude nothing that can be made applicable to the medical art, and which will thus 
embrace all of surgical importance, while omitting nothing of value to clinical medicine,-would appear to have an excuse for existence 
in a country where most surgeons are general practitioners, and where there are few general practitioners who have no interest 
in surgery." 
As a brief introduction to the essential features of the volume, attention is invited to the kinds of knowledge of the human 
body which the physician demands. 
First. An exact acquaintance with the form and construction of the organs of the body. But, inasmuch as an anatomical fact is 
of little use unless the range of application of the fact is known, the due connection between the normal condition of the organs and their 
variations within the limits of health will receive proper attention, accordingly the typical description of each organ will be followed 
by a brief statement of such variations. 
Second. The physician demands a knowledge of the relations of the parts. This information it is necessary to possess in 
performing operations and in explaining signs and symptoms. 
Third. The physician needs some account of the uses of the organs. This subject overlaps physiological anatomy. That much 
only will be succinctly given as may be said properly to illustrate the subject from an anatomical point of view, and at the same time 
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Fourth. The physician must have a true conception of the nature and general behavior of morbid processes, and of the manner 
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"Among other matters, the book will be found to contain an elaborate description of the tissues; an account of the normal 
development of the body; a section on the nature and varieties of monstrosities; a section on the method of conducting post-mortem 
examinations; and a section on the study of the superficies of the body taken as a guide to the position of the deeper structures. These 
will appear in their appropriate places, duly subordinated to the design of presenting a text essentially anatomical." 
In the preparation of this elaborate work no pains have been spared. The illustrations of normal anatomy, with a few exceptions, 
are from original dissections, engraved on the stone, with the name of every part clearly drawn upon the figure after the manner of 
"Holden" and "Gray," and in every typographical detail it has been the effort of the publishers to render the volume worthy of the 
distinguished position anticipated for it. 
Each section will be enclosed in an individual portfolio, thus preserving all in a perfect condition in case it is subsequently 
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REYNOLDS' SYSTEM OF MEDICINE. Revised Edition. Now Ready. 
A SYSTEM OF MEDICINE. Edited by J. Russell Reynolds, M. I)., Professor of the Principles and Practice of Medicine in 
University College, London. With notes and additions by Henry Hartshorne, M. D., late Professor of Hygiene in the 
University of Pennsylvania. In three large and handsome royal octavo volumes, containing 3056 double-columned pages, with 
V7 illustrations Per volume, cloth, $5; leather, $6; half Russia, $6.50. Per set, cloth, $15; leather, $18; half Russia, $19.50. 
The labors of the American editor, Dr. Hartshorne, have been very conscientiously any other language, for that matter, which equals much less excels, Reynolds' System 
performed and his judicious notes distributed throughout, afford abundant evidence of the Each volume contains a complete index a feature whwh hose who may have encyclop^du 
thoroughness of the revision at his hands. In conclusion, we take pleasure in commending works of medicine not containing this index can fully appreciate.-Mc^an Mechau 
this work to our readers, feeling confident that it will not only become standard, but from News, June 10, 1880 t. r ,. . . n _ 
its containing just that information which the busy practitioner frequently finds himself in We regard this the finest work on the practice of medicine in the English language. 111 
need of from its completeness, its fulness of detail, and its excellence, it will be justly ap- fact, we do not think it has its superior in any language in the world. Combining, as H 
preciated bv the entire profession on this continent.-^™ Practitioner, April, 1880. does, a complete history of diseases a thorough account of their pathology a full description 
For conciseness and comprehensiveness in the treatment of all the subjects embraced of therapeutics, and a minute detail of treatment, etc., it embodies all that a practitione. 
under the head of " Practice of Medicine," there is no work in the English language, or in can ^.-Cincinnati Medical Times, August 1880. 
HOLMES' SYSTEM OF SURGERY. Americanized. Just Ready. 
A SYSTEM OF SURGERY, THEORETICAL AND PRACTICAL. In Treatises by Various Authors. Edited by Timothy 
Holmes, M. A., Surgeon and Lecturer on Surgery at St. George's Hospital, London. American edition, thoroughly revised 
and much enlarged, by John H. Packard, M. D., Surgeon to the Episcopal and St. Joseph's Hospitals, Philadelphia, assisted 
by a corps of thirty-three of the most eminent surgeons of America. In three large and very handsome royal octavo volume; 
containing 3137 double-columned pages, with 979 illustrations on wood, and 13 lithographic plates, beautifully colored. Pei 
volume, cloth, $6; leather, $7; half Russia, raised bands, $7.50. Per set, cloth, $18; leather, $21; half Russia, raised bands, $22.50. 
Representing originally the most advanced school of British surgery, it has been supple- sufficient guarantee that the work has not only been brought fully up to date, but also tha 
mented, through the labors of its editor, by what is latest and best in the surgery of America. it has been accomplished in this large, thorough and scientific spirit, which characterize 
It may therefore be regarded as embodying whatever is of established value in this depart- the contributions to the original edition.-Canada Journal of Medical Science, Nov. 1881. 
ment 'of our art. No°surgeon who proposes to keep abreast with his rivals can afford to be The elegant American revision of this justly celebrated work, will give to the America! 
without it.-American Practitioner, April, 1882. practitioners, a corresponding collaboration of surgical lore, to that they already have ii 
It is a subject for congratulation that the idea of an American edition, incorporating possessing the volumes of Reynolds' System of Medicine, and with the two works, th, 
all recently acquired knowledge and experience, should have been conceived and its fortunate possessor has a most complete library on Practical Medicine and Surgery- 
execution "entrusted to such able hands as Packard's. The names of coadjutors afford a Braithwaite's Retrospect and Quarterly Epitome of Pract. Med. and Surg., Sept. 1881. 
PERIODICALS. 
SUBSCRIPTION RATES, POSTAGE PAID. 
The Medical News (published every Saturday) in advance .................. $5.0 
The American Journal of the Medical Sciences (quarterly) in advance $5.0 
COMMUTATION RATES. 
The Medical News I . , 
... „ > m advance, 80.0 
The American Journal of the Medical Sciences ................ J 
THE AMERICAN JOURNAL OF THE MEDICAL SCIENCES. 
I. MINIS HAYS, A. M., M. D., EDITOR. 
For sixty-two years the American Journal has maintained its position in the front rank of medical literature, and to-day it stands alone as the only periodica 
in the English language capable of presenting extended and elaborate articles on every branch of medical science, the very class of contributions, in fact, in whic 
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for FIVE DOLLARS per annum, in advance. 
THE MEDICAL NEWS. 
A NATIONAL WEEKLY MEDICAL PERIODICAL, PUBLISHED EVERY SATURDAY, EACH NUMBER CONTAINING 
28 DOUBLE-COLUMNED QUARTO PAGES, EXCLUSIVE OF ADVERTISEMENTS. 
The Medical News aims to satisfy the demand of the profession for the most rapid possible conveyance of intelligence, in short, to be a professional new: 
paper. To this end it comprises the following departments: 1st. Clinical Lectures, by the ablest teachers of the day. 2nd. Original articles, of a brief an 
practical nature. 3rd. Hospital Notes, gleaned from the leading hospitals on both continents. 4th. The Progress of Medical Science, being extracts from th 
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