Darwinism Illustrated DARWINISM 
ILLUSTRATED 
WOOD-ENGRAVINGS 
EXPLANATORY OF THE 
THEORY OF EVOLUTION 
SELECTED BY AND DRAWN UNDER THE DIRECTION OF 
PROF. GEORGE J. ROMANES 
CHICAGO : 
The Open Court Publishing Company 
1892. COPYRIGHT, 1892, BY 
The Open Court Publishing Co. 
CHICAGO, ILL. PUBLISHERS’ PREFACE. 
This collection of wood-engravings, made under the 
direction of Professor George J. Romanes, illustrates 
his view of the theory of organic evolution. We here 
survey at a glance a number of instructive facts, so 
arranged that we can understand the truth of Darwin- 
ism as it were by intuition. 
Most of the illustrations are new and original : they 
have been drawn by artists under the personal super- 
vision of Professor Romanes. Others have been added 
from different sources, and Professor Romanes has 
taken pains to incorporate into this collection the most 
valuable and instructive drawings he could find. PREFACE. 
Several years ago Lord Rosebery founded, in the 
University of Edinburgh, a lectureship on “The Phi- 
losophy of Natural History,” and I was invited by the 
Senatus to deliver the lectures. I accepted the invi- 
tation, and subsequently constituted the material of 
my lectures the foundation of another course, which 
was given in the Royal Institution, under the title 
“ Before and after Darwin. ” Here the course extended 
over three years—namely from 1888 to 1890. The lec- 
tures for 1888 were devoted to the history of biology 
from the earliest recorded times till the publication of 
the “ Origin of Species ” in 1859 ; the lectures for 1889 
dealt with the theory of organic evolution up to the 
date of Mr. Darwin’s death, in 1882 ; while those of 
the third year discussed the further developments of 
this theory from that date till the close of the course 
in 1890. 
It is from these two courses—which resembled each 
other in comprising between thirty and forty lectures, 
but differed largely in other respects—that a special 
treatise has grown which is soon to be published under 
the title “Darwin and after Darwin.” The present 
engravings were collected for this special purpose and 
their detailed explanation will be found in the forth- 
coming book. My obligations to the Senatus of the University 
of Edinburgh, and to the Board of Management of 
the Royal Institution, have already been virtually 
expressed ; but I should like to take this opportunity 
of also expressing my obligations to the students who 
attended the lectures in the University of Edinburgh. 
For alike in respect of their large numbers, their keen 
intelligence, and their generous sympathy, the mem- 
bers of that voluntary class yielded a degree of stimu- 
lating encouragement, without which the labor of pre- 
paring the original lectures could not have been at- 
tended with the interest and the satisfaction that I 
found in it. 
My thanks are also due to Mr. R. E. Holding for 
the painstaking manner in which he has assisted me in 
executing most of the original drawings of the present 
collection. 
Lastly 1 must mention that I am indebted to Pro- 
fessors Le Conte, Cope, Heilprin, Marsh, Mr. and Mrs. 
Peckham, and the widow of the late Prof. Leidy, for 
kindly allowing me to use a number of their illustra- 
tions, not only in my English edition of “Darwin and 
After Darwin ” but also in American publications. 
Christ Church, Oxford, 
April igt/i, 1892. 
G. J. R. 
VI LIST OF ILLUSTRATIONS. 
PAGE 
Fig. i. Successive forms of Paludina, from the Tertiary de- 
posits of Slavonia i 
2. Skeleton of Seal 2 
3. Skeleton of Greenland Whale 3 
4. Paddle of Whale compared with Hand of Man 4 
5. Wing of Reptile, Mammal, and Bird 5 
6. Skeleton of Dinornis gravis 6 
7. Hermit-crabs compared with the cocoa-nut crab. ... 7 
8. Rudimentary or vestigial hind-limbs of Python .... 8 
9. Apteryx Australis 8 
10. Illustrations of the nictitating membrane in various 
animals named 9 
11. Rudimentary, or vestigial and useless, muscles of the 
human ear 10 
12. Portrait of a young male gorilla 11 
13. Lower extremities of a young child 12 
14. An infant, three weeks old, supporting its own weight 13 
15. Sacrum of Gorilla compared with that of Man, show- 
ing the rudimentary tail-bones of each 14 
16. Diagrammatic outline of the human embryo when 
about seven weeks old 15 
17. Front and back view of adult human sacrum 15 
18. Appendix vermiformis in Orang and in Man 16 
19. The same, showing variation in the Orang 16 
20. Human ear 17 
21. Foetus of an Orang 17 
22. Vestigial characters of human ears 18 
23. Hair-tractson the arms and hands of Man, as compared 
with those on the arms and hands of Chimpanzee. 19 
24. Molar teeth of lower jaw in Gorilla, Orang, and Man 20 PAGE 
Fig. 25. Perforation of the humerus (supra-condyloid fora- 
men) in three species of Quadrumana where it nor- 
mally occurs, and in Man, where it does not nor- 
mally occur 20 
26. Antlers of stag, showing successive addition of 
branches in successive years 21 
27. Fission of a Protozobn 22 
28. Hydra viridis, partly in section 22 
29. Successive stages in the division of the ovum, or 
egg-cell, of a worm 23 
30. Ovarian ovum a Mammal 23 
31. Amoeboid movements of young egg-cells 24 
32. Human ovum, mature and greatly magnified 25 
33. Stages in the formation of the polar bodies in the 
ovum of a star-fish 26 
34. Fertilization of the ovum of an echinoderm 26 
35. Fertilization of the ovum of a star-fish 27 
36. Karyokinesis of a typical tissue-cell (epithelium of 
Salamander) 27 
37. Study of successive changes taking place in the 
nucleus of an epithelium-cell, preparatory to di- 
vision of the cell 28 
38. Formation and conjugation of the pronuclei in 
Ascaris megalocephala 29-30 
39. Segmentation of ovum 31 
40. The contents of an ovum in an advanced stage of 
segmentation, drawn in perspective 31 
41. Formation of the gastrula of Amphioxus 32 
42. Gastrulation 33 
43. Gastrula of a Chalk Sponge 34 
44. Prophysema primordiale, an extant gastraea-form. . . 35 
45. Ideal primitive vertebrate) seen from the left side. . 36 
46. The same in transverse section through the ovaries. 36 
47. Amphioxus lanceolatus 37 
48. Balanoglossus . 38 
49. A large Sea-lamprey (Petromyzon marinus) 38 
50. Adult Shark (Carcharias melanopterus) 3g 
51. Diagram of heart and gill-arches of-a fish 40 
52. One gill-arch, with branchial fringe attached 40 
53. Diagram of heart and gill-arches in a lizard. 40 PAGE 
Fig. 54. Ideal diagram of primitive gill- or aortic-arches. . . 41 
55. The same, modified for a bird 41 
56. The same, modified for a mammal 41 
57. A series of embryos at three comparable and pro- 
gressive stages of development, representing each 
of the classes of vertebrated animals below the 
Mammalia 42 
58. Another series of embryos, also at three comparable 
and progressive stages of development, represent- 
ing four different divisions of the class Mammalia 43 
59. Diagram of geological succession of the classes of 
the Animal Kingdom 44 
60. Skull of Oreodon Culbertsoni 44 
61. 62. Horns of Cervus dicrocerus 44 
63. “ C. matheronis 44 
64. , “ C. pardinensis 44 
65. “ C. issiodorensis 44 
66. “ C. Sedgwickii 44 
67. Successive stages in the development of an existing 
Deer’s Antlers 43 
68. Homocercal tail 45 
69. Heterocercal tail 46 
70. Vertebrated but symmetrical fin (diphycercal) 46 
71. Tail of Archceopteryx 47 
72. Tail of modern Bird 47 
73. Archaeopteryx macura, restored 48 
74. Skeleton of Polar Bear. 49 
75. Skeleton of Lion 50 
76. Anterior limb of Man, Dog, Hog, Sheep, and Horse 51 
77. Posterior limb of Man, Monkey, Dog, Sheep, and 
Horse 32 
78. Posterior limb of Baptanodon discus, and anterior 
limb of Chelydra serpentina 33 
79. Paddle of a Whale 33 
80. Fossil skeleton of Phenacodus prim<evus 54 
81. Bones of the foot of four different forms of the peris- 
sodactyl type 55 
82. Bones of the foot of four different forms of the artio- 
dactyl type 56 
83. Feet and teeth in fossil pedigree of the Plorse 57 
IX PAGE 
Fig. 84. Palceotherium. (Lower Tertiary of Paris Basin). . . 58 
85. Hipparion. (New World Pliocene) 58 
86. Comparative series of Brains 59 
87. Ideal section through all the above stages 60 
88. Skulls of Canadian Stag, Cervalces Americanus, and 
Elk 61 
89. Transmutations of Planorbis 62 
90. Transformation of Strom/nis 63 
91. Pigeons. Drawn from life 64 
92. Pigeons (continued). Drawn from life 65 
93. Fowls. Drawn from life 66 
94. Fowls (continued). Drawn from life 67 
95. Pair of Japanese Fowls, long-tailed breed 68 
96. Canaries. Drawn from life 69 
97. Sebastopol, or Frizzled Goose 70 
98. The Dingo, or wild dog of Australia 70 
99. Dogs. Drawn from life 71 
100. Dogs (continued). Drawn from life 72 
101. The Hairless Dog of Japan , 73 
102. The skull of a Bull-dog compared with that of a 
Deer-hound 73 
103. Rabbits. Drawn from life 74 
104. Horses. Drawn from life 75 
105. Sheep. Drawn from life 76 
106. Cattle. Drawn from life 77 
107. Wild Boar contrasted with a modern Domesticated Pig 78 
xo8. Seasonal changes of color in Ptarmigan (Lagopns 
mutus) 79 
109. QLdicnemus crepitans,showing the instinctive atti- 
tude of concealment 80 
no. Imitative forms and colors in insects 81 
in. The larva of Puss Moth (Centra vinula) 82 
112. The larva of Puss Moth in disturbed attitude 82 
113. Three cases of mimicry 83 
114. Two further cases of mimicry; flies resembling a 
wasp in the one and a bee in the other 84 
115. A case of mimicry where a non-venomous species of 
snake resembles a venomous one 85 
117. Feather-footed pigeon 86 
118. Raia radiata 87 
X PAGE 
Fig. ng. Electric organ of the Skate 88 
120. Electric cells of Raid radiata 89 
121. The Garden Bower-bird (Amblyornis inornata) .... 90 
122. Courtship of Spiders 91 
123. Courtship of Spiders (continued) 92 
124. The Bell-bird {Chasmorhynchus niveus) 93 
125. C. tricarunculatus. ' 94 
xi DARWINISM 1L LUSTRATED. 
Fig. i.—Successive forms of Paludina, from the Tertiary deposits 
of Slavonia (after Neumayr). Fig. 2.—Skeleton of Seal, nat. size. Drawn from nature (R. Coll. Surg. Musi) 
2 Fig. 3—Skeleton of Greenland Whale, nat. size. The rudimentary bones of the pelvis are shown on a 
larger scale in the upper drawing. (From Prof. Flower.) 
3 Fig. 4 ■—Saddle of Whale compared with Hand of Man. Drawn 
from nature (A\ Coll. Surg. Mus ) • PTGRpD/lCTy L • 
B/1T- 
•BIR.D* 
7^'€.y-f • 
Fkj. 5.—Wing of Reptile, Mammal, and Bird. Drawn from nature 
{Brit. Mils) Fig. 6.—Skeleton of Dinorsis gravis, nat. size. Drawn from 
nature (Brit. Mas.) As separate cuts on a large; scale are shown, 
ist, the sternum, as this appears in mounted skeletons, and, 2nd, the 
same in profile, with its (hypothetical) scapulo coracoid attached. 
6 Fig. 7—Hermit-crabs compared with the cocoa-nut crab. On the left of the illustration one hermit-crab is represented as 
occupying a mollusk-shell, and another (larger specimen) as it appears when withdrawn from such a shell. On the right of 
the illustration the cocoa-nut crab is represented in its natural habitat on land. When full-grown, however, it is much larger 
than our hermit-crabs. The latter are drawn from life, natural size, the former from a specimen in the British Museum, 
i natural size. 
piRHUf lAJJl 0 
J’AGV'tU^ A . \lCfi T, 
S. ho/wy TEiwr/tTiori or 
JKflD - Lips. 
Fig. 8.—Rudimentary or vestigial hind limbs of Python, as exhib- 
ited in the skeleton and on the external surface of the animal. Drawn 
from nature, i nat. size (Zoological Gardens'). 
A<'o'/«E//77yry Hi/sp-umbs 
Img. g Apteryx Australis. Drawn from life in the Zoological 
Gardens g- nat size. The external wing is drawn to a scale in the 
upper part of the cut. The surroundings are supplied from the most 
recent descriptions. T^rtL'E; 
(jffL£L/& 
From Inside 
Owl 
From Inside 
Xofltfs 
Ot/jpj/j 
Sea Lion 
/7,°r 
Plica^ 
Semilunaris 
The Eyeball 
REMOVED 
A/7X 
Fig. io.—Illustrations of the nictitating membrane in the various animals 
named, drawn from nature. The letter N indicates the membrane in each 
case. In man it is called the plica semilunaris, and is represented in the 
two lower drawings under this name. In the case of the shark (Galeus) the 
muscular mechanism is shown as dissected. 
9 Fig. ii.—Rudimentary, or vestigial and useless, muscles of the 
human ear. (From Gray's Anatomy). Fig. 12. — Portrait of a young male gorilla (after Hartmann). Fig. 13.—Lower extremities of a young child. Drawn from life, 
when the mobile feet were for a short time at rest in a position of 
extreme inflection. I*IG- x4—An infant three weeks old, supporting- its own weight for 
over two minutes. The attitude of the lower limbs, feet, and toes, 
is strikingly simian. Reproduced from an instantaneous photograph, 
kindly given for the purpose by Dr. L. Robinson. 
13 Man 
Gorilla 
Fig. 15.—Sacrum of Gorilla compared with that of Man, showing 
the rudimentary tail bones of each. Drawn from nature (A\ Coll. 
Surg Mus.) Fig. 16 —Diagrammatic outline of the human embryo when about 
seven weeks old, showing the relations of the limbs and tail to the 
trunk (after Allen Thomson), r, the radial, and u, the ulnar, border 
of the hand and fore-arm; t, the tibial, and f, the fibular, border of 
the foot and lower leg; au, ear; s, spiral cord; v, umbilical cord; 
b, branchial gill slits; c, tail. 
.SvPR/rSh/lo’Js Lig. 
Fig 17.—Front and back view of adult human sacrum, showing 
abnormal persist-nce of vestigial tail-mu-cles. (The first drawing is 
copied from Prof. Watson’s paper in Journl. Anat. and Physiol., vol. 
79: the second is compiled from different specimens). 
15 Fig. 18.—Appendix vermiformis in Orang and in Man. Drawn 
from dried inflated specimens in the Cambridge Museum by Mr. 
J. J. Lister. II, ilium; Co, colon; C, ccecum; W, a window cut 
in the wall of the coecum; xxx, the appendix. 
Oranc 
Man 
Mam 
Fcetal 
Fig. 19 —The same, showing variation in the Orang. Drawn from 
a specimen in the Museum of the Royal College of Surgeons. 
16 Fig. 2D.—Human ear, modelled and drawn by Mr. Woolner. 
a, the projecting point. 
Fig. 21.—Foetus of an Orang. Exact copy of a photograph, 
showing the form of the ear at this early stage. Ci-l)fV^/f]\(z£E. 
ojkfl/JG-OifyrJcx. 
Fig. 22.- Vestigial characters of human ears. Drawn from nature. 
flUPl/thf fCET(/s 
.p/XRfthkY/PE. 
of the huymri- e/i/j 
H/ll)\Y'-Jll/1yAN' E/)\- 
18 IaV. 
/f>L £ CH'MPMZtl?. 
Fig. 23.— Hair-tracts on the arms and hands of Man, as compared 
with those on the arms and hands of Chimpanzee. Drawn from life. G’-ORJ ULA- 
N A T. S IZ E 
O KG- . 
Fig. 24.—Molar teeth of lower jaw in Gorilla, Orang, and Man 
Drawn from nature nat. size (A’. Mus. Coll. Surg ) 
SAKI. 
JAVAL0(\IS. 
l\hYj. 
Fig. 25.—Perforation of the humerus (supra-condyloid foramen) 
in three species of Quadrumana where it normally occurs, and in 
Man, where it does not normally occur. Drawn from nature (A’. Coll. 
Surg. Mus.) 
CAP'JCHl \). 
20 'fi'jsjtfe 
Ist Ye 
Fig. 26.—Antlers of Stag, showing successive addition of blanches 
in successive years. Drawn from nature {Brit. Mus.) 
21 Fig. 27.—Fission of a Protozobn. In the left-hand drawing the 
process is represented as having advanced sufficiently far to have 
caused a division and segregation both of the nucleus and the vesicle. 
In the right hand drawing the process is represented as complete. 
n, N, severed nucleus; vc, severed vesicle ; ps, pseudopodia; f , 
indigested food. 
Fig. 28.—Hydra viridis, partly in section. M, mouth; O, ovary, 
or bud containing female reproductive cells; T, testis, or bud con- 
taining male reproductive cells. In addition to these buds contain- 
ing germinal elements alone, there is another which illustrates the 
process of “gemmation”—i. e. the direct out-growth of a fully 
formed offspring. Fig. 29.—Successive stages in the division of the ovum, or egg cell, 
of a worm. (After Strasburger). a to d show the changes taking 
place in the nucleus and surrounding cell contents, which result in 
the first segmentation of the ovum at e: f and g show a repetition 
of these changes in each of the two resulting cells, leading to the 
second segmentation stage at h. 
Fig. 30—Ovarian ovum of a Mammal, (a) magnified and viewed 
under pressure, (6) burst by increased pressure, with yolk and 
nucleus escaping : (c) the nucleus more freed from yolk substance. 
(From Quain's Anatomy, after Allen Thomson). 
23 Fig. 3i•"“Amoeboid movements of young egg-cells, a, Amoeboid ovum of Hydra 
( ironi Balfour, after Klemenberg); 6, early ovum of Toxopucustes v&rieqcbtus* 
with pseudopodia-hke processes (from Balfour, after Selenka); c, ovum of 
lojcopneustes lividus, more nearly ripe (from Balfour, Hertwig). Ai to A4, 
the primitive egg-cell of a Chalk sponge (Leuculmis echinus), in four succes- 
sive conditions of motion. Bi to B8, ditto of a Hermit-Crab (Chondracanthus 
cornutus), in eight successive stages (after E. von Beneden). Ci to CX ditto 
of a Cat, in five successive stages (after Pfiuger'l. D, ditto of Trout; E, of a 
Hen; I\ of Man The first series is taken from the Encycl. Brit.-, the second 
from Ilackel s Evolution of Man. 
24 Fig. 32.—Human ovum, mature and greatly magnified. 
(After Hackel). 
25 fpn. 
Fig. 33. — Stages*in the formation of the polar bodies in the o\urn 
of a star fish (After Ifertwig). y v . germinal vesicle transformed 
into a spindle shaped system of fibres; pi, the first polar body 
becoming extruded \p.,p., both polar bod es fully extruded; f pn., 
female pronucleus, or residue of the germinal vesicle. 
Fig. 34.— Fertilization of the ovum of an echinoderm. (From 
Quain’s Anatomy, after Selenka). S, spermatozoon; mpr., male 
pronucleus; f p., female pronucleus. 1 to 4 correspond to D to G 
in the next figure. 
26 Fig. 35. — Fertilization of the ovum of a starfish. (From the 
Encycl. Brit, after Fol.) A, spermatozoa in the mucilaginous 
coat of the ovum; a prominence is rising from the surface of the 
ovum towards a spermatozoon; B, they have almost met; C, they 
have met; D, the spermatozoon enters the ovum through a distinct 
opening; H, the entire ovum, showing extruded polar bodies on 
its upper surface, and the moving together of the mile and female 
pronuclei; E, F, G, meeting and coalescence of the pronuclei. 
Fig. 36.—Karyokinesis of a typical tissue cell (epithelium of Sala- 
mander). (After Flemming and Klein). The series from A to I 
represents the successive stages in the movement of the chromatin 
fibres during division, excepting G which represents the “nucleus- 
spindle” of an egg-cell. A, resting nucleus; D, wreath-fo-m; E. 
single star, the loops of the wreath being broken; separation of 
the star into two groups of U-shaped fibres ; II, diaster or double 
star; I, completion of the cell-division and formation of two resting 
nuclei. In G the chromatin fibres are marked a, and correspond 
to the “equatorial plate”; b, achromatin fibres forming the nucleus 
spindle; c, granules of the cell-protoplasm forming a ‘polar star.” 
Such a polar star is seen at each end of the nucleus spindle, and is 
not to be confused wiih the diaster II, the two ends of which are 
composed of chromatin. 
27 Fig. 37.—Study of successive changes taking place in the nucleus of an epithel- 
ium-cell, preparatory to division of the cell. (From Quain's Anatomy, after 
Flemming), a, resting cell, showing the nuclear network; f>, first stage of 
division, the chromatoplasm transformed into a skein of closely contorted 
filaments; c to f, further stages in the growth and looping arrangement of 
the filaments; g, stellate phase, or aster; h, completion of the splitting of the 
filaments, already begun in f and g; i,j, k, successive stages in separation 
of the filaments into two groups; /, the final result of this (diaster); m to q, 
stages in the division of the whole cell into two, showing increasing contor- 
tion of the filaments, until they reach the resting stage at q. 
28 Fig. 38.—Formation and conjugation of the pronuclei in Ascaris megalo- 
cephala. (From Quain's Anatomy, after E. von Beneden). /, female 
pronucleus; m, male pronucleus; p, one of the polar bodies. 
I. The second polar body has just been extruded; both male and female pro- 
nuclei contain two chromatin particles; those of the male pronucleus are 
becoming transformed into a skein. 
II. The chromatin in both pronuclei now forms into a skein. 
Ha. The skeins are more distinct. Two attraction (or protoplasmic) spheres, 
each with a central particle united with a small spindle of achromatic 
fibres, have made their appearance in the general substance of the egg 
close to the mutually approaching pronuclei. The male pronucleus has 
the remains of the body of the spermatozoon adhering to it. 
III. Only the female pronucleus is shown in this figure. The skein is con- 
tracted and thickened. The attraction spheres are near one side of the 
ovum, and are connected with its periphery by a cone of fibres forming a 
polar circle, p.c.\ e.c., equatorial circle. 
Ilia. The pronuclei have come into contact, and the spindle-system is now 
arranged across their common axis. 
IV. Contraction of the skein, and formation of two U or V-shaped chromatin 
fibres in each pronucleus. 
V. The V-shaped chromatin filaments are now quite distinct: the male and 
female pronuclei are in close contact. 
29 VI., VII. The V-shaped filaments are splitting longitudinally; their structure 
of fine granules of chromatin is apparent in VII., which is more highly 
magnified. The conjugation of the pronuclei is apparently complete in 
VII. The attraction-spheres and achromatic spindle, although present, are 
not depicted in IV., V., VI., and VII. 
VIII. Equatorial arrangement of the four chromatin loops in the middle of 
the now segmenting ovum; the achromatic substance forming a spindle- 
shaped system of granules with fibres radiating from the poles of the 
spindle (attraction-spheres) ; the chromatin forms an equatorial plate. 
(Compare Fig. 36 G.) 
IX. Shows diagrammatically the commencing separation of the chromatin 
fibres of the conjugated nuclei, and the system of fibres radiating from the 
attraction spheres. (Compare again Fig. 36 G.) p.c., polar circle; e.c., 
equatorial circle; c.e., central particle. 
X. Further separation of the chromatin filaments. Each of the central 
particles of the attraction-spheres has divided into two. 
XI. The chromatin fibres are becoming developed into the skeins of the two 
daughter-nuclei. These are still united by fibres of achromatin. The 
general protoplasm of the ovum is becoming divided. 
XII. The two daughter-nuclei exhibit a chromatin network. Each of the 
attraction-spheres has divided into two, which are joined by fibres of 
achromatin, and connected with the periphery of the cell in the same way 
as in the original or parent sphere, III. 
30 Fig 39.—Segmentation of ovum. (After Hackel.) Successive 
stages are marked by the letters A, B, C. D represents several 
stages in advance of C. 
Fig. 40 —The contents of an ovum in an advanced stage of seg- 
mentation, drawn in perspective. (After Ilackel). 
31 Fig 41.— Formation of the gastrula of Amphioxus. (After Kowa- 
levsky). A, wall of the ovum, composed of a single layer of cells; 
B, a stage in the process of gastrulation; C, completion of the 
process: S, original or segmentation cavity of ovum; al, alimentary 
cavity of gastrula; ect, outer layer of cells; ent, inner layer of cells; 
b, orifice, constituting the mouth in permanent forms. Fig. 42 —Gastrulation A, Gastrula of a Zoophyte (Gastrophysemci). 
(After Hackel). B, Gastrula of a Worm (Sagitta). (After Kowa- 
levsky). C, Gastrula of an Echinoderm (Uraster). (After A. 
Agassiz). D, Gastrula of an Arthropod (Nauplius). (After 
Hackel). E, Gastrula of a Mollusk (Limncens). (After Eabl). 
F, Gastrula of a Vertebrate (Amphioxus). (After Kowalevsky). 
In all, d, indicates the intestinal cavity; o, the primitive mouth; 
s, the cleavage cavity; i, the endoderm, or intestinal layer; e, the 
ectoderm or skin-layer. Fig. 43.—Gastrula of a Chalk Sponge. (After Ifackel). A, External 
view. B, Longitudinal section, g, digestive cavities; o, mouth; 
i, endoderm; e, ectoderm. 
34 Fig. 44.—Prophysetna primordiale, an extant gastraea form. (After 
Hackel) (A). External view of the whole animal, attached by its 
foot to seaweed. (B.) Longitudinal section of the same. The 
digestive cavity (d) opens at its upper end in the mouth (m). 
Among the cells of the endoderm (g) lie amoeboid egg-cells of 
large size (e). The ectoderm {h) is encrusted with grains of sand, 
above the sponge spicules. 
35 Fig 45 —Ideal primitive vertebrate, seen from the left side. (After 
Ilackel). na. nose; au, eye; g, ear; md, mouth; ks, gill openings; 
x, notochord; mr, spinal tube; kg. gill-vessels; k, gill-intestine; 
hz, heart; ms, muscles; ma, stomach; v, intestinal vein; c, body- 
cavity; a, aorta; /, liver; d, small intestine; e, ovary; h, testes; 
n, kidney-canal; af, anus; Ih, true or leather-skin; oh, outer-skin; 
(epidermis); /, skin-fold, acting as a fin. 
Fig. 46.—The same in traverse section through the ovaries; lettering 
as in the preceding Fig. Fig. 47. Aviphioxus lanceolatus. (After Hackel). a, anus; au, eye; b, ventral muscles; c, body-cavity; 
ch, notochord; d, intestine; do and du, dorsal and ventral walls of intestine; f, fin-seam; h, skin; k, gills; 
ka, gill-artery; lb, liver; Iv, liver-vein; mi, brain-bladder; m 2, spinal marrow; mg, stomach; 0, mouth; 
p, ventral pore; r, dorsal muscle; s, tail-fin; t, aorta; v, intestinal vein; x, boundary between gill intestine 
and stomach-intestine; y, hypobranchial groove. Fig. 49.—A large Sea-lamprey (Petromyzon marinus), much reduced in size. (After Cuvier and Hackel). A series of 
seven gill-slits are visible. 
Fig. 48—Balanoglossus. (After A. Agassiz. r, proboscis; h, collar; k. gill-slits; d, digestive posterior intestine; 
v, intestinal vessel; a, anus. Fig 50.—Adult Shark {Carcharias melanopterus). (After Cuvier and Ilackel). Fig. 53.—Diagram of heart and gill-arches in a lizard. 
(After Owen ) The gill-arches, a a a \ and b b' b", 
are called aortic arches in air breathing vertebrata. 
Fig. 52.—One gill-arch, with 
branchial fringe attached. 
(After Owen.) H, Heart. 
Fig. 51.—Diagram of heart 
and gill-arches of a fish. 
(After Owen.) 
40 Fig. 56.— The same, modified for a 
mammal. (After Le Conte). 
Fig, 55.—The same, modified for a bird. 
(After LeConte). The dark lines show 
the aortic arches which persist. A, 
aorta; p, pulmonary arches; SC, S'C', 
sub-clavian; C, C', carotids. 
Fig. 54.,—Ideal diagram, of primitive 
gill or aortic arches. (After Rathke). 
H, outline of heart. The arrows 
show the course of the blood. 
41 _ lit 
_ hi , 
i 
nr 
t 
jii 
c>/r^K' 
Fk;. 57— A series of embryos at three comparable and progressive stages of 
development (marked I, II, III), representing each of the classes of verte- 
brated animals below the Mammalia. (After Hackel.) Ill 
Hog. 
Ill 
Calf. 
hi : 
Rabbit. 
Ill 
Man. 
Fig. 58.—Another series of embryos, also at three comparable and progressive 
stages of development (marked I, II, III), representing four different divis- 
ions of the class Mammalia. (After Hackel). 
43 P'ig. 59.—Diagram of Geological Succession of the Classes of the 
Animal Kingdom. (After Le Conte). 
Fig. 60.—Skull of Oreodon Culbertsoni. (After^Leidy). 
Fig. 61. 
Fig. 62. 
P ig. 63. 
Fig. 64. 
Fig. 65. 
Fig. 66. 
The series is reduced from Gaudry’s illustrations, after Farge, 
Croizet, Jobert and Boyd Dawkins. Fig. 67.—Successive stages in the development of an existing Deer’s 
Antlers. (After (Jaudry, but a better illustration has already been 
given on p. 100.) 
Fig. 68.—Homocercal Tail, showing (A) external form and 
(B) internal structure. Fig. 69.—Heterocercal Tail, showing (A) external form and 
(B) internal structure. 
Fig 70.—Vertebrated but symmetrical fin (diphycercal), showing 
(A) external form and (B) internal structure. Fig 72.—Tail of modern Bird 
The numerals indicate the fore- 
shortened, enlarged, and con- 
solidated joints ; /, terminal 
segment of the vertebral col- 
umn; D, shafts of feathers. 
Fig. 7i.—Tail of Archaopteryx. 
A indicates origin of simply- 
jointed tail. Fig. 73.—ArcJmopteryx macura, restored, $ nat. size. (After 
Flower). The section of the tail is copied from Owen, nat. size. Fig. 74. Skeleton of Polar Bear, drawn from nature (Brit. Mus.) 
49 Fig. 75.—Skeleton of Lion. (After Huxley). Fig. 76.—Anterior limb of Man, Dog, Hog, Sheep, and Horse. (After Le Conte). 
Sc, shoulder-blade; c, coracoid; a, b, bones of fore-arm; 5, bones of the wrist; 6, bones 
of the hand; 7, bones of the fingers. Fig. 77.—Posterior limb of Man, Monkey, Dog, Sheep, and Horse. (After Le Conte.) 1, Hip-joint; 
2, thigh bone; 3, knee-joint; 4, bones of leg; 5, ankle-joint; 6, bones of foot; 7, bones of toes. 
52 A 
B 
Fig. 78.—A, posterior limb of Babtanodon discus. (After Marsh). 
F, thigh-bone; I to VI, undifferentiated bones of the leg and foot. 
B, anterior limb of Chelvdra serpentina. (After Gegenbaur). U and 
R, bones of the fore-arm; I to V, fully differentiated bones of the 
hand, following those of the wrist. 
Fig. 79.—Paddle of a Whale. Fig. 8o.—Fossil skeleton of Phenacodus primcevus. (After Cope.) Fig. 8i.—Bones of the foot of four different forms of the perissodactyl type, showing gradual reduction in the number 
of digits, coupled with a greater consolidation of the bones above the digits. The series reads from right to left. 
Drawn from nature {Brit. Mus.) 
A, Elephant 
.B, Hyrax 
C, Rhinoceros 
D, Horse Fig. 82.—Bones of the foot of four different forms of the artiodactyl type, showing gradual reduction of the number of 
digits, coupled with a greater consolidation of the bones above the digits. The series reads from right to left. Drawn 
from nature (Brit. Mus.) 
A, HirpopoTAMUs 
B, Pig 
C, Deer 
D, Camel Equus: Qua- 
ternary and 
Recent. 
Piiohippus: 
Pliocene. 
Protohippus : 
Lower Plio- 
cene. 
Miohippus : 
Miocene. 
Mcsohippus: 
Lower Mio- 
cene. 
Orohippus : 
Eocene. 
Fig 83. — Feet and teeth in fossil pedigree of the Horse. (After 
Marsh), a, bones of the fore foot; b, bones of the hind foot; c, 
radius and ulna; d, tibia and fibula; e, roots of a tooth; /and g, 
crowns of upper and lower molar teeth. Fig. 84—Palccotherium. (Lower Tertiary of Paris Basin) 
Fig. 85.—Hipparion. (New World Pliocene). 
58 Fig. 86.—Comparative series of Brains. (After LeConte). The series reads from 
above downwards, and represents diagrammatically the brain of a Fish, a Reptile, 
a Bird, a Mammal, and a Man. In each case the letter A marks a side view, and 
the letter B a top view. The small italics throughout signify the following homo- 
logous parts: m, medulla; cb, cerebellum; op, optic lobes; cr, cerebrum and 
thalamus; ol, olfactory lobes. The series shows a progressive consolidation and 
enlargement of the brain in general, and of the cerebrum and cerebellum in 
particular, which likewise exhibit continually advancing structure in respect of 
convolution. In the case of Man, these two parts of the brain have grown to so 
great a size that they conceal all the other parts from the superficial points of view 
represented in the diagram. 
59 Fig. 87.—Ideal section through all the above stages. (After LeConte). Fig. 88.—Skulls of—A, Canadian Stag; B, Ccrvalces American ns; 
and C, Elk. (After Heilprin). Fig. 89.— Transmutations of Planorbis. (After Hyatt). Fig. 90.—Transformation of Strombus. (After Heilprin). 1, 1 a, Slrombus Leidy (1, typical), Pliocene; 
2, 2a, Stromlms accipitrinus (2a, typical) Recent. Fig. 91.—Pigeons. Drawn from life (prize specimens.) Fig. 92.—Pigeons, continued. Drawn from life (prize specimens). 
65 Fig. 93.—Fowls. Drawn from life (prize specimens). Fig. Q4-—Fowls, continued. Drawn from life (prize specimens). 
67 Fig. 9> -Pair of Japanese Fowls, long-tailed breed. Drawn from stuffed specimens 
in the British Museum. 
68 Fig. 96.—Canaries. Drawn from life (prize specimens). FlG. 97.—Sebastopol, or Frizzled Goose. Drawn lrom a photograph. 
Fig. 98.—'The Dingo, or wild dog of Australia, il0 nat. size. Drawn from life 
(.Zoological Gardens). Fig. 99.—Dogs. Drawn from life (prize specimens). 
71 Fig. ioo.—Dogs, continued. Drawn from life (.prize specimens). FlG 101.—The Hairless Dog of Japan, *„ r.at. size. Drawn from a photograph, 
kindly lent for the purpose by the proprietor. 
£ULLDOCr 
DEER F^OUND 
Fig. 102.—The skull of a Bull-dog compared with that of a Deerhound. Drawn 
from nature. 
73 Fig. 103.—-Rabbits. Drawn from life (prize specimens). SHIRE HORSE, 
"pRuJd£. William" 
5FT IO,rJ)~HGN 
Fig. 104. Horses. Drawn from life (prize specimens). 
75 Fig. 105.—Sheep. The illustrations are confined to British breeds. Drawn from 
life (prize specimens). 
76 y id)iL/\p/j) $doY. 
Jberpee^/gi/e. 
j^EREfORD. 
J^E'j. 
Lo /VC? )i o R/<f ED BREED. 
{ M / D L 4 A/ D S'.) 
Fig. 106.— Cattle. The illustrations are confined to British breeds. Drawn from 
life (prize specimens). 
77 Fig- 107.—Wild Boar contrasted with a modern Domesticated Pig. 
Drawn from life (.Zoological Gardens, and prize specimen). 
78 Fig. 108.— Seasonal changes of colour in Ptarmigan (.Lagopus 
mutus). Drawn from stuffed specimens in the British Museum, 
w nat. size, with appropriate surroundings supplied. 
79 Fig. iog.—(Edicnemus crepitans, showing the instinctive attitude of 
concealment. Drawn from a stuffed specimen in the British 
Museum, nat. size, with appropriate surroundings supplied. 
80 Fig. no.—Imitative forms and colours in insects. Drawn from nature (B. Coll. 
Surg. Mils.) 
81 Fig. iii.—The larva of Puss Moth (C. vimila) when undisturbed; 
full fed; natural size. 
Fig. i i2.—The larva of Puss Moth in its terrifying attitude after 
being disturbed; full-fed; natural size. 
82 1 Thojmi/I' fipRfl 
UPTflUS ■ TH&f/oL 
flcR/fy-gu^ir/f- 
'Dl/IDZ/4fJ-£UF{YTU$-\ 
fljAJlURbE • f/lfl^UE- 
VflPIDO ptEROPP. 
Fig. 113.—Three cases of mimicry. Drawn from nature: first two pairs nat. size, 
last pair % (K. Coll. Sure/. Mus.) 
83 ■DIPTERA- 
flVMENOPTERA- 
\VoLuceLL/\ /nans. 
Vespa Vulcaris. 
Vol . Bomb V'LArJs. 
Bombu's LapidariJs. 
Fig. 114. —Two further eases of mimicry; flies resembling a wasp in 
the one and a bee in the other. Drawn from nature: nat. size 
(A\ Coll. Surg. Alus.) Lf>, YrPP0L/\MPPjJP 
(Noa/ VesJoAioux) 
/"Jl\iJs 
( \sa/0 A? 0 Uf ) 
Pig. 115.—A case of mimicry where a non-venomous species of snake resembles a 
venomous one. Drawn from nature: % nat. size (R. Coll. Surg. Mus.). 
85 Fig. 117.—Feather footed pigeon. Drawn from nature. 
86 Fig. 118.—Rata radiata, representing the life size of the youngest 
individual in which muscle fibres have been found developing inio 
electric cells. 
87 Eig. 119—Electric organ of the Skate. The left-hand drawing (I) represents 
the entire organ (natural size) of a full-grown A’, radiata. This is a small 
skate, which rarely exceeds 5° centrns. in length; but in the large R. batis, the 
o rganmay exceed two feet in length. The other drawings represent single muscle- 
fibres in successive stages of transition. In the first of the series (II) the motor plate, 
and the nerves connected with it, have already been considerably enlarged. In the 
other three specimens, the fibre becomes more and more club-like, and eventually 
cup-like. These changes of shape are expressive of great changes of structure, as 
may be seen in the last of the series (V), where the shallow cup is seen in partial 
section. The electric plate lines the concavity of the cup, and is richly supplied with 
nerves (only a few of which are represented in the last drawing): the thick walls of 
the cup are composed of muscular fibres, the striation of which is distinctly visible. 
88 Fig. 120.—Eleclric cells of Raid radia/a. The drawing on the 
left represents one of the clubs magnified, as in the preceding wood- 
cut. The drawing on the right represents a number of these clubs, 
less highly magnified, in situ. Fig. i2i.—The Garden Bower-bird (Amblyornis inornata). Reduced 
from Gould's Birds of New Guinea to } nat. size. 
90 Fig. 122.—Courtship of Spiders. A few examples of some of the 
attitudes adopted by different species of males when approaching 
their females. (After Peckham). Fig. 123.—Courtship of Spiders. Continued from Fig. 122, similarly 
showing some of the attitudes of approach adopted by malrs of yet 
other different species. (After Peckham). 
92 Fig. 124. — The Bell-bird (Chasmorhynchus niveus, ir natural size). 
Drawn from nature {R. Coll. Surg. Mus.) In the drawing of the 
adult male the ornamental appendage is represented in its inflated 
condition, during courtship; in the drawing of the young male it is 
shown in its flaccid condition. 
93 Fig. 125.—C. tricarunculatus, i natural size. Copied from the Ibis. 
The ornamental appendages of the male are represented in a partly 
inflated condition.