Dimensions of the Normal Pituitary 
Fossa or 5ella Turcica in the White 
and the Negro Races. 
HRDLICK A. 'Zs'f 
106 E. 71ST STREET, NEW YORK. Dimensions of the Normal Pitui= 
tary Fossa or Sella Turcica in 
the White and the Negro Races. 
An Anatomical Study of Fifty=seven Normal 
Skulls of White and Sixteen Normal Skulls 
of Colored Individuals 
WITH THREE PLATES. 
FROM THE PATHOLOGICAL INSTITUTE 
OF THE NEW YORK STATE HOSPITALS, 
AND THE DEPARTMENT OF ANATOMY, 
COLUMBIA UNIVERSITY, NEW YORK. 
ales hrdlicka, m. d. 
Reprint from the Archives of Neurology 
and Psychopathology, .V. I, No. 4, 1898. 
State Hospitals Press, Utica, N. Y. 
1899. 573.6 
DIMENSIONS OF THE NORMAL PITUITARY 
FOSSA OR SELLA TURCICA IN THE WHITE 
AND THE NEGRO RACES.—AN ANATOMICAL 
STUDY OF FIFTY-SEVEN NORMAL SKULLS OF 
WHITE AND SIXTEEN NORMAL SKULLS OF COL- 
ORED INDIVIDUALS. 
WITH THREE PLATES. 
Since it has been repeatedly demonstrated that marked 
enlargements of the pituitary body are of a pathogno- 
monic nature, it becomes desirable to learn the normal 
dimensions of the hypophysis, and also its normal range 
of variations in size. 
The pituitary gland itself is not well adapted for accu- 
rate measurements.* The organ is small, very yielding, 
and does not present any positive landmarks for measur- 
ing. Furthermore, the gland is frequently injured in ex- 
traction. Under these circumstances we find an equally 
good if not much better subject for hypophyseal measure- 
ments in the enveloping bony fossa. 
We have thought that measurements of the fossa 
might be of value in identifying and differentiating the 
skeletons of acromegalia and gigantism, osteo-arthropathie 
hypertrophiante, etc., and also be of some anthropologic 
value in the differentiation of races. We must, however, 
* Zander records the variations in the diameters of the normal hypophysis as 
follows: Sagittal diameter, 6.0-10.5 mm.; frontal, 10.0-14.5 mm.; vertical, 5.0-9.75 
mm. According to Schonemann, Boyce and Beadles the average weight is 
0.6 gr. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
remember that the measurements of the fossa can 
never be an infallible index of the condition of the 
hypophysis. This may be comparatively little changed in 
size and still be the seat of hyperplasia which Brooks, in 
the preceding paper, shows to be the specific and definite 
causal process in acromegalia. It should not be expected 
that the early phases of hyperplasia can be detected by 
measurements either of the pituitary body or fossa. 
Microscopical examination of the hypophysis with especial 
reference to cytologic structural details affords the only 
means of determining these early cellular changes accom- 
panied by very slight enlargements of the hypophysis. 
These minor degrees of hyperplastic enlargement, al- 
though sufficient to initiate the train of acromegalic phe- 
nomena, might fall within the normal range of variations 
of the size of the hypophysis. On the other hand, en- 
largement of the pituitary fossa in the skeleton does not 
in every case indicate acromegalia, for Brooks shows that 
neoplasms of the hypophysis, although they may produce 
an enlargement of the fossa, have no causal relation to 
acromegalia. Thus we may expect to find enlargement of 
the pituitary fossa in non-acromegalic skeletons; and the 
earlier changes in acromegalic skeletons with but little if 
any enlargement of the fossa beyond the maximum of the 
normal range of variations. The latter condition, how- 
ever, would be of rare and exceptional occurrence. In 
the great majority of cases the acromegalic skeleton must 
show various degrees of unmistakable enlargement of 
the pituitary cavity due to the gradual absorption of bone 
about the hyperplastic or adenomatous gland. Since en- 
largements of the hypophysis, not associated with acrome- 
galia, are of very i;are occurrence, an enlarged pituitary 
fossa, especially when associated with noticeable changes DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
3 
in other parts of the skeleton, would convey at least a 
strong- suspicion of acromegalia. 
The pituitary fossa, or sella turcica, is not really a per- 
fect mould of the hypophysis, but the excess is small and 
also constant in a series of measurements. In addition to 
the hypophysis the cavity generally contains some alveo- 
lar tissue. This is especially true of the anterior part of 
the sella and of its opening. The connective tissue, 
however, is never present in such amount as to materially 
influence the dimensions of the fossa which correspond 
very closely to the volume of the pituitary body. When 
the hypophysis enlarges, the sella enlarges correspond- 
ingly, both in size and direction. An independent enlarge- 
ment of the sella or an independent increase of the con- 
nective tissue about the gland, has never been reported. 
Thus if we know both the average dimensions of the pitui- 
tary fossa and their possible variations in a normal state, 
any excess in the dimensions of the structure can be taken 
as a positive indication of an enlargement of the hypoph- 
ysis through neoplasm or hyperplasia. Knowing the 
normal measurements and their variations, we would also 
be enabled to judge as to the degree of enlargement of 
the organ. Both these possibilities, especially when taken 
in conjunction with abnormal features in other parts of 
the skeleton, may occasionally prove of great value in 
determining a differential diagnosis. 
Having access, through the courtesy of Prof. Hunting- 
ton, to the Anatomical Department of the School of 
Medicine of Columbia University, where are large num- 
bers of normal skulls, I undertook the task of ascertaining 
the average size and the limits of variations of the normal 
sella turcica. 
The study was made separately on skulls of white males 4 
DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
and females; I measured also a number of skulls of 
male and female negroes, and the data will be included 
for comparison. Only normal and adult specimens have 
been included; I have not been able to obtain a sufficient 
number of skulls of children and adolescents, and am 
unable to give satisfactory data of the variations of the 
pituitary fossa during the growth period. 
The first point in this investigation was to establish 
fixed landmarks, from which all subsequent measurements 
on different skulls could be taken. This proved to be 
quite difficult as the contours of the fossa are not well 
defined; the walls of both sides as well as the top being in- 
complete. The shape of the fossa differs from almost 
spheroidal, to obliquely or horizontally ellipsoidal; its 
walls and the immediate neighboring parts are subject to 
much variation in different skulls. 
The more or less rounded shape of the sella renders it fit 
for three measurements, namely, maximum length, width, 
and depth. To clearly indicate the landmarks for these 
three measurements,—landmarks which I decided upon 
only after numerous trials,—it will be necessary to review 
with some detail the anatomy of the fossa and adjacent 
bony structures. 
Proceeding from the posterior angles of the cribriform 
plate of the ethmoid, backward along the flat surface of 
the body of the sphenoid, the first distinct structure met 
with is a low, but in a large majority of cases, well defined 
transverse ridge. (Fig. i, a).* This bony elevation marks 
the anterior boundary of a slightly depressed space, which 
contains anteriorly a slight furrow, the optic groove, and 
behind this an elevation, the olivary eminence. The ex- 
tremities of the ridge surmount the optic foramina and 
* The indices in this description refer to Pigs, i and 2 of Plate I. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
5 
blend with the bases of the anterior clinoid processes. 
This ridge, which may advantageously be termed the 
anterior olivary ridge, is from 2.0 cm. to 3.0 cm. long, and 
usually about 1.2 cm. posterior to the posterior angles of 
the cribriform plate. 
The space which contains the optic groove and the 
olivary eminence is, as will be seen later, of a certain im- 
portance and deserves a close description. 
The optic groove is seldom perfect and frequently is very 
shallow or indistinct. The surface of the olivary eminence 
is more or less convex, both laterally and antero-pos- 
teriorly. The antero-posterior convexity varies consider- 
ably, in some cases the surface is almost flat, while in 
others the posterior part of the surface slopes down 
very abruptly. Laterally the olivary eminence is bounded 
by the carotid semi-foramina. Posteriorly, the boundary 
of the eminence is formed by another distinct and almost 
constant bony elevation, which terminates on each side 
in a short, sharp point, termed the second or middle 
clinoid process. This second, or posterior olivary ridge, 
forms the anterior border of the pituitary fossa, and its 
centre (Fig. 1, b), is our first landmark, namely, the 
anterior point from which we take the antero-posterior 
diameter, or the length, of the sella turcica. 
The space between the anterior and posterior olivary 
ridges is bounded laterally by the mesial surfaces of 
the anterior clinoid processes. If well formed, these 
processes proceed from the extremities of the anterior 
olivary ridge, in front and outside of the optic foramina. 
Their mesial lines converge (in a few skulls they diverge) 
a little in their distal half. Their external lines, which 
are continuous with the posterior borders of the lesser 
wings of the sphenoid, converge gradually throughout 6 
DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
their whole length. These two lines, i. e., the inner and 
outer borders of the anterior clinoid process, meet in a 
sharp or blunt point, marking the free extremity of the 
process. These extremities are usually about opposite 
the middle of the sella turcica; in some skulls they ter- 
minate somewhat more anteriorly. They can be utilized, 
as will be seen later, for landmarks of a certain 
measurement. 
Progressing still backward from the posterior olivary 
ridge, we meet the sella turcica itself, which presents for 
examination an anterior and posterior wall, and a base; 
the sides and roof are deficient. 
Holding the skull in its standard position, (i. e., horizon- 
tal or alveolo-condylian line of Broca), we see that the 
anterior wall of the pituitary fossa is not vertical, but 
slopes somewhat downwards and backwards. From side 
to side it is flattened, or slightly concave, especially at the 
base. The borders of this anterior wall are very blunt 
and convex, sloping away gradually into the carotid de- 
pressions on their exterior. 
The base of the pituitary fossa is generally somewhat 
narrower than the anterior wall, although the gradual out- 
ward slope may give the appearance of greater breadth. 
The direction of the base may be almost horizontal, but, 
most frequently, and especially in the female, it is inclined 
in varying degrees downward and backward. The sides 
slope to the considerably lower level of the carotid grooves. 
The surface of the base shows an oblong, more or less 
shallow but distinct depression, which lodges the lower 
part of the hypophysis. The borders of this depression 
are usually well marked, and as directly beyond them 
the parietes begin to slope downward, they offer us the 
only possible landmarks from which to measure the width DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
7 
of the pituitary fossa. For this measurement we choose 
the highest points on these borders, where they are 
most widely separated (Fig. i, e e). Occasionally, unusual 
breadth and indefiniteness of these borders may make 
selection of the proper points somewhat difficult, but such 
instances are exceptional, and with some care the proper 
measure can generally be determined. The width thus 
obtained will be but little less than the maximum width 
of the hypophysis but sufficiently accurate for all prac- 
tical purposes. 
Posteriorly, the pituitary fossa is surmounted by a high, 
flat process of bone, the dorsum sellae. This bony lamella 
rises from above the spheno-occipital suture, and in the 
adult skull is directly continuous with the basilar pro- 
cess of the occipital bone. It is inclined somewhat for- 
ward, and in some cases is narrower at the base than at 
the top. The top of the lamella is free, and the margins 
irregular and thickened. The superior border presents a 
more or less marked notch in the middle, and terminates 
on each side in a small conical body, the third or posterior 
clinoid process. Posteriorly, the dorsum sellae is rough 
and flat, while the lower part is slightly concave. This 
concavity is continuous with that of the basilar process, 
together forming a distinct, broad groove. Anteriorly 
(ventrally) the dorsum is in most cases but slightly con- 
cave ; however, in a certain percentage of cases it shows 
a pronounced rounded depression. 
For our purpose of measuring the sella turcica, the 
most interesting part of the dorsum sellae is the middle of 
the anterior edge of its upper border (Fig. i, c). This 
point is the only suitable posterior landmark for the meas- 
urement of the antero-posterior diameter of the fossa, the 
anterior landmark being, as already stated, the middle of 
the posterior olivary ridge (Fig. i, b). 8 
DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
The notch in the centre of the upper border of the 
dorsum sellse, as well as the occasional marked depression 
on its ventral surface, are indications of an original defi- 
ciency in the lamella and we find such a deficiency in 
varying degrees in lower animals. Occasionally (in man), 
the notch is unusually deep, and in such a case our poste- 
rior landmark for the length measure of the fossa must be 
shifted a little on the anterior edge of the dorsum to one or 
the other side of the notch. Such a shifting of one land- 
mark of the measure will not cause any appreciable 
change in the value of this measurement. The thickness 
of the upper border of the dorsum sellse should never be 
included in this measurement; it is very uneven in 
different skulls. 
The lateral and the antero-posterior diameters obtained, 
it remains for us to measure the depth of the fossa. The 
best method, I find, for taking this measure is as follows, 
lay a thin, narrow piece of steel or wood over the fossa 
from before backwards: its anterior end should rest 
on the top of the olivary eminence, and its posterior 
part should lie over the notch in the superior border of 
the dorsum sellae (Fig. 2, c). From the under surface of 
this improvised roof, when in the proper position, we 
secure a perpendicular to the deepest depression in the 
base of the pituitary fossa; the length of this line is the 
measurement of the depth of the fossa (Fig. 2, x to f). 
This perpendicular measure is best obtained by a small, 
graduated steel rod; with a little more care it may be 
accurately determined by a delicate compass. 
The most simple and practical way to make this measure 
is to use a piece of an old steel tape measure for the 
horizontal lamella or roof, and a tooth-pick for the vertical 
rod, pressing the latter, when in the proper position, a DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
9 
little against the sharp edge of the former, and then 
measuring on the tooth-pick the height of the indentation. 
The depth thus obtained is generally a little too great, 
but the excess is seldom more than i mm. and is unavoid- 
able. This variation is not corrected in our calculations. 
Theoretically, the proper anterior landmark in meas- 
uring the depth of the sella would be the posterior olivary 
ridge. (Fig. 2, b). This ridge, however, though fully 
satisfactory for the length measurement, is in different 
skulls situated at such varying planes of height, that it can 
not be assumed to represent in every case the real height 
of the hypophysis and can not be well utilized for the 
depth measure. The point of the olivary eminence, 
though a little too high, is a much more stable landmark. 
Furthermore, the measurement from this point is very 
much easier to take than from the posterior olivary ridge. 
The three principal measurements of the pituitary fossa 
obtained, we may consider two secondary ones. When we 
look at the region of the fossa from above, we notice that 
the anterior olivary ridge, the inner surface of the first 
or anterior clinoids, and the anterior line of the superior 
border of the dorsum sellae, form an interrupted bony ring, 
situated somewhat above (superior to) the fossa itself. In 
some skulls this ring is completed through the union of the 
first and the third clinoid processes. This ring is capable 
of two measurements, the length and the width. The 
width of the ring is the distance between the points of 
the anterior clinoids. The antero-posterior diameter 
of the ring can be obtained from the centre of the ante- 
rior olivary ridge to the centre of the superior border of 
the dorsum sellse. (Fig. 2, a to These measurements, 
however, are of little medical or anatomical importance. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
Having discussed in detail the conformation and the 
manner of obtaining the measures of the pituitary fossa, I 
can now give the results of the measurements. 
In the manner described above the sellse were measured 
in four series of skulls of various white races and in two 
other series of American negroes. The number of speci- 
mens in the first two series I consider sufficient for the 
establishment of a correct average of measurements, and 
the scales of normal variations are undoubtedly almost 
complete. The number of the negro skulls is somewhat 
small; nevertheless they are sufficient to indicate in a gross 
way the essential similarities and differences of measure- 
ment in the pituitary fossae of the white and black families. 
I should expect these differences to be more marked in 
pure African negroes, in whom all chances of admixture 
of white blood could be excluded. 
I did not stop at the crude principal measurements of the 
fossa, but have endeavored to establish certain compari- 
sons, in order to control the simple measurements. 
It would seem reasonable to assume that the volume 
of the pituitary fossa would bear some relation to the 
capacity of the skull. The volume or capacity of the 
skull increases in certain proportion with the size and 
particularly with the height of the body, and the pituitary 
fossa, being a part of the cavity of the skull, might be ex- 
pected to enlarge correspondingly. 
Thus we would expect to find a perceptibly larger 
pituitary fossa in the male skulls as compared with 
female skulls and a smaller fossa in smaller people of 
either sex. 
But it is quite difficult to obtain the correct cubical vol- 
ume of the pituitary fossa, and in most of the cases I 
examined, a previous opening of the skull made a measure DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
of the capacity of the skull impossible. It was neces- 
sary, then, to look for the most satisfactory substitute 
for capacity. 
Of head measurements no single one furnishes a relia- 
ble index of the size of the cranium. The most satis- 
factory substitute for skull capacity is expressed by the 
maximum circumference of the cranial vault, and we have 
utilized this measure in place of that of cranial capacity. 
In the place of the capacity of the pituitary fossa, we 
can utilize any of its three principal diameters. I found it 
far more satisfactory, however, to secure an average of 
the length, width and depth of the fossa, and compare 
this average with the circumference of the skull. This 
average constitutes a module, which is a purely mathe- 
matical, but none the less practical, substitute for the real 
capacity measure of the fossa, and corresponds to the skull 
module of Schmidt,* i. e., 
Length -f- Width -J- Height of Skull, Max. 
3 
By comparing the module of the pituitary fossa with the 
maximum circumference of the same skull, we obtain a 
number which clearly expresses the size relation of the 
two measures, and this is sufficient for our purpose. 
To obtain this number, we first state the module of the 
pituitary fossa, according to the formula of Schmidt : 
Length -f- Width + Depth 
Multiply this by 1000 and divide the result by the 
circumference of skull expressed in centimetres. The 
module of the fossa is thus expressed in thousandths of 
the circumference measurement of the skull. 
3 
♦This formula has proven very valuable to the anthropologist 12 
DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
We might choose the percentage instead of the per 
thousand, but the resulting number would be very small 
and inconvenient. 
I think that the measurements of the pituitary fossae 
of the four series of skulls mentioned should be given in 
detail. If so stated, the reader who may wish to give a 
closer attention to the subject will find himself supplied 
with ample data. These detail measures, however, can 
well be placed in an appendix, not to disturb the continuity 
of the paper. In this place I will state only the averages 
and the variations of the measures for each group. 
The Length, or Antero-Posterior Diameter of the Pituitary 
Fossa. (See Plate II, Fig. 1). 
White Male. 
White Female. 
Negro Male. 
Negro Female. 
Averages: 
i. n cm. 
1.00 cm. 
r.09 cm. 
1.06 cm. 
Variations: 
0.75-1.45cm. 0.75-1.30cm. 
0.85-1.25 cm. 0.80-1.40 cm. 
In the cases of the white male and white female, where 
the number of skulls examined is large, the variations 
can be expressed to advantage graphically by columns or 
curves. (See Plate II, Fig. i): 
The wide variation of the length measure is striking. 
The same thing will be observed more or less with the 
other measures of the pituitary fossa. The maximum of 
variation reaches with some of the measures fully ioo per 
cent. Nevertheless, the majority of measurements of 
each series, group themselves around the average and 
the extremes must be considered as exceptions. 
The average length of the fossa does not differ greatly 
in the four series. There is a decided difference in the 
dimensions of the white male and white female, the 
latter averaging about i mm. shorter. There is a similar 
but much smaller difference between the sexes in the 
negro. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
13 
The scale of variations appears to be much smaller in 
the negro male than in the white male.* 
No very appreciable or stable differences in the measure- 
ments could be found corresponding to brachy- or dolicho- 
cephaly. The average length of the fossa, however, is 
less in the very short than in the very long skulls. This 
condition is corroborated by the two maxima around the 
averages shown in the columns which represent the 
length variations. (Plate II, Fig. 1). The other two 
measures of the fossa, namely, width and depth, do not 
show appreciable and stable differences relative to the 
shape of the skull. 
The Width, or Lateral Diameter of the Pituitary Fossa. 
(See Plate II, Fig. 2). 
White Male. 
White Female. 
Negro Male. 
Negro Female. 
Averages: 
1.15 cm. 
1.08 cm. 
1.05 cm. 
1.21 cm. 
Variations: 
0.70-1.50 cm. 
0.80-1.50 cm. 
0.95-1.40 cm. 
1.00-1.550x1. 
The differences in the four series are somewhat more 
pronounced in the width measurements than in the length. 
The average fossa in the white female is again appreciably 
smaller than that of the white male. Curiously, this differ- 
ence in the black is reversed; the breadth of the female 
fossa averaging 1.6 mm. greater than the male. This 
difference cannot be satisfactorily explained. Compari- 
sons of the fossae of the black and the white male show a 
lesser width as well as length in the latter. The scales 
of variation are again decidedly smaller in the black. 
Depth of the Pituitary Fossa. 
(See Plate II, Fig. 3). 
White Male. 
White Female. 
Negro Male. 
Negro Female. 
Averages: 
0.91 cm. 
0.94 cm. 
0.93 cm. 
0.91 cm. 
Variations: 
0.60-1.20 cm. 
0.60-1.30 cm. 
0.65-1.10 cm. 0.80-1.oocm. 
* This result may be partially due to the comparatively smaller number of 
negro male skulls represented in the figures. 14 
DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
The depth averages of these four groups are very- 
uniform. But while in the white it is the female, in the 
black it is the male whose average depth is somewhat 
greater. The scales of variation are again much smaller 
in the negro. 
According to these three measures, we see that the 
three dimensions of the fossa do not differ very much in 
their values. According to these figures the width of the 
fossa is its greatest, and the depth its least measure. 
The average of the fossae of the white male, is longer, 
broader, and slightly shallower than that of the white 
female, and also longer, broader and shallower than that of 
the male negro. This would tend to approach the types 
of the fossa in the negro male and the white female. 
Of the negro male and female the pituitary fossa of the 
male is the longer, narrower and deeper. 
These differences among the principal measures of the 
fossa can also be expressed by indices, but these present 
no special advantages. 
These three measures (length, width and depth) form 
the constituents of the module and this reflects their com- 
bined character. We find the module of the pituitary 
fossa for each of the four series of skulls to be as follows: 
White Male. 
White Female. 
Negro Male. 
Negro Female. 
Averages: 
1-057 
I.006 
1.056 
1.062 
Variations: 
.867-1.167 
.867-1.250 
.967-1.200 
.9OO-I.217 
The figures express clearly that the fossae of the males 
of the two human families are of almost identical vol- 
ume. The fossa of the white female is slightly smaller 
than that of the white male, while in the negro there is a 
very small increase in size in favor of the female. 
The variations of the module are interesting to observe. 
Their range is very much smaller than that of the indi- DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
vidual measures, which is a proof that the measures of the 
fossa largely compensate each other. Because of this 
quality of the module, it is of greater value than the 
individual measurements. 
There remain to be pointed out the relations of the size 
of the pituitary fossa to the circumference of the skull. 
We would meet with disappointment if we should expect 
to find a regular correspondence of those two values. 
Nevertheless there is a certain correspondence, for as we 
proceed to larger skulls, generally speaking, the fossa, 
also, will be found larger. This point cannot be better 
illustrated than by giving here the module circumference 
relations in detail. I will arrange these cases without 
relation to sex or color, neither of which seems to make 
any difference in this point, beginning at the lowest and 
advancing to the highest circumference. 
Circumf. Max. 
Module of 
Pituitary Fossa. 
Relation of 
Module to 
Circumf. 
48.0 cm. 
1.000 cm. 
20.8 cm. 
50.2 cm. 
0.967 cm. 
18.6 cm. 
50.8 cm. 
1.083 cm. 
21.3 cm. 
51.0 cm. 
0.917 cm. 
18.0 cm. 
51.2 cm. 
0.917 cm. 
17.8 cm. 
51.3 cm. 
0.950 cm. 
18.5 cm. 
51.5 cm. 
0.900 cm. 
17.4 cm. 
51.6 cm. 
1.033 cm. 
20.0 cm. 
51.7 cm. 
1.050 cm. 
20.3 cm. 
52.0 cm. 
0.983 cm. 
18.9 cm. 
52.0 cm. 
0.967 cm. 
18.6 cm. 
52.3 cm. 
1.167 cm. 
22.3 cm. 
52.7 cm. 
1.067 cm. 
20.2 cm. 
53.0 cm. 
x.133 cm. 
21.4 cm. 
53.0 cm. 
1.117 cm. 
21.1 cm. 
53.2 cm. 
1.117 cm. 
21.0 cm. 
54.2 cm. 
1.050 cm. 
19.4 cm. 
54.5 cm. 
1.083 cm. 
19.9 cm 
55.0 cm. 
1.017 cm. 
18.5 cm. 
56.0 cm. 
1.133 cm. 
20.2 cm. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
Divided into groups of five, these figures give the 
following^averages: 
Circumference. 
Average Module. 
Average Relation 
of Module 
to Circum. 
48.0-51.2 cm. incl. 
0.977 cm. 
19.3 cm. 
51.3-52.0 cm. incl. 
0.983 cm. 
19.0 cm. 
52.0-53.0 cm. incl. 
1.090 cm. 
20.7 cm. 
53.2-56.0 cm. incl. 
1.080 cm. 
19.8 cm. 
According to the above figures the average module, or 
the size of the pituitary fossa as represented by the 
modules, increases with the greater size of the skull, but 
apparently the increase ceases after the average size of 
the skull is passed. The maximum of the ratio of the 
module to the circumference corresponds to the maximum 
of the size of the fossa. 
It is not possible to establish from the foregoing data 
any law of correspondence of the proportion of the fossa 
to the circumference of the skull. This will be appre- 
ciated by the accompanying drawing. (Plate III, Fig. i). 
The paper might be finished here were it not for a 
peculiar difference of a little structure adjoining the 
pituitary fossa, in the white and in the negro. I refer to 
the space bounded by the anterior and posterior olivary 
ridges and including the optic groove and the olivary 
eminence. 
This space is, in general, very much narrower antero- 
posteriorly in the negro than in the white, and that in 
both sexes. The defect concerns especially the olivary 
eminence. 
Following are the antero-posterior measures of this 
space: 
White Male. 
White Female. 
Negro Male. 
Negro Female. 
Averages: 
0.562 cm. 
0.611 cm. 
0.425 cm. 
0.386 cm. 
Variations: 
0.20-0“ 5 cm 
0.30-0.85 cm. 
0.25-0.70 cm. 
0.10-0.70 cm. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
17 
The greater antero-posterior narrowness of the space in 
the negro is very evident. It can be expressed to a 
further advantage by the following curves. (Plate III, 
Fig. 2). 
The significance of marked difference in the antero- 
posterior extent of the space containing the optic tract and 
the olivary eminence, in the white and the negro, is 
obscure, but some light may be thrown on it by futher in- 
vestigations at autopsies. 
The medical value of these measurements lies in the 
fact, that they represent the dimensions which the pitu- 
itary fossa may acquire, in individual directions as well 
as a whole, in the normal state. Should in a given 
case, and particularly in a white person, any individual 
measure of the fossa, taken with care and according to 
the rules laid down in this paper, markedly exceed the 
variations of the same measure here recorded, such a 
measure may safely be considered abnormal. On the 
other hand, no pituitary fossa can safely be considered as 
abnormal in size so long as its individual measure, and its 
module, are not above the variations of the same measures 
here recorded. 
In an appendix will be found a reference list of the 
detail measures of the pituitary fossa on the four series 
of skulls examined. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
APPENDIX. 
The detail measurements of the four series of skulls: 
No. 
Diameter 
ant. post. 
Width. 
Depth. 
Diameter 
later, bet. pts. 
of ant. 
clinoids. 
Diameter 
a-post to ant. 
border of 
oliv. emin. 
Distance 
bet. the two 
oliv. ridges. 
Module. 
W+L+D 
3 
Circumf. 
of skull. 
Relation of 
module to circ. 
MX 1000 
C 
I 
1.25 cm. 
1.25 cm. 
0.85 cm. 
1.45 cm. 
1.65 cm. 
0.40 cm. 
1.117 cm. 
53.2 cm. 
21 .ocm. 
2 
1.25 
1.15 
0.95 
2-35 
I.60 
0.35 
1.117 
? 
? 
3 
1.00 
o.75 
0.95 
2.10 
I.60 
0.60 
0.900 
? 
? 
4 
I • IO 
1.30 
1.00 
2.60 
1.70 
0.60 
1.133 
? 
? 
5 
1.00 
1.30 
I.IO 
? 
? 
? 
1.133 
56.O 
20.2 
6 
0.75 
1.45 
0.75 
2.70 
1-45 
0.70 
0.983 
52.O 
18.9 
7 
0.85 
1.10 
I. IO 
2.70 
1.45 
0.60 
1.017 
55-0 
18.5 
8 
1.40 
1.10 
0.95 
2.50 
1.80 
0.70 
1.150 
? 
? 
9 
1.30 
1.30 
0.80 
2.80 
1.90 
0.60 
1.133 
53-0 
ab’t2i.4 
IO 
1.15 
1.50 
0.80 
2.90 
1.75 
0.60 
1.150 
? 
? 
ii 
1.20 
1.10 
1.00 
2.45 
1.70 
0.50 
1.100 
? 
? 
12 
1.05 
1.30 
0.85 
? 
1.90 
0.85 
1.067 
? 
? 
13 
1.20 
1.40 
0.60 
2.50 
1-95 
o.75 
1.06 
52.7 
20.2 
14 
1.05 
1.50 
0.95 
? 
1.60 
o.55 
1.167 
? 
? 
15 
0.90 
0.95 
0.90 
? 
1-45 
o.55 
0.917 
? 
? 
16 
0.90 
1.20 
1.00 
2.40 
1.60 
0.70 
1-033 
? 
? 
17 
1.45 
0.85 
0.90 
? 
2.00 
0.55 
1.067 
? 
? 
18 
1.00 
1.25 
1.00 
1.80 
1.60 
0.60 
1.083 
? 
? 
19 
1.30 
0.90 
0.95 
2.40 
2.00 
0.70 
1.050 
54-2 
19.4 
20 
1.25 
1.40 
0.70 
2.70 
1.80 
o.55 
1.117 
? 
? 
21 
1.00 
1.20 
1.00 
? 
1.70 
0.70 
1.067 
? 
? 
22 
1.15 
I .OO 
0.90 
? 
? 
? 
1.020 
? 
? 
23 
0.95 
I.OO 
0.80 
2.30 
1.30 
0.35 
0.917 
? 
? 
24 
1.20 
0.70 
0.70 
? 
? 
? 
0.867 
? 
? 
25 
1.10 
I.15 
1.20 
1.80 
1.50 
0.40 
1.150 
? 
? 
26 
1.40 
I .OO 
0.95 
? 
? 
? 
1.117 
? 
? 
27 
I. IO 
I.IO 
0.70 
? 
? 
? 
0-937 
? 
? 
28 
1.20 
I.IO 
O.9O 
2.00 
1.60 
0.40 
1.067 
? 
? 
29 
I. OO 
1.00 
0.80 
1.80 
1.20 
0.20 
0.933 
? 
? 
30 
1.25 
1.00 
1.15 
2.30 
1.80 
0.55 
1.133 
? 
? 
SKULLS OF WHITE MALE ADULTS.—Table I. DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
APPENDIX.—(Continued). 
No. 
Diameter 
ant. post. 
Width. 
Depth. 
Diameter 
later, bet. pts. 
of ant. 
clinoids. 
Diameter 
a-post. to ant. 
border of 
oliv. emin. 
Length 
of olivary 
eminence. 
Module. 
W+L4-D 
3 
Circumf. 
of skull. 
Relation of 
module to circ. 
MX 100 
C 
I 
o.go cm. 
1.00 cm. 
0.70 cm. 
2.00 cm. 
1.70 cm. 
0.80 cm. 
0.867 cm. 
? 
? 
2 
1.15 
1.50 
1.10 
2.60 
2.00 
0.85 
1.250 
? 
p 
3 
o.8o 
1.00 
0.90 
2.20 
1.45 
0.65 
0.900 
51.5 
17.4 
4 
o.8o 
1.10 
0.90 
? 
1.40 
0.60 
0.933 
? 
p 
5 
1.00 
1-35 
0.80 
2.45 
i-55 
0.55 
1.050 
51.7 
20.3 
6 
1.15 
1.10 
0.60 
1.75 
1.60 
0.45 
0.950 
51.3 
18.5 
7 
0-95 
M 
M 
O 
0.70 
? 
1.65 
0. 70 
0.917 
? 
? 
8 
0.90 
1.00 
1.20 
? 
1.50 
0.60 
1.033 
? 
p 
9 
1.30 
0-95 
0.85 
? 
1.90 
0.60 
1.033 
51.6 
20.0 
IO 
1.15 
0.85 
0.90 
2.40 
1.90 
0.75 
0.967 
50.2 
l8.6 
ii 
0.90 
0.90 
0.95 
? 
1.20 
0.30 
0.917 
? 
? 
12 
0.80 
0.80 
1.15 
? 
1.50 
0.70 
0.917 
51.0 
18.0 
13 
0.90 
1.25 
0.95 
? 
1-45 
0.55 
1-033 
? 
? 
14 
1.05 
O.go 
1.10 
? 
1.60 
0.55 
1.017 
? 
? 
15 
1.05 
1.00 
1.00 
? 
1.90 
0.85 
1.017 
? 
? 
16 
0.90 
1-25 
0.95 
2.30 
1.55 
0.65 
1-033 
? 
? 
17 
o.75 
1.00 
1.00 
? 
i-35 
0.55 
0.917 
? 
? 
18 
0.95 
0.90 
0.90 
2.15 
1.60 
0.65 
0.917 
? 
? 
19 
1.05 
1.20 
1.10 
2.40 
1-45 
0.40 
1.083 
49-0 
22.0 
20 
o.75 
1.20 
0.80 
2.60 
1.20 
0-54 
0.917 
51.2 
17.8 
21 
1.10 
1.30 
0.85 
2.70 
1.70 
0.60 
1.083 
50.8 
21.3 
22 
1.15 
1.10 
1.25 
? 
1.50 
0.35 
1.167 
? 
? 
23 
1.15 
1.10 
1.00 
? 
1.80 
0.65 
1.083 
? 
? 
24 
1.30 
1.10 
0.75 
2.35 
2.15 
0.85 
1.050 
50.5 
20.8 
25 
1.20 
0.85 
1.00 
? 
? 
? 
1.017 
51.0 
19.9 
26 
0.90 
1.15 
1.30 
2.15 
1.50 
O.60 
1.117 
? 
? 
27 
1.00 
1.20 
0.75 
? 
1.65 
0.65 
0.983 
ab’t 50.7 
ab’t 19.4 
SKULLS OF WHITE FEMALE ADULTS.—Table II. 20 
DIMENSIONS OF THE NORMAL PITUITARY FOSSA. 
APPENDIX.—(Continued). 
No. 
Diameter 
ant. post. 
Width. 
Depth. 
Diameter 
later, bet. pts. 
of ant. 
clinoids. 
Diameter 
a-post to ant. 
border of 
oliv. emin. 
Length 
of olivary- 
eminence. 
Module. 
W+L+D 
3 
Circumf. 
of skull. 
Relation of 
module to circ. 
(M X100) 
C 
I 
i. 2p cm. 
i. 20 cm. 
0.95 cm. 
2.00 cm. 
1.55 cm. 
0.35 cm. 
i. 117 cm. 
? 
? 
2 
I. oo 
1.00 
0.95 
2.40 
1.70 
O. 70 
0.983 
? 
? 
3 
1-25 
1.20 
0.90 
2.10 
1.50 
O.25 
x. 117 
53-0 
21.1 
4 
I .oo 
0.95 
0.95 
? 
I.65 
O.65 
0.967 
52.0 
18.6 
5 
? 
1.15 
1.10 
2.25 
1.15 
? 
? 
? 
? 
6 
1.15 
1.05 
0.70 
? 
I.40 
O.25 
0.967 
? 
? 
7 
1.20 
1.40 
1.00 
2.45 
I.60 
O.40 
1.200 
51.5 
23-3 
8 
0.85 
1.20 
1.00 
? 
1.25 
O.40 
1.017 
? 
? 
9 
I. IO 
1.30 
0.85 
3-io 
1.50 
O.40 
1.083 
54-5 
19.9 
No. 
Diameter 
ant. post. 
Width. 
Depth. 
Diameter 
later, bet. pts. 
of ant. 
clinoids. 
Diameter 
a-post. to ant. 
border of 
oliy. emin. 
Length 
of olivary 
eminence. 
Module. 
W+L+D 
3 
Circumf. 
of skull. 
Relation of 
module to circ. 
MX 100 
C 
I 
0.80 cm. 
1.00 cm. 
o.go cm. 
2.25 cm. 
i. 20 cm. 
0.40 cm. 
0.900 cm. 
? 
? 
2 
1.00 
1.00 
0.90 
2.20 
1.20 
0.20 
0.967 
? 
? 
3 
0.85 
1.30 
0.85 
2.20 
1.30 
0.45 
1.000 
48.0 
20.8 
4 
1.10 
1.55 
1.00 
2.60 
1.80 
0.70 
1.217 
49-5 
24.6 
5 
1.40 
1.30 
0.80 
2.30 
1-95 
0.55 
1.167 
52.3 
22.3 
6 
1.00 
1.00 
1.00 
2.25 
1.10 
0.10 
1.000 
? 
? 
7 
1.30 
1.30 
0.95 
? 
1.60 
0.30 
M 
M 
CO 
U3 
? 
? 
SKULLS OF NEGRO MALE ADULTS.—Table III. 
SKULLS OF NEGRO FEMALE ADULTS.—Table IV. Hrdlicka— Pituitary Fossa. 
PLATE I. 
Fig. 1. 
Fig. 2. 
Archives of Neurology and Psychopathology. Vol. I. 
THE HELIOTYPE PRINTING CO., BOSTON Hrdlicka—Variations of the Pituitary Fossa. 
PLATE II 
Fig. 1.— Curves showing the Percentage of 
Fossae within each length Variations of 
1 MM. 
Fig. 2.—Curves showing the Percentage of 
Fossae within each -width Variations of 
1 MM. 
Fig. 3.— Curves showing the Percentage ok 
Fossae within each depth Variations of 
I MM. 
Archives of Neurology and Psycho-Pathology. Vol. I. 
THE HELIOTYPF. PRINTING CO., BOSTON. Hrdlicka—Variations of the Pituitary Fossa 
PLATE III 
Fig. i..—Relations of the Module of the 
Pituitary Fossa to the Circumference 
of the Skull. 
Fig. 2.—Curves showing the Differences in 
the Antero-posterior Extent of the 
Space Inclosed within the Two Olivary 
Ridges, in front of the Pituitary Fossa, 
BETWEEN THE WHITES AND THE NEGROES 
of Both Sexes. 
Scale:- 
White Male 
White Female 
Colored Male 
Colored Female 
THE HELIOTYPE PRINTING CO., BOSTON. 
Archives of Neurology and Psycho-Pathology. Vol. I. STATE 
HOSPITALS 
PRESS. 
UTICA 
NEW YORK, 1899.