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T. s. ii.

EDINBURGH LIBRARY

R27735L

0236

By order of the College, this B.oolc is not to he taken out
of the Library ( except after (3 p.m. until 10 a.m.) for one
month from this dale.

Physicians’ Hall,

CAMBRIDGE BIOLOGICAL SERIES.

General Editor : — Arthur E. Shipley, M.A., F.R.S.

FELLOW AND TUTOR OF CHRIST’S COLLEGE, CAMBRIDGE.

MORPHOLOGY

AND

ANTHROPOLOGY

Edition: C. J. CLAY AND SONS,
CAMBRIDGE UNIVERSITY PRESS WAREHOUSE,
AVE MARIA LANE.

AND

H. K. LEWIS,

13C, GOWER STREET, W.C.

©lasfloto: 50, WELLINGTON STREET.
TLctpjifl : F. A. EROCKHAU8.

Ditto IQorlt : THE MACMILLAN COMPANY.
Bombag anb Calcutta: MACMILLAN AND CO., Ltd.

MORPHOLOGY

AND

ANTHROPOLOGY

A HANDBOOK FOR STUDENTS

W. L. H. DUCKWORTH, M.A.,

FELLOW OF JESUS COLLEGE, CAMBRIDGE ;

UNIVERSITY LECTURER IN PHYSICAL ANTHROPOLOGY;
CORRESPONDANT ETRANGER DE LA SOCIETE D’ANTHROPOLOGIE DE PARIS

Cambridge :

at the University Press

I9°4

Cambridge :

PRINTED BY J. & C. E. CLAY,
AT THE UNIVERSITY PRESS.

TO HENRY DUCKWORTH, ESQ., J.P.,
F.L.S., F.G.S., F.R.G.S.

PKEFACE.

AS the Introductory Chapter of this Volume deals with its
il aim and scope, any further exposition of these would be
superfluous here. I hope that the materials thus brought together
may prove useful to Students, particularly to those who combine
Physical Anthropology with Human Anatomy in preparation
for the Cambridge Natural Sciences Tripos. Inasmuch as such
students are already familiar with anatomical terms, a general
acquaintance with the significance of these has been assumed.

I believe the method indicated, however inadequately, herein,
to be the most profitable for anthropological work on the physical
side : and I am convinced that upon some such basis only, can
Physical Anthropology justify its claim to an independent place
among the biological sciences.

The subject is now perfectly well-defined, and possesses so
extensive a literature, that even a cursory review like the present
volume has assumed proportions for which I must offer an apology.
Several departments of the subject (and particularly Anthro-
pometry) have merely been sketched in outline. A certain
amount of repetition will be noticed, but is justifiable in view
of the greater completeness conferred upon successive sections
of the book. Most of the illustrations have been prepared by
myself, in many instances from the original specimens or pre-
parations.

Like other reviews, this cannot be other than a process of
stocktaking. I have attempted to submit the main points in
evidence up to date; yet however desirable an absolutely fixed
standpoint may appear, it should not be forgotten that opinion
must be adjustable to the requirements of every new fact, pro-
vided the latter be correctly observed and accurately recorded.

vin

PREFACE

It is a pleasant duty to express my gratitude to those who
have aided me ; to my father, and to Professor Alexander Macalister,
for ever-ready help and encouragement ; to Professor Elliott Smith
and to Dr Marett Tims, who kindly read parts of certain Chapters
(viz. xv and vi), upon the subject-matter of which they are
recognised as authorities of the highest competence.

Mr F. S. Scales, of Jesus College, Cambridge, gave me most
valuable help in preparing the illustrations for reproduction.
My warm thanks are also due to the Editor of the Biological
Series, and to the authorities and staff of the University Press at
Cambridge.

The following have kindly lent blocks for illustrations, or
have given permission to copy figures in other publications : Dr
Nelson Annandale, late of Edinburgh, now Assistant Curator at
the Calcutta Museum; M. J. Deniker and Messrs W. Scott
and Co.; Professor E. Dubois; Professor Elliott Smith; Sir H. H.
Johnston, G.C.M.G., K.C.B. ; Professor Kollmann and Messrs
Fischer, of Jena; Messrs Macmillan and Co.; Mr Parsons; Pro-
fessor Schwalbe and the Redaktion of the Bonner Jahrbiicher;
the late Professor Selenka and the Konigliche Akademie cler
Wissenschaften zu Mimchen ; Professor Strahl and Messrs Kreidl,
of Wiesbaden.

The following have allowed the use of tables or information
already published elsewhere :

Dr Ballantyne and Professor Cunningham of Edinburgh ;
Professor Eisler of Halle and Professor Le Double of Tours ;
Professor Parker and Haswell and Messrs Macmillan and Co.

I have endeavoured to render full acknowledgement, and hope
that no omission has been made. References to literature are
provided in the text : a special index contains the names of
authors quoted. Where possible, I have attempted to verify or
check statements by personal observation.

Advie,

Strathspey.

Oct. 21, 1904.

CONTENTS.

Dedication ....

Preface

Index of Illustrations
Addenda and Corrigenda .

List of Abbreviations .
Chapter I. Introductory

PAGE

vii

xxvi

xxviii

1—12

Section A. Comparative Anatomy and Morphology
of Eutherian Mammals

13—154

Chapter II.

III.

IV.

VI.

The Mammalia: and the application of
the Methods of Morphology to their
Classification 13 — 27

The Members of the Mammalian Order
Primates 28 — 50

On the General Anatomy of the Primates 51 — 101

The Crania of the Simiidae (Primates) . 102—121

The Dental System of the Primates . 122 — 154

Section B. Embryology 155—216

Chapter VII. The Evidence of Human Embryology . 155 — 191

VIII. The same continued .... 192 — 216

CONTENTS

Section C.

Variation in Anatomical Conformation

Chapter

IX.

Anatomical Variations .

Comparative Craniology and Craniometry
(with an Appendix on Cranial Defor-
mations)

XI.

The Cranial Indices, Angles, and Capacity

XII.

Comparative Osteology . . . .

XIII.

The same continued . . . .

XIV.

The Comparative Morphology of the Soft
Tissues

XV.

The Comparative Morphology of the Cen-
tral Nervous System . . . .

XVI.

The Morphological Varieties of the Ho-
miuidae

Section D. Palaeontology
Chapter XVII. Fossil Primates

Chapter XVIII. Conclusion

Indexes. General Index

Names of Authors quoted .

PAGE

217—495

217—225

226—256

257—278

279—306

307—345

346—390

391—451

452—495

496—542

543—546

547—560

561—564

INDEX OF ILLUSTRATIONS.

PAGE

Fig. 1. Drawing of a dissection of the genito-urinary system of a Chimpanzee.

From Tyson’s “ Orang-outang, sive Homo Sylvestris. Or, the
Anatomy of a Pygmie.” London, 1699 ..... 2

Fig. 2. Drawings of the head and skull of a young Orang-utan, and of a
negro, to shew the method of determining the facial angle of
Camper (cf. Chapter xi.). From Camper’s original memoir . 3

Fig. 3. Blumenbach’s “norma verticalis” of three crania; A, an “Ethiopian” ;

B, Georgian woman ; C, a Tunguse ...... 4

Fig. 4. The longitudinally-bisected skull of a male Gorilla .... 6

Fig. 5. The longitudinally-bisected skull of an aboriginal native of Australia 7

Fig. 6. Left cerebral hemisphere of an aboriginal native of Australia . . 8

Fig. 7. The stereograph of Broca 9

Fig. 8. Occipital view of the cranium of a Bird (Larus) ..... 17

Fig. 9. Occipital view of the cranium of a Dog 17

Fig. 10. Shoulder girdle of a Beptile (Iguana) ; to shew the elements of the

girdle in a comparatively undifferentiated condition ... 17

Fig. 11. Shoulder girdle of a Prototherian Mammal (Echidna) ... 18

Fig. 12. Shoulder girdle of an Eutherian Mammal (Man) ; to shew the reduc-
tion in number of elements remaining distinct .... 18

Fig. 13. Shoulder girdle of a Prototherian Mammal (Echidna) ... 21

Fig. 14. Cranium of Sarcophilus, a Metatherian or Marsupial Mammal . 22

Fig. 15. Cranium of an Eutherian Mammal (Dog) 23

Fig. 16. Scheme of Primate Descent 30

Fig. 17. General external appearance of a Lemur 34

Fig. 18. Cranium, with mandible, of Lemur varius ..... 34

Fig. 19. Part of the alimentary canal of a Lemur : note the curiously con-
torted colon, and the enormous appendix eaeci .... 35

Fig. 20. Six views of the right cerebral hemisphere of a Lemur . . 36-37

Fig. 21. Cranium, with mandible, of Cebus capucinus (Cebidae) ... 38

Fig. 22. Part of the alimentary canal of a Cercopithecus monkey (Cercopitlie-

cidae) : note the lack of contortion in the colon, and the absence

of an appendix caeci 38

1' ig. 23. The left cerebral hemisphere of an American (Platyrrhine) ape,

Ateles variegatus : the lateral and mesial aspects of the hemi-
sphere are shewn 39

Fig. 24. The left cerebral hemisphere of a Nasalis monkey (Cercopithecidae):
the lateral and mesial aspects are shewn. (Hose Donation n. Mus.

Anat. Cant.) 49

Xll

INDEX OF ILLUSTRATIONS

Fig. 25.

Fig. 26.
Fig. 27.

Fig. 28.
Fig. 29.

Figs. 30
Fig. 32.
Fig. 33.
Fig. 34.

Fig. 35.
Fig. 36.

Fig. 37.
Fig. 38.
Fig. 39.
Fig. 40.

Fig. 41.

Fig. 42.
Fig. 43.

Fig. 44.

Fig. 45.

Fig. 46.

Fig. 47.

The cerebral hemispheres of a Gibbon (Simiidae) : the lateral and
mesial aspects are shewn. (Hose Donation n. Mus. Anat. Cant.)
Cranium, with mandible, of Hapale jaechus (Hapalidae) .

An adnlt male Nasalis or Proboscis Monkey; a variety of Semno-
pithecus (Cercopitbecidae) from Borneo. (Specimen, Hose Dona-
tion, No. n. Mus. Anat. Cant.)

Cranium, with mandible, of a Macacus monkey (Cercopitbecidae) .
Adult male Gorilla (Simiidae) ; the hair has been lost owing to
inadequate preservation in alcohol. (Holt Donation, Mus. Anat.

Cant.)

and 31. Other views of the same specimen

Cranium, with mandible, of a young Gorilla (Simiidae) .

Cranium, with mandible, of an adult Gorilla (Simiidae) .

Lateral aspect of the right cerebral hemisphere of a young Gorilla
(Simiidae). The olfactory nerves are attenuated in point of size:
the cerebral surface is much more convoluted than in the preced-
ing examples and recalls the appearance of the human cerebrum.

Cf. Figs. 20, 23, 24, 25, and p. 38

This is Fig. 18 repeated

Cutaneous musculature of the head of Lemur mongoz to shew
some of the more definite constituents of the muscular sheet .

l'AGE

46
46

This is Fig. 20 repeated

This is Fig. 19 repeated

This is Fig. 28 repeated

Lumbar portion of the vertebral column of a Cercopithecus monkey
(Cercopitbecidae), to shew the anapophyses projecting laterally

from the vertebral pedicles .

Mesial section of the (frozen) body of a Cynocephalus monkey
(Cercopitbecidae). Note the enormous size of the jaws, and the
comparatively small thoracic capacity and extent ; the vertebral
column is much less sinuous than in Man, but the anterior lumbar

convexity is incipient and distinct

Scapulae, (a) of a Cercopithecus Monkey, (6) of Man

55-56

Deep dissection of the plantar muscles of a Cercopithecus monkey
(Cercopitbecidae) to shew the origins of the M. fiexor accessorius
digitorum (M. quadratus plantae), and of the M. flexor longus
hallucis. (From a dissection by Mr R. Crawford) ... 64

Deep flexor tendons of the manus of a Cercopithecus monkey (Cer-
copithecidae) to shew the origins of the flexor longus pollicis,
and of the lumbrical muscles. (From a dissection by Mr Graham-
Smith) 64

Dissection of the nuchal and cervical muscles of a young Baboon
(Cynocephalus ; Cercopitbecidae). The occipito-scapular muscle,
a simian characteristic, is shewn 65

The left cerebral hemisphere of a Cercopithecus monkey (Cercopithe-
cidae). The main features are similar to those of the human
brain : on the mesial aspect the small post-splenial gyrus A. Retzii
is not visible, and the fascia dentata has not been exposed . . 67

Viscera of a Nasalis monkey (Cercopithecidae) : the extraordinarily
modified form of the stomach and the consequent displacement of
the liver to the right are to be noticed. These features are found
throughout the genus Semnopithecus, which includes many species
of monkeys found in Asia 69

INDEX OF ILLUSTRATIONS Xlll

PAGE

Fig. 48. Lateral aspect of the right lung of a Cercopithecus monkey (Cerco-

pithecidae) to shew the lobus azygos impar 70

Fig. 49. Lateral aspect of the left lung of a Cercopithecus monkey (Cerco-
pithecidae). The heart is also shewn. The lung is divided into
three lobes, thus differing from the human lung of the left side,

while resembling the right human lung 70

Fig. 50. This is Fig. 32 repeated 73

Fig. 51. This is Fig. 33 repeated 73

Fig. 52. Crania of Gorilla and Simia ; the former is distinguished by the

brow-ridges which are continuous from one orbit to the other . 76

Fig. 53. Nasal bones of Simiidae; (A) Gorilla, (B) Chimpanzee, (C) Orang-
utan ........... .77

Fig. 54. Nasal bones and intermaxillary (premaxillary) bone of a young

Gorilla ............ 77

Fig. 55. Diagram of the nasal bones and premaxilla in the preceding figure . 77

Fig. 56. The lumbar vertebrae of an Orang-utan, shewing one vestigial apo-

physial process (in the first vertebra of the lumbar series). The
slight anterior concavity of this part of the vertebral column is to
be noted. Cf. also Fig. 40 for anapophyses ..... 80

Fig. 57. Diagrams of the articulations between two lumbar vertebrae, (A) of
Gorilla, (B) of Man, to shew the more incomplete interlocking in

the latter example 80

Fig. 58. Posterior aspect of the knee-joint of a young Gorilla (right limb),

shewing the annular form of external articular cartilage . . 82

Fig. 59. Facial musculature of an adult Gorilla. Note the great development
of the anterior fibres of the platysma. The specimen forms part
of the Holt donation to the Cambridge Collection ... 85

Fig. 60. A dissection of the pectoral and axillary regions in an adult Gorilla:
the references are as follows :

1. M. pectoralis abdominalis (chondro-epitrochlearis). 2. M.
pectoralis major (cut). 3. M. pectoralis minor. 4. Laryngeal
sac extending into the axilla. 5. Tendon of M. latissimus dorsi,
with the M. latissimo-condyleus extending down the arm . . 86

Fig. 61. Dissection of the outer side of the thigh of an adult female Chim-
panzee, shewing the two heads of the M. biceps : also the great
sciatic nerve and its division ....... 86

Fig. 62. This is Fig. 34 repeated 88

Fig. 63. Mesial (A) and frontal (B) aspects of the right cerebral hemisphere
of a Gorilla (from a specimen in the Anatomy School at Munich).

Note the very great similarity in appearance, as regards the mesial
aspect, to the human cerebral hemisphere. The rhinal fissure
(incisura temporalis) is conspicuous. In (B) note the uncovered
state of the insula and the lack of definite anterior limbs of the
fissure of Sylvius 91

Figs. 64, 65, 66. Dissection of the lower limb of a Chimpanzee to shew the
distribution of the cutaneous nerves. Note the lack of cutaneous
fibres from the obturator nerve, and the absence of filaments from
the anterior tibial nerve to the cleft between the hallux and first

t°e 94-95

Fig. 67. Diagram (to scale) of the relations of the stomach and large intes-
tine in an adult male Gorilla (“ Cy ”) 96

Fig. 68. Abdominal and pelvic viscera of an adult male Gorilla, seen from
the right side. Note the extent to which the caecum and appendix
have descended into the pelvic cavity 97

D. M.

XIV

INDEX OF ILLUSTRATIONS

Fig. 69.
Fig. 70.

Pig. 71.
Fig. 72.
Fig. 73.

Fig. 74.

Fig. 75.

Fig. 76.
Fig. 77.

Fig. 78.

Fig. 79.
Fig. 80.
Fig. 81.
Fig. 82.

Fig. 83.
Fig. 84.
Fig. 85.
Fig. 86.
Fig. 87.
Fig. 88.
Fig. 89.

Lower surface of the liver of a Gorilla. (Mus. Anat. Cant.)

Cranium (with mandible) of Hylobates miilleri : note the absence of
an auditory bulla; there are spheno-parietal and lacrymo-ethmoidal
articulations. Note also the number of the teeth

Cranium (with mandible) of an Orang-utan (Simiidae) .

Cranium with mandible of a Chimpanzee (Simiidae)

Crania, with mandibles, of (A), young Gorilla, and (B) young Chim-
panzee (Simiidae)

Cranium of an Orang-utan (Simiidae) bisected in the median
sagittal plane

Cranium of an aboriginal native of Australia (Hominidae) bisected
in the median sagittal plane. N.Pr. represents the anterior or
ethmoidal portion of the cranial base ; Pr.B. is the middle or
basi-occipito-sphenoidal portion ; B.Op. represents the plane of
the foramen magnum

Cranium of a Baboon (Cercopithecidae) bisected in the median
sagittal plane ..........

Cranium of a Dog (Carnivora, Canidae) bisected in the median
sagittal plane; to shew the two sections into which the cranio-
facial axis has been conveniently divided .....

This and the three succeeding figures represent the component parts
of the cranial axis in the several stages which mark the path of
evolution of the human type (Fig. 81) from the generalised mam-
malian type (Fig. 78, with which cf. Fig. 77). In the latter (Fig.
78) the line B.Pr. represents the comparatively stable middle
portion, extending from the basion (cf. Chapter x.) to the pro-
sphenion, or most anterior point of the sphenoid bone. B.Op.
represents the plane of the foramen magnum ; and Pr.N., the line
from the prosphenion to the nasion, represents conventionally the
plane of the cribriform fossa. These indications apply to the
whole series of figures (78—81 inclusive)

Basis crauii of an Orang-utan, shewing the position of the foramen
magnum, far back in contrast with its position in the human
skull. Fig. 75 should also be compared with Fig. 77, when the
contrast will be observed

Right upper canine and post-canine teeth of a Lemur. (No. 4, Mus.

Zool. Cant.)

Left lower canine and post-canine teeth of a Lemur. (No. 4, Mus.
Zool. Cant.)

Right upper canine and post-canine teeth of Cebus capucinus. (No.

1093, Mus. Zool. Cant.)

Left lower canine and post-canine teeth of Cebus capucinus. (No.

1093, Mus. Zool. Cant.)

Right upper canine and post-canine teeth of a Macacus monkey
(Cercopithecidae)

Left lower canine and post-canine teeth of a Macacus monkey

(Cercopithecidae)

Right upper canine and post-canine teeth of Hylobates miilleri.
(W.L.H.D. priv. coll.)

PAGE

103

105

107

108
112

115

116

117

118
118

120

123

INDEX OF ILLUSTRATIONS

Fig. 90. Left lower canine and post-canine teeth of Hylobates mulleri.

(W.L.H.D. priv. coll.)

Fig. 91. Enlarged view of the lower premolar tooth of a Lemur .

Fig. 92. Right upper canine and post-canine teeth of an Orang-utan. (ad. <f

W.L.H.D. priv. coll.)

Fig. 93. Left lower canine and post-canine teeth of an Orang-utan. (ad. A

W.L.H.D. priv. coll.)

Fig. 94. Right upper canine and post-canine teeth of a Gorilla, (ad. A

W.L.H.D. priv. coll.)

Fig. 95. Left lower canine and post-canine teeth of a Gorilla, (ad. A

W.L.H.D. priv. coll.)

Fig. 96. Right upper canine and post-canine teeth of a Chimpanzee, (ad. A

W.L.H.D. priv. coll.)

Fig. 97. Left lower canine and post-canine teeth of a Chimpanzee, (ad. A

W.L.H.D. priv. coll.)

Fig. 98. Right upper canine and post-canine teeth of an aboriginal native of

Australia. (Mus. Anat. Cant.)

Fig. 99. Left lower canine and post-canine teeth of an aboriginal native of
Australia. (Mus. Anat. Cant.) .......

Fig. 100. Incisor teeth of a Lemur. (No. 4, Mus. Zool. Cant.)

Fig. 101. Incisor teeth of Cebus capucinus. (No. 1093, Mus. Zool. Cant.) .

Fig. 102. Incisor teeth of a Macacus monkey

Fig. 103. Incisor teeth of Hylobates mulleri. (ad. A W.L.H.D. priv. coll.)
Fig. 104. Incisor teeth of an Orang-utan. (ad. S W.L.H.D. priv. coll.)
Fig. 105. Incisor teeth of a Gorilla, (ad. A W.L.H.D. priv. coll.)

Fig. 106. Incisor teeth of a Chimpanzee. (young $ W.L.H.D. priv.

doll.)

Fig. 107. Incisor teeth of an aboriginal native of Australia. (Mus. Anat.

Cant.)

Fig. 108. An accessory dental mass (x) in the maxilla of a native of New
Britain. (Mus. Anat. Cant. W.L.H.D. del.) .

Fig. 109. Two accessory dental masses (x, x) in the maxilla of a native of
New Britain. (Mus. Anat. Cant. W.L.H.D. del.)

Fig. 110. Accessory cusps in the molar teeth of an Egyptian. (Mus. Anat.

Cant. W.L.H.D. del.)

Fig. 111. Left upper teeth of a young Gorilla : with accessory dental masses

(Specimen, priv. coll. W.L.H.D.)

Fig. 112. Gemination of the last molar tooth in the mandible of an Orang-
utan. (Selenka coll., Munich)

Fig. 113. Mandible of an Orang-utan (ad. A ) with an accessory molar tooth
on the right side. (Hose Donation II. Mus. Anat. Cant.) .

Fig. 114. Accessory teeth in the maxilla of an Orang-utan. (Selenka coll.

Munich)

Fig. 115. Mandible of an aboriginal Australian, with a supernumerary

incisor tooth. (Mus. Anat. Cant.)

Figs. 116, 117. Diagrams of the' primitive molar cusps, shewing the change
in position which gives rise to the tritubercular type of molar tooth
Fig. 118. Diagram of the cusps in an upper molar tooth : the indications are
AE, antero-external, AI, antero-internal, PE, postero-external,
PI, postero-internal cusp : “ x ” represents the position in which
additional cusps usually appear, as seen in Fig. 120, which
represents an upper molar tooth

PAGE

123

124

128

131

133

134

135
135
137
137

137

138

139

140
147

149

xvi

Fig. 119.

Fig. 120.
Fig. 121.
Fig. 122.

Fig. 123.

Fig. 124.

Fig. 125.

Fig. 120.

Fig. 127.

Fig. 128.

Fig. 129.

Fig. 130.
Fig. 131.
Fig. 132.

Fig. 133.

Fig. 134.

Fig. 135.

Fig. 136.

Fig. 137.

Fig. 138.

Fig. 139.

INDEX OF ILLUSTRATIONS

Diagram of the cusps in a lower molar tooth: additional cusps tend
to appear at “ y ” as shewn in Fig. 121, which also represents a
lower molar tooth with an accessory cusp. For the significance
of the letters, cf. Fig. 118

Diagram of the cusps in an upper molar tooth ....
Diagram of the cusps in a lower molar tooth .....

A and B, outline drawings of a human foetus (said to be 4| months
old), from photographs, and of the actual size of the specimen
C and D, similar drawings (of actual size) of a foetal gorilla.
(Mus. Zool. Cant.)

A and B, outline drawings from photographs of palmar and plantar
surfaces of the extremities of a human foetus (No. 29 of the Lee
Collection), said to be 4 months old
C and D, corresponding palmar (C) and plantar (D) surfaces of
the extremities of a foetal gorilla. (Mus. Zool. Cant.)

Diagrammatic representation of the topographical relations of
important organs to the vertebrae in the foetus at two different
epochs

Section through the upper thoracic region in a human infant (at
birth) : the scapulae are placed laterally, and have not acquired
the position which they occupy in the adult

Section through the abdomen of a human infant (at birth) ; the
lower surface of the section is shewn. There is no duodenal

mesentery . . . ,

Mesial section (A) of a human foetus at about the end of the 5th
month of pregnancy ; (B) the corresponding section of an adult

cynocephalous monkey

Lateral (A) and ventral (B) aspects of the right cerebral hemisphere
of a foetus of five months ........

Mesial aspect of the right cerebral hemisphere of a foetus of slightly
greater age than the preceding example . . . . .

The skull of a foetus at the ninth month, viewed in norma verticalis
The skull of a foetus at the ninth month, viewed in norma lateralis

The os innominatum (A and B) and sacrum (C and D) of a foetus
at the ninth month

The lateral surface of the right cerebral hemisphere of a new-born

infant

The liver of a human foetus at the ninth month ; the inferior

surface is shewn

Caecum, with vermiform appendix, of a human foetus at the ninth

month

Cranium of a human foetus at about the fifth month, viewed in
norma verticalis .....•••••
Cranium and mandible of a human foetus at about the fifth month,
viewed in norma lateralis ....••••
Mesial section of a human foetus at about the fifth month of

pregnancy

Two views of the right cerebral hemisphere of a human foetus of
about 5 months : A, shewing the exposed insula, and the paucity
of sulci ; B, to shew the close connection of the olfactory nerve
with the lower part of the insula

PAGE

149

159

100

163

164

165

167

168

169

172

175

177

179

180
181
181
182

184

INDEX OF ILLUSTRATIONS

XVII

Fig. 140.
Fig. 141.

Fig. 142.
Fig. 143.

Fig. 144.
Fig. 145.
Fig. 146.

Fig. 147.

Right lateral aspect of the abdomen of a human foetus of about
5 months ; the caecum with its appendix is exposed ; the final
position of both will be lower, and some circumduction of the
latter may occur in later stages

Livers of two human foetuses at about the 5th montb. In neither
is the caudate lobe so distinct as in the Cercopithecidae, nor is the
quadrate lobe yet detached from the (parent) right lobe. (A is a
spirit specimen, B has been preserved in Muller’s fluid and shews
the true form of the organ)

Diagram of the appearance in section of an early human ovum
(from Kollmann, after Graf v. Spee). The amnion is complete .

Diagram (modified from Selenka) of the section through an early
ovum of a Semnopithecus monkey, and the adjacent uterine
tissues. A general similarity to the arrangement which obtains
in the human ovum is here seen. A. Decidual cells of uterine
mucous membrane. B. Deeper decidual cells. G. Maternal
capillary vessels opening into the intervillous spaces. D.
Remnant of the wall of a maternal capillary vessel. E. Foetal
ectoderm (chorionic). E'. Foetal ectoderm (non-chorionic). M.
Foetal mesoderm. H. Foetal entoderm. S. Syncytium.
As in Fig. 142, the amnion is complete .....

Diagram representing the process of inversion of the germinal
layers

Diagrammatic section of an early human embryo (modified from
Mali’s figure published by Kollmann)

Diagram of the human embryo and its coverings, to shew the
proportionate sizes of the allantois and the yolk-sac. (Cf.
Kollmann, Entw. des Menschen, Fig. 35, p. 79, and Fig. 104,
P- 175)

Diagram of a rabbit embryo and its coverings, for comparison with
Fig. 146 ; to shew the proportionate sizes of the allantois and the
yolk-sac. Adapted from van Beneden’s figure as modified by
Marshall

Fig. 148.

Fig. 149.

Fig. 150.
Fig. 151.

Fig. 152.

Fig. 153.

Fig. 154.

Diagram of an early embryo of Semnopithecus (Cercopithecidae)
(after Selenka), to shew that the “intervillous” space is primarily
an intercellular space of the uterine epithelium. A. Decidual
cells of uterine mucous membrane. B. Deeper decidual cells.

C. Maternal capillary vessels opening into the intervillous spaces.

D. Remnant of the wall of a maternal capillary vessel. E.

Foetal ectoderm (chorionic). E'. Foetal ectoderm (non-
chorionic). M. Foetal mesoderm. H. Foetal entoderm.
S. Syncytium

Foetus of Hylobates miilleri, about 57 mm. in length ; the discoid
placenta is shewn. (Specimen, Hose donation, hi. Mus. Anat.
Cant.)

Foetus of an Orang-utan, with discoid placenta. (After Strahl) .

(A) Human embryo; (B) Embryo of Hylobates rafflesii. (After
Selenka)

(A) Human embryo; (B) Embryo of Semnopithecus cephalo-
pterus. (After Selenka)

(A) Human embryo ; (B) Embryo of Macacus cynomolgus. (After
Selenka) .

(A) Human embryo ; (B) Embryo of Semnopithecus nitratus.
(After Selenka)

PAGE

186

187

195

196

197

198

199

200

201

208

213

214

xvm

INDEX OF ILLUSTRATIONS

Fig. 155.
Fig. 156.
Fig. 157.

Fig. 158.

Fig. 159.

Fig. ICO.

Fig. 161.
Fig. 102.

Fig. 163.
Fig. 104.

Fig. 105.

Fig. 160.

Fig. 107.
Fig. 168.

Fig. 109.

Fig. 170.

Fig. 171.
Fig. 172.

Fig. 173.

Fig. 174.

Fig. 175.
Fig. 176.
Fig. 177.
Fig. 178.
Fig. 179.
Fig. 180.

(A) Human embryo ; (B) Embryo of Macacus cynomolgus.

(After Selenka)

(A) Human embryo ; (B) Embryo of Macacus cynomolgus.

(After Selenka) ..........

A. Human embryo. B. Embryo of Hylobates miilleri at
an age corresponding to that of the human embryo represented
in A. C. Another aspect of the embryo Hylobates represented
in B. (A. Original drawing) .......

Imperfect post-orbital wall : the spheno-maxillary fissure being
abnormally wide : cranium of Australian aboriginal. (Mus. Anat.
Cant. W.L.H.D. photo.)

Fronto-squamous articulation in the temporal region, and fronto-
maxillary articulation on the inner orbital wall of the skull of an
aboriginal native of Australia. Cf. Figs. 21 and 32. (Mus. Anat.
Cnnt. W.L.H.D. photo.)

Dilated laryngeal sacculus (from a specimen in the Anatomy

School at Athens)

Simian type of the appendix caeci in a human infant
(A) Human sternum (of an Australian aboriginal) resembling the
sternum of a Gorilla (B), inasmuch as the pre-meso-sternal
articulation is opposite the third, instead of the second costal
cartilage. (Mus. Anat. Cant. W.L.H.D. photo.)

The human skull viewed in (1) norma verticalis, (2) norma lateralis,
(3) norma facialis, (4) norma basilaris, and (5) norma occipitalis.
Diagram of a skull with indications of the principal named points;
the lines refer to certain measurements “in projection” to which

further reference is made in the text

Human skull placed in position, with the “base-line” of the
Frankfort agreement in the horizontal plane .

Flower’s Craniometer in the position for measuring the maximum

cranial length

A second variety of Craniometer .

Pearson’s head-spanner in the position for measuring the auricular

cranial height

Horizontal cranial circumference: according to Flower and to

Turner respectively

Principal named cranial points indicated on a diagram of the
human skull ..........

Broca’s stereograph

Mesial section of the skull of an aboriginal Australian, shewing the
divisions of the cranial base .... ...

The same specimen as that shewn in Fig. 172 ; to indicate

Daubenton’s angle

The same specimen as that shewn in Fig. 172 ; to indicate the

occipital and basilar angles of Broca

Scaphocephalus

Klinocephalus and annular constriction .

Trigonocephalus

Plagiocephalus

Thyrsoceplialus

Geographical distribution of the practice of artificial deformation
of the skull

PAGE

214

215

216
223

223

224

225
228

229

231

238

239

240

242

245

247

248

253

254

255

INDEX OF ILLUSTRATIONS

XIX

Fig. 181.
Fig. 182.
Fig. 188.
Fig. 184.

Fig. 185.
Fig. 186.

Fig. 187.
Fig. 188.

Fig. 189.

Fig. 190.
Fig. 191.
Figs. 192-

Fig. 196.
Fig. 197.
Fig. 198.

Fig. 199.

Fig. 200.
Fig. 201.
Fig. 202.

PAGE

Tracing of the skull of a young Chimpanzee bisected in the median
sagittal plane. (Mus. Zool. Cant.) ...... 269

Tracing of the skull of an aboriginal native of Australia, bisected
in the median sagittal plane. (Mus. Anat. Cant.) . . . 270

Tracing of the skull of an European, bisected in the median
sagittal plane. (Mus. Anat. Cant.) ...... 270

A. represents the centrum of a lumbar vertebra: the “anterior
vertical diameter” exceeds the “posterior vertical diameter.”

B. is added to indicate the manner in which the sum of the
anterior vertical diameters may be compared with that of the
posterior vertical diameters ....... 282

Kurto-rachic type of lumbar conformation in the vertebral column :
there is an anterior lumbar convexity. This conformation is
typical of the (adult) Hominidae ...... 285

Koilo-rachic type of lumbar conformation in the vertebral column :
there is an anterior lumbar concavity. This conformation is
common in the Simiidae and Primates other than the Hominidae.

In the foetal human being and some adult Hominidae this type
is however found to obtain ........ 285

Diagram representing the dimensions compared in the “ index of
the lumbar curve” ......... 286

AB joins the thoracic and sacral prominences : Cl) is the per-
pendicular, the length x of the whole column, being also measured
and taken as = 100 the index of ensellure ..... 288

Pelvis of an Orang-utan (Hose donation ii. Mus. Auat. Cant.); to
shew the flattened iliac bones, the straight narrow sacrum, and
transversely contracted pelvic brim 289

The pelves of (A) Hylobates, (B) Gorilla, and (C) Man . . . 293

Left os innominatum (A) of Gorilla, (B) of Man .... 294

-195. The female pelvis. (Fig. 192.) The normal form.

(Fig. 193.) The pelvis in Rickets, with the brim widened
laterally and compressed antero-posteriorly. (Fig. 194.) The
kyphotic pelvis, in which the transverse diameter is narrowed,
and the antero-posterior diameter increased. (Fig. 195.) The
pelvis with bilateral synostosis of the sacro-iliac synchondroses . 303

Right scapula of a Rabbit ........ 304

Right human scapula 304

Diagram of a scapula, shewing the lines by which the seapulo-
spinal angle is included 305

Diagrams of the bones of the arm and forearm in (A) Man, and
( B ) Woman : to shew the greater obliquity of the forearm in the
latter sex 310

Femora; (A) of H. neanderthalensis (Spy, No. 1): (B) of H.
sapiens ' 312

Femur of Pithecanthropus erectus, (A) the anterior, (B) the
external aspect 312

Femur of an Orang-utan (Hose donation ii.) : this specimen is
drawn to a larger scale than the bones represented in Figs. 200
and 201 ...

312

Fig. 203.

Fig. 204.
Fig. 205.
Fig. 206.

Fig. 207.
Fig. 20H.

Fig. 200.

Fig. 210.
Fig. 211.

Fig. 212.
Fig. 213.
Fig. 214.

Fig. 215.
Fig. 210.

Fig. 217.
Fig. 218.

Fig. 219.

Fig. 220.
Fig. 221.

Fig. 222.

INDEX OF ILLUSTEATIONS

PAGE

Upper end of a human femur: Platymeria may be due to
(1) extension outward of a flange-like process (cf. the flange-
like process in humeri of Gorilla and Megaladapis) ‘x’ as in
Eutheria: (2) extension inwards as at ‘ y ’ in certain human
femora: (3) ‘x’ and ‘y’ may coexist in certain human femora . 315

Lateral (external) aspect of the upper end of the platymeric femur
of an Orang-utan

Lateral (internal) aspect of the specimen represented in Fig. 204.

(Hose donation n. Mus. Anat. Cant.) 316

Two views, (A) the anterior aspect, and (B) the posterior aspect of
the upper end of a very platymeric human femur: the flange-like
projection x' obscures the lesser trochanter when the femur is
seen from in front (A) ........ 317

Diagram of a section through a very platymeric human femur . 318

Diagrams of the areas of muscular attachments to the anterior
surface of the femur in (A) Man, (B) a Cercopithecus monkey . 319

Astragali (of the left side) of (A) Man, (B) Chimpanzee, shewing
the greater obliquity of the neck in the latter animal . . . 326

Osteometric board used in the Cambridge Anatomy School . . 328

Diagrams to represent the skeleton of the limbs as compared in
the inter-membral index: if the lower limb be considered as of
constant length, the upper limb may be relatively either short as

in (A), or long, as in (B) 329

Diagram of the bones as compared in the radio-humeral index:
the length of the humerus being taken as the constant factor, the
radius may be relatively either short (A) or long (B) . . . 333

Diagram of the bones as compared in the tibio-femoral index : the
length of the femur being taken as the constant factor, the length
of the tibia may be relatively either short ( A ), or long (B) . . 336

Diagrams of the bones as compared in the femoro-liumeral (or
humero-femoral) index: the length of the femur being taken as
the constant factor, the length of the humerus may be relatively

either short (A), or long (B) 338

Diagrams shewing relative proportions of average Caucasian,
Negro, Eskimo, and Pangan (male and female) .... 345
Bush-woman of South Africa. The characteristic features of the
hair of the head, and the accumulation of gluteal fat (steatopygia)

are evident in this individual 357

Two sections of scalp hairs of a (negrito) Semang from the Malay
Peninsula. (Skeat Exped. ; Mus. Anat. Cant.) .... 359
Diagrams of the appearance of the eye. (A) normal, (B) epican-
thus, the epicanthic fold (P) giving rise to the appearance known

as that of the Mongolian eye 363

Diagram of a molar tooth of the right upper series. AE, antero-
external cusp. AI, antero-internal cusp. PE, postero-external
cusp. PI, postero-internal cusp, x, region in which small

accessory cusps appear 371

Laryngeal saccules in Man (cf. Fig. 160 and context) . . . 375

Larynx of a Kroo negro, dissected from the right side ; there is an
accessory muscle, viz. an accessory M. thyro-arytenoideus . *. 375

Diagrams illustrative of the three commonest modes (in order
of frequency) of the origin of the great arterial trunks from the
aorta in Europeans 375

INDEX OF ILLUSTRATIONS

XXI

Fig. 223. Anomalous origin of the right subclavian artery (R.s.) in a negro .

Fig. 224. Palmar arteries (superficial and deep arches) in the left hand of a
Kroo negro dissected at Cambridge. (W.L.H.D.)

Fig. 225. Cutaneous musculature of a Raccoon, to shew the several con-
stituents; (a) M. platysma, ( b ) M. sphincter colli, (c) M. dorso-
humeralis, (d) M. abdomino-humeralis. (After Parsons)

Fig. 226. Dissection of the facial musculature of an aboriginal native of
S. Australia. (Mus. Anat. Cant.) ......

Fig. 227 (after Kollmann). The human encephalon at about the twentieth
day. The telencephalon is that portion of the primitive neural
tube which is represented anteriorly to the interrupted line .

Fig. 228 (after His). The human encephalon at a stage corresponding to
that represented in Fig. 227 .......

Fig. 229. Scheme of the mammalian cerebrum with the several components
indicated. Left lateral aspect. (Elliott Smith) ....

Fig. 230. Scheme of the mammalian cerebrum, with the several components
indicated. Mesial aspect. (Elliott Smith) ....

Fig. 231. The central portion of Fig. 230 on a larger scale. (Elliott Smith)

Fig. 232. Scheme of the mammalian cerebrum with the several components
indicated. Ventral aspect. (Elliott Smith) ....

Fig. 233. Schematic section in a horizontal plane through the mammalian
cerebrum. (Elliott Smith)

Fig. 234. Coronal section through the cerebral hemisphere of a Reptile
(Hatteria). Differences of shading demarcate the marginal
pallium from the pyriform lobe and the corpus striatum. The
neopallium is developed between the two former portions of the
cerebrum, and is indicated very vaguely (for its extent is not
actually known) by a dark band at the junction of the marginal
pallium and pyriform lobe ........

Fig. 235. Coronal section through the cerebral hemisphere of a lowly
Mammal (Ornithorhynchus : Prototheria) shewing the limits of
the marginal pallium and the neopallium (cf. Fig. 236). The
corpus striatum does not appear in this section, and the pyriform
lobe is merged in the lower part of the margifial pallium. The
mesial aspect (as in Fig. 234) is to the left

Fig. 236. Mesial aspect of the right cerebral hemisphere of a lowly Mammal
(Ornithorhynchus: Prototheria). The rhinencephalon and mar-
ginal pallium are shaded to distinguish them from the neopallium

Fig. 237. Lateral (A), and basal (B) views of the right cerebral hemisphere
of a human foetus of five months. In (A) the transverse occipital
sulcus is an artefact

Fig. 238. Lateral aspect of a cerebral hemisphere upon which are indicated
the most constant of the neopallial furrows found in the Eutheria.
The pseudo-sylvian and supra-sylvian sulci are to be particularly
noticed. (This and the following illustration are kindly lent by
Dr Elliott Smith)

Fig. 239. Mesial aspect of a cerebral hemisphere upon which are indicated
the most constant of the neopallial furrows found in the Eutheria

Fig. 240. The mesial aspect of the left cerebral hemisphere of Cheiromys
madagascariensis

Fig. 241. Diagram (after Elliott Smith) to represent the most constant and
archaic sulci on the surface of the cerebral hemisphere of the
higher Mammalia ..........

PAGE

376

381

384

393

394

395

396
396

399

400
405

408

411

412

XXU

INDEX OF ILLUSTRATIONS

Fig. 242.
Fig. 243.
Fig. 244.
Fig. 245.
Fig. 246.
Fig. 247.

Fig. 248.

Fig. 249.

Fig. 250.

Fig. 251.

Fig. 252.

Fig. 253.

Fig. 254.

Fig. 255.

Fig. 256.

Fig. 257.
Fig. 258.

Fig. 259.

Fig. 260.

Fig. 261.

Fig. 262.

Fig. 263.

PAGE

Mesial aspect of the right hemisphere of the brain in a human
foetus at the sixth month ........ 419

Right cerebral hemisphere of an aboriginal of Australia. (Mus. Anat.

Gant. W.L.H.D. photo.) 424

Left cerebral hemisphere of an aboriginal of Australia. (Mus. Anat.

Cant. W.L.H.D. photo.) 424

Left cerebral hemisphere of an aboriginal of Australia. (Mus. Anat.

Cant. W.L.H.D. photo.) 425

Right cerebral hemisphere of an aboriginal of Australia. (Mus. Anat.

Cant. W.L.H.D. photo.) 425

Right cerebral hemisphere of an aboriginal Australian. The
occipital convolutions are shewn. (Mus. Anat. Cant. No. 2.

W.L.H.D. del.) 426

Left cerebral hemisphere of an aboriginal Australian. The

occipital convolutions are shewn. (Mus. Anat. Cant. No. 2.

W.L.H.D. del.) 427

Right cerebral hemisphere of an aboriginal Australian. The
occipital convolutions are shewn. (Mus. Anat. Cant. No. 3.

W.L.H.D. del.) .428

Left cerebral hemisphere of an aboriginal Australian. The

occipital convolutions are shewn. (Mus. Anat. Cant. No. 3.

W.L.H.D. del.) 429

Right cerebral hemisphere of an aboriginal Australian. The
occipital convolutions are shewn. (Mus. Anat. Cant. No. 4.
W.L.H.D. del.) 429

Left cerebral hemisphere of an aboriginal Australian. The

occipital convolutions are shewn. (Mus. Anat. Cant. No. 4.
W.L.H.D. del.)

Right cerebral hemisphere of an aboriginal Australian. The
occipital convolutions are shewn. (Mus. Anat. Cant. No. 1.
W.L.H.D. del.)

Left cerebral hemisphere of an aboriginal Australian. The

occipital convolutions are shewn. (Mus. Anat. Cant. No. 1.
W.L.H.D.' del.)

Part of the left hemisphere of the cerebrum of a negro (No. 2) in
the Cambridge Anatomical Collection

Part of the mesial surface of the right cerebral hemisphere of a
negro (No. 1). (W.L.H.D. del.)

Part of the mesial aspect of a negro brain (No. 2). (W.L.H.D. del.)

The sulcus lunatus is shewn in each cerebral hemisphere of a
young Zulu (Mus. Roy. Coll. Surg.)

Right cerebral hemisphere of a Bengali. The occipital convolutions
are shewn. (Mus. Anat. Cant. W.L.H.D. del.) ....

Left cerebral hemisphere of a Bengali. The occipital convolutions
are shewn. (Mus. Anat. Cant. W.L.H.D. del.) ....

Left cerebral hemisphere of a Tamil. The occipital convolutions
are shewn. (Mus. Anat. Cant. W.L.H.D. del.) ....

Right cerebral hemisphere of a Chinaman from Singapore. The
occipital convolutions are shewn. (Mus. Anat. Cant. W.L.H.D.
del.)

The sulcus lunatus is shewn in each cerebral hemisphere of a Bush
native. (Mus. Roy. Coll. Surg.)

430

431

432

433

434

435

437

438

439
442

INDEX OF ILLUSTRATIONS

XX1U

Fig. 264.
Fig. 265.

Fig. 266.

Fig. 267.

Fig. 268.
Fig. 269.

Fig. 270.

Fig. 271.

Fig. 272.
Fig. 273.

Fig. 274.
Fig. 275.
Figs. 276-

Figs. 284

Figs. 292-

Fig. 300.
Fig. 301.
Fig. 302.
Fig. 303.

Fig. 304.

Fig. 305.

PAGE

The suleus lunatus is shewn in each cerebral hemisphere of a Bush
native. (Mus. Roy. Coll. Surg.) . . . • • • 442

Right cerebral hemisphere of a human foetus ; the olfactory nerves
are not present, and in the proportions of the hemispheres the
cerebrum resembles that of Cetacea. (Mus. Anat. Cant. ) . . 444

Mesial aspect of the left cerebral hemisphere of the same brain as
that represented in Fig. 265 ........ 444

The conjoined cerebral hemispheres of a Cyclopian human monster
at the eighth month of foetal life ....... 445

Lateral view of the left aspect of the brain represented in Fig. 267 445
Mesial aspect of a human cerebral hemisphere in which the corpus

callosum was not developed (after Forel) 446

The right cerebral hemisphere of a microcephalic idiot girl (Bertha
Roemer). The specimen is in the Anatomical Museum at Halle 448
The right cerebral hemisphere of an anthropoid ape (a Gorilla) for
comparison with the cerebral hemisphere of the microcephalic
human being. (Mus. Anat. Cant. W. L. H. D. del.) . . . 448

The microcephalic human brain represented in Fig. 270, here
viewed from above ......... 449

Brain of a Gorilla (Mus. Anat. Cant. “H”), as seen from above:
for comparison with the microcephalic human brain shewn in
Fig. 272 449

Diagram to represent the relations of several human racial types as
indicated by their cranial features. Figures in the vertical column
represent values of the cephalic index, those in the horizontal line
being values of the prosthionic (or alveolar) index . . . 457

Diagram to represent the relations of several human racial types,
as indicated by their cranial features. The figures in the vertical
column represent values of the cranial capacity, those in the
horizontal line being values of the cephalic index . . . 459

-283 incl. Representative cranial types I — YII (corresponding to
the seven groups described in the text) seen in norma verticalis :
the figures are reduced so that the maximum cranial length is
uniform throughout the series. (Mus. Anat. Cant. W.L.H.D.
del.) 463—465

—291 incl. Representative cranial types I — VII seen in norma
lateralis; the figures are reduced so that the basi-nasal length
is uniform throughout the series. The extraordinary range of
variety in this dimension is expressed by the difference in size of
the drawings when the latter are thus proportionately reduced.

(Mus. Anat. Cant. W.L.H.D. del.) . . . . . 465 — 467

-299 incl. Representative cranial types I — VII seen in norma
facialis (Mus. Anat. Cant. W.L.H.D. del.) .... 468 — 469

Bush-man of South Africa. (Photo, lent by Messrs W. Scott & Co.) 481
Bush-woman of South Africa. (Photo, lent by Messrs W. Scott & Co.) 481
Map to represent the distribution (x) of pygmy races of Man . . 484

Two Bambute pygmies from Central Africa (from a photograph
kindly lent by Sir H. H. Johnston) 485

A young Semang negrito from the Malay Peninsula. (From a
photograph kindly lent by Dr N. Annandale.) .... 488

Cranium, with mandible, of Megaladapis insignis, a gigantic extinct
Lemur. The upper incisor teeth are vestigial .... 498

XXIV

INDEX OF ILLUSTRATIONS

Fig. 306.

Fig. 307.

Fig. 308.
Fig. 309.
Fig. 310.

Fig. 311.

Fig. 312.

Fig. 313.

Fig. 314.
Fig. 315.

Fig. 316.

Fig. 317.

Fig. 318.

Fig. 319.

Fig. 320.
Fig. 321.

Scheme of cusps of the upper molar teeth of Megaladapis. The
two anterior cusps are connected by a transverse ridge, leaving the
postero-external cusp isolated

Scheme of cusps of the lower premolar teeth of Megaladapis. The
antero-external and postero-internal cusps are connected by a
ridge. The third or intermediate internal cusp is minute in size

Canine and upper premolar teeth (upper jaw, right side) of an
extinct gigantic Lemur, Megaladapis insignis ....

Teeth of upper (to the left) and lower series of an extinct gigantic
Lemur, Megaladapis madagascariensis

Crania of ( A ) Adapis parisiensis, a fossil Lemur ; and (B) Lemur
varius, a typical modern Lemur. The crania are closely similar
in form. (Mus. Zool. Cant. W.L.H.D. del.) ....

Scheme of the cusps in an upper molar tooth of Hyopsodus. The
posterior lingual cusp is the smallest and is inconspicuous in the
last upper molar tooth

Scheme of the lower molar cusps in Hyopsodus. The oblique ridge
connects the antero-internal (lingual) and postero-external (labial)
cusp

Teeth (A, the upper B, the lower series) of Nesopithecus, an
extinct primate mammal intermediate between Lemurs and Apes.
The lower incisor teeth are spatulate, the molar teeth (except
in the last) bear four cusps, and the last molar tooth has but
three cusps. The teeth are ape-like rather than lemuroid. The
upper molar teeth were probably tritubercular. (From a specimen
in the Natural Histoi-y Museum, South Kensington)

Scheme of an upper molar tooth of Oreopitbecus : the cusps are
four in number, and there is a sagittally-direeted groove

Mandible of Oreopithecus bamboli (an extinct monkey from Italy,
resembling the Cercopithecidae) : the molar teeth have a distinct
“ talon ” bearing one or, in the last tooth, two cusps .

Cranium, with mandible, of Mesopithecus pentelici, an extinct
European (Greek) monkey. The general characters resemble those
of the Cercopithecidae. (Cf. Fig. 28)

Teeth of Mesopithecus pentelici ; A, lower left series (the premolars
and molars are shewn). B, the upper right series; only the molar
teeth are represented

Teeth of Troglodytes sivalensis, an extinct anthropoid ape
(Simiidae) ; A, upper right series; the molar teeth were probably
four-cusped ; the last tooth is degenerate in point of size. B,
second left upper molar tooth

Mandible (A) and teeth (B and C), of Dryopithecus fontani, an
extinct anthropoid ape resembling the Chimpanzee (Simiidae).
C, represents diagrammatical ly the number and disposition of
the dental cusps : the transverse ridges resemble those prevalent
in the Cercopithecidae ...•••••

The calvaria of Pithecanthropus erectus seen from above (£ nat.
size)

The calvaria of Pithecanthropus erectus seen from the side (J nat.
size)

PAGE

498

499

500
500
500

502

504

505

506

508

513

INDEX OF ILLUSTRATIONS

XXV

Fig. 322.

Fig. 323.
Fig. 324.

Fig. 325.
Fig. 326.

Fig. 327.

Fig. 328.

Fig. 329.

Fig. 330.

Fig. 331.
Fig. 332.

Fig. 333.

Chart A.

Chart B.

Chart C.
Chart D.
Chart E.

Tracing of the calvaria of Pithecanthropus erectus, to shew the
angle included by the nuchal-plane (N), and the Glabello-
opisthionic line (Gl-Op). N', represents the inclination of the
nuchal plane in Hylobates (Simiidae), and N", the corresponding
inclination in a Papuan skull (Hominidae) : the latter specimens
are orientated similarly, i.e. with the Glabello-opisthionic line
corresponding in position to the calvaria of Pithecanthropus
erectus ............

Two views of the left femur of Pithecanthropus erectus .

The last upper right molar tooth of Pithecanthropus erectus. De-
generacy is denoted by crenation and comparative reduction of
the antero-posterior diameter of the crown, which is markedly
inferior to the transverse diameter ......

The Neanderthal cranium, seen from above : the general features
resemble those of the crania from Spy. (Cf. Figs. 328, 330)

The Neanderthal cranium, seen from the left side: the prominent
brow-ridges and the flattened cranial arc resemble the correspond-
ing features in the Spy crania, (v. especially Fig. 329, and also
332)

Tracing (after Schwalbe) of the outline of the Neanderthal skull:
to demonstrate by means of the angular measurement (d) the
flattening of the cranial arc .......

One of the crania (No. 1) from Spy, seen from above. The cranium
is elongated and post-orbital narrowing is marked

Lateral view of the Spy cranium (No. 1). The prominence of the
brow-ridges is very distinct

The Spy cranium (No. 2) seen from above. Its characters, though
less marked, resemble those of cranium No. 1. (Cf. Fig. 328)

The Krapina skull, in norma vertiealis (after Kramberger)

Tracing of the (reconstructed) Krapina skull, in norma lateralis
(after Kramberger)

Femur (A) of the Spy skeleton No. 1, compared with (B) a recent
human femur (after Fraipont). These femora should be compared
with those of Pithecanthropus erectus (Fig. 323) and of an Orang-
utan (Fig. 202) .

Variation in the Inter-membral Index up to the third month of
infancy

Variation in the Inter-membral Index during the first twenty years
of life

Variation in the Radio-humeral Index

Variation in the Tibio-femoral Index

Variation in the Humero-femoral Index

PAGE

514

515

516

524

525

526

528

529

530
532

532

536

330

332

334

337

339

ADDENDA AND CORRIGENDA.

PAGE

3. In the legend of Fig. 2, for Chap, x., read Chap. xi.

36. For Chap. xvi. read Chap. xvir.

43. For “ Platyrrhine and Catarrhine,” read “ Platyrrhine ” only.

47. Fig. 34. The brain represented here and in Fig. 271 is that of a young male
Gorilla in the Cambridge Collection.

63. Windle and Parsons’ research on the M. biceps femoris anticipated that of
Klaatsch, who made a communication on this subject at the German
Anthropological Society’s Congress at Halle in 1900.

82. To the reference to Chap. xii. the words “ Fig. 172 ” should be added.

93. The organs of the special senses are similarly constructed in the Simiidae
and Hominidae alike. Close similarity in structure and appearance
obtains in such details as the macula and fovea of the retina.

144. Itose’s research was published in the Oenterr. Ungar. VierteljahrsBchrift
fiir Zahnheilkunde, Jahrgang 11, Heft 11. “ Ueberreste einer vorzeitigen

priilactalen, und einer vierten Zahnreihe beim Menschen.”

198. In the legend of Fig. 145, for “ H. Ectoderm,” read “ H. Entoderm.”

204. Deciduoma malignum. The subject thus introduced promises to yield results
of far-reaching importance both for Comparative Anatomy and for Patho-
logy. An admirable paper was published by Adami of Montreal in 1902
( Clinical Journal, June 18th); other and more recent researches, with
bibliographical references, will be found in the Zeitschrift fiir Gcburtshilfe
und Gyndkologie, Band lti. Heft 2, 1904 ; viz. Hammerscklag “ Klinische
und anatomische Beitrage zur Lehre vom Chorionepithelioma,” and
D. v. Yelits, “ Ueber histologische Indicien des Chorionepithelioma
benignum.”

222. After “2 post-glenoid foramen” add “and post-glenoid tubercle; the latter is
large and ape-like in two crania of Tasmanian aborigines, in two crania
of Australian aborigines, in two crania of Bush natives, and a very massive
cranium of Melanesian appearance from New Zealand, all these specimens
being now in the Cambridge Collection. ”

In Fig. 174, the angle 6' is also called the basilar angle of Broca.

248.

ADDENDA AND CORRIGENDA

XXV11

PAGE

281. For “ Eltung ” read “ Elting.”

288. In the legend of Fig. 188, for “ enselline ” read “ ensellure.”

311. Obliquity of the forearm. This is apparently less in the negro than in
the white races.

321. For “Baetz,” read “Baelz.”

357. Fig. 216 was provided by M. Deniker with permission from Messrs W. Scott
and Co.

426. In Figs. 247 — 254 inch, and 259 — 262 incl., the sulcus lunatus is denoted by
the abbreviation S. lun.

462. At the conclusion of paragraph 2, add “ The occurrence of typically Mela-
nesian crania in such widely-separated groups as the Orang-Lant (of the
Malay Peninsula), the natives of Rotuma, and the Bush natives of South
Africa may thus become more intelligible. In the two former instances,
however, actual migration may have taken place.”

505. In reference to Fig. 317, note that a better specimen (at Paris) than that
which is represented, shews that transverse ridges were present in the
lower molar teeth of Mesopithecus, as in those of recent Cercopitheeidae.

510. In footnote 2, line 5, for “ it ” read “ is.”

511. To footnote 2 it should be added that v. Branco has had the boldness to
suggest that the Javan fossil discovered by Dubois was a hybrid.

Legend of Fig. 322 ; in the 3rd line, for N' read N".

514.

ABBREVIATIONS.

The following are some of the abbreviations employed in footnotes :

Linn. Trans. — Transactions of the Linnaean Society.

Proc. Anat. Soc. — Proceedings of the Anatomical Society.

Proc. Zool. Soc. — Proceedings of the Zoological Society.

J. A. and P. 1

J. A. P. V — Journal of Anatomy and Physiology .

Journ. of Anat. and Phys.j
Anat. Anz. — Anatomischer Anzeiger.

Proc. Philad. Acad. — Proceedings of the Philadelphia Academy of Natural
Sciences.

Jahr. der Anatomic — Jahresbericht der Anatomic und Entwichelungsgeschichte.
Bill. Zool. — Bibliotheca Zoologica.

Bull, de la Soc. d’Anthr. — Bulletins de la Soci6t6 d’ Anthropologic de Paris.

Am. Journal of Anat. — American Journal of Anatomy.

Chall. Rep. — Challenger Reports.

Z. fiir Ethn. — Zeiischrift fiir Ethnologic.

Journ. Anth. Institute. — Journal of the Anthropological Institute of Great Britain
and Ireland.

Precis d’A. — Pr6cis d’Anthropologie ( Ilovelacque et Ilamy).

Cat. Mus. R. C. S. — Catalogue of the Specimens in the Museum of the Royal
College of Surgeons , London.

Ergebnisse. — Ergebnisse liber einer Forschungsreise nach Ceylan.

Bull. Am. Mus. Nat. Hist. — Bulletins of the American Museum of Natural
History.

CHAPTER I.

INTRODUCTION.

In entering upon the study of the morphological aspects of
Anthropology it is of the first importance to ascertain and realize
the scope and limits of the subject. This is admittedly a some-
what difficult task, and the following account aims at giving some
general information of an introductory nature.

The use of the term Anthropology is not modern, and when
first employed1 it referred in a general sense to human anatomy
and physiology, the study of which was at the time referred to in
a very elementary stage. In earlier days certain philosophers had
been spoken of as anthropologists, and again in later times, i.e.
in the 18th century, Anthropology was treated (by Kant and
others) as a branch of philosophy, rather than of natural science.
The latter end of the 17th century was a most important epoch in
the history of Physical Anthropology, using the term in the sense
which it has now acquired and which will presently be explained.
It was in the year 1699 that Dr Edward Tyson, a member of
Corpus Christi College, Cambridge, published under the auspices
of the Royal Society a treatise entitled “ Orang-Outang, sive
Homo Sylvestris ; or, the Anatomy of a Pygmie compared with
that of a Monkey, an Ape, and a Man2.”

1 In 1501 by a German, Magnus Hundt, of Marburg.

2 In this work we find described system by system and organ for organ
the comparative anatomy of man and a “ Pygmie.” Upon the evidence thus pro-
vided is based a discussion of the relations of the two forms, the differences as well
as the resemblances of the two animals are taken into due consideration, and the
author sums up to the effect that “our Pygmie is no Man, nor yet the Common
Ape, but a sort of animal between both.” The descriptions, the illustrations, and
the skeleton of the “ Pygmie ” (now in the Natural History Museum, S. Kensington),
shew that it was an immature Chimpanzee.

D. M.

INTRODUCTION

[CHAP.

Without entering upon detailed criticism of this work it may
be said that it constitutes a most remarkable anticipation of
modern methods of research, and still serves as a model for investi-
gations into the structure of Man and Apes (Fig. 1). Nevertheless

Fig. 1. Drawing of a dissection of the genito-urinary system of a Chimpanzee.
From Tyson’s “Orang-outang, sive Homo Sylvestris'. Or, the Anatomy of a
Pygmie.” London, 1699.

although so important in these respects the work was not described
as one on Anthropology, nor is it certain that Tyson made use of
the term in connection with it.

The 18th century in turn affords several notable names in
the history of Anthropology. The chief contributors to the sub-
ject were Linnaeus, Buffon, Camper1, Lamarck, and Blumenbach,

1 Born in 1722 at Leyden, Camper had reached the age of sixty-seven at the time
of his death at the Hague. But for the work of Tyson, that of Camper would hold
the place of honour as anticipating the soundest and most productive methods of
modern physical anthropology. The most important of Camper’s writings in this
connection deal with the comparative anatomy of the orang-utan (a chapter being
devoted specially to comparison with human anatomy), with the significance and
origin of pigmentation in the negro races, and finally with a method of the com-
parative study of skulls, based upon the principle of projections, i.e. the comparison

INTRODUCTION

of whom the first is distinguished by having- deliberately included
Man with other animals in his system of classification. Buffon
studied the varieties of Mankind, and is credited with the applica-
tion of the word “ race ” to the several modifications of the human
type. Lamarck’s name is inseparably associated with the enuncia-
tion of a theory accounting for the differences observed in the
forms of animals.

Finally Blumenbach is distinguished particularly by his studies
in comparative human craniology (cf. Fig. 3), a science of which
he may be said to have laid the foundations1.

of forms and contours drawn in rectilinear projection, so as to eliminate errors due to
perspective such as occur when the object is observed in the ordinary way. In the
latter treatise Camper defines and explains the use of the facial angle (cf. Fig. 2),
which has subsequently remained.

Fig. 2. Drawings of the head and skull of a young Orang-utan, and of a negro
to shew the method of determining the facial angle of Camper (cf. Chap. x.l. From
Camper’s original memoir.

1 So important are Blumenbach’s contributions to Anthropology that a few notes
on his work may not be out of place in this connection. Born at Gotha in 1752
Blumenbach studied successively at Jena and at Gottingen, at which latter Univer-
sity be obtained a professorial chair : and at Gottingen Blumenbach died in 1840.
Three characteristics seem to be prominent before all others in the character of this
remarkable man. His extraordinary versatility in scientific pursuits has rarely

1—2

INTRODUCTION

[CHAP.

This growing tendency to study Man as a zoological form shews
the trend towards the modern conception of Physical Anthropology.

Fig. 3. Blumenbach’s "norma verticalis” of three crania ; A, an “Ethiopian”;
B, a Georgian woman ; C, a Tunguse. The different degrees to which the maxilla
and tlie zygomatic arches project beyond the periphery of the cranial bones is to be
noticed. (The figure is copied from that illustrating Blumenbach’s works as trans-
lated by the Anthropological Institute.)

Another important epoch in the history of our subject is the
earlier half of the 19th century ; and it is particularly marked by

been surpassed, even in the fatherland of Goethe, v. Helmholtz, and Virchow.
Scarcely less impressive was his enormous range of literary acquaintance. A third
point is that he was eminently a laboratory worker (sesshaft, as the Germans style
it), for he travelled but little.

Blumenbach’s principal contributions to science consist of a treatise on the
“ Natural Varieties of the Human Species ” and of numerous craniological descrip-
tions, to which must be added certain essays on the Natural History of Man,
including an anatomical comparison of Man with other animals. And the chief
advances determined by these researches may be summarised as follows:

(1) The employment of the word “ anthropology ” as descriptive of morpho-
logical studies.

(2) Recognition of the fact that no sharp lines demarcate the several varieties
of Mankind, the transition from type to type being imiJerceptible.

(3) The clear enunciation of a classificatory scheme of the varieties of Mankind,
admittedly arbitrary, but devised with the object of facilitating study : the classifi-
cation was based on considerations of the characters of the skin, the hair, and the
skull.

(4) Recognition of the influence of external causes in producing and perpetuating
variations in animals, including Man ; recognition of the origin of varieties through
“degeneration”; Blumenbach thus very nearly anticipated some important dis-
coveries reserved for Darwin at a later date.

INTRODUCTION

the foundation of societies for the scientific study of Man. The
societies in question were founded in several countries, among
which France and our own country took the lead. But the sub-
ject still remained in an undifferentiated condition, and the
distinction between the studies of mental and physical attributes,
or of nations and races, was not yet clearly marked. Such
subdivision and specialization of study do not occur in the earlier
phases of the life-history of a science, and Anthropology formed
no exception to the general rule.

Anthropological Societies were founded, as has been mentioned,
early in the 19th century, at an epoch when Hebraic cosmology
was very generally and literally accepted. Against such literal
acceptance there were not lacking protests ; the progress of
zoological study (perhaps especially the results of observations
on the geographical distribution of animal forms) had cast
doubt on that part of the account relating to animals other
than Man, just as the birth and progress of scientific geology
rendered necessary a revision of the opinion commonly held as
to the history of the earth. These new creeds had not yet
however gathered the force they were subsequently to acquire,
and in particular the inferences drawn from them were not
generally recognised as having an application to the special case
of the origin of Man. None the less, certain French writers of the
18th centuiy (Buffon and Lamarck) had clearly suggested the
possibility of the evolution of new species by the transformation of
pre-existing forms of life, and had applied this reasoning to the
case of Man in common with other animals. By so doing they
kindled a spark of controversy which, after smouldering for half
a century, was destined to break out as a veritable conflagration
soon after the founding of the Societies of Anthropology to which
reference has just been made. The labours of those Societies
received thereby a stimulus the importance of which can hardly be
over-estimated. But the point which it is here desired to empha-
size is, that the early work of the Anthropological Societies con-
sisted largely in the study of the outward appearance and social
status of the various races of Man; when to this there is added
the study of racial differences in human crania, an idea will be
formed of the nature of Anthropology in the earlier decades of the

6 INTRODUCTION [CHAP.

19th century. The problems of the origin of Man and of his
relation to other animals still remained to be added.

Anthropology thus received a wider application than here-
tofore, and further, it is to be noticed that two men in particular
(Darwin and Huxley) were instrumental in thus extending
and rendering more precise the morphological aspect of this
subject. The chief merits of Darwin in this connection may
be summed up in the statement that he not only suggested the
principle of Evolution as an explanation of the existence of the
many varied animal forms, but brought it vividly before a very
large section of the public ; that he on the one hand indicated a
possible explanation of the method of Evolution and on the other
hand demonstrated that the reasoning involved is applicable to

Fiv 4 The longitudinally-bisected skull of a male Gorilla: the line B.Pr.N
represents the spheno-ethmoidal angle of Huxley, here equal to two right angles
or 180°.

INTRODUCTION

Man equally with other animal forms1. This work was very
appropriately supplemented by
that of Huxley, who enunciated
clearly the conclusions as to the
relations of Man to other ani-
mals, which would be arrived at
by the application of the line of
argument laid down by Darwin.

Huxley’s lectures2 given in
1863 are still the best introduc-
tion to this part of the subject.

It is impossible here to
enter into an historical account
of the vicissitudes of what were
at that date newly-published views as to the origin of Man: nor is it
possible in this place to do more than mention the names of the chief
contributors to the progress of the same in receiving acceptance. It
is however important to notice that Anthropology soon proved to be
a subject capable of almost indefinite extension. From the study
of the external appearance of Man in all his varieties, the attention
of students was turned, through the causes just mentioned, to the
investigation of the structure of the human body, in other words to
the study of Human Morphology. It is preferable in this connection
to speak of Human Morphology rather than of Human Anatomy,
for the former term implies the comparison of the architectural form
of the human frame with those of other animals.

Not that the study of Human Morphology was a newly-
discovered field for activity ; and it is here that the interest that
attaches to Tyson’s work becomes manifest ; for the keynote of the
treatise to which reference has been made is the morphological
aspect of anthropology as studied by means of a detailed comparison.
Moreover, as we have seen, Peter Camper of Amsterdam had followed
Tyson with a very remarkable contribution to the study of the
skull. On the embryological side, Meckel and v. Baer in the early
part of the 19th century had made discoveries of fundamental
importance for the progress of the science.

1 Cf. Darwin, On the Origin of Species die. : and The Descent of Man.

2 “ Man’s Place in Nature.” Similar lectures were given by Carl Vogt in Geneva.

skull of an aboriginal native of Australia,
with the lines shewn by which Huxley’s
spheno-ethmoidal angle (8) is included (viz.
BPr, and NPr).

INTRODUCTION

[CHAP.

New, however, was the widespread recognition, first that
the study of the origin of Man now demanded the attention
and the interest of students of natural science, and secondly, that
this problem, of which the solution had appeared so hopeless, might
now be attacked by the same methods as were being applied with
success to unravelling the origins of other members of the Animal
Kingdom1.

The range of anthropological studies was in this way very con-
siderably enlarged about the middle of the 19th century. Soon
there came a further extension : for the study of human crania
(which has already been mentioned as forming a subsection of
Anthropology from the time of Blumenbach) was now energetically
pursued in various European countries. In this connection the
names of Retzius, Huxley, Lucae, Virchow, Schaafhausen, Flower
and Turner are of note, but above and beyond all these stands the
French observer Paul Broca, whose work has had an almost
incomparable influence on the study of Craniology2. This study

1 The ancestry of the horse as demonstrated by Huxley is a good example in
point.

2 Paul Broca was born in 1824. Educated as a surgeon, he not unnaturally
first published work dealing with surgical topics, such as the surgery of aneurism.
In 1859 Broca published a contribution to biological literature entitled “Hybridity,”
pointing out the interest of the phenomena of hybridity in connection with the
stability and fixity of animal species. In this work the special case of man is
discussed, and doubt cast on the occurrence of Eugenesis, or the fertility of the
offspring of individuals of strongly contrasted race; these doubts have been resolved
in the negative.

In the same year (1859)

Broca published the first of
a long series of works upon
the prehistoric inhabitants of
Western Europe ; the first
contribution dealt with the
Ethnology of France, shew-
ing the effects of invasions
upon the primitive autoch-
thones of that land. Numer-
ous essays on the human
skeleton and particularly upon
the skull followed. Attention
was then diverted to the soft
tissues, and like Blumenbach,

Fig. 6. Left cerebral hemisphere of an ab-
original native of Australia. “Broca’s convolution ”
is indicated by the shading.

INTRODUCTION

has been spoken of as distinct from that of Human Morphology,
but it is important to notice that the newcomers in this field
recognised that Craniology is to be regarded as essentially a branch
of Human Morphology, and that only in this way can it lead to
reliable results : the omission to recognise this important fact has
led to many misconceptions and to the vain expenditure of much
misdirected energy in Craniology.

But this does not complete the account of the extension of
territory claimed by our subject. We must leave for the moment

Broca worked out an anatomical comparison (Parallele, as it is termed by French
writers) of Man and the Apes. Recognising the importance of the brain in the
animal economy Broca devoted much time to its study. His contributions to
the subject of Aphasia, and
his recognition of the locali-
sation of the faculty of speech
in the convolution which now
bears his name (the inferior
frontal convolution of the left
cerebral hemisphere), are well
known (ef. Fig. 6). And
though his conclusions have
not been altogether borne out
in detail by the results of later
workers, Broca’s contributions
to the morphology of the brain
certainly place him among the
foremost pioneers in that field.

Not the least of Broca’s
merits is his recognition of the
necessity of accurate methods
of comparison, and this led to
his devising a multitude of
delicate instruments of which
the best known is perhaps the
stereograph (cf. Fig. 7), a me-
chanical apparatus for tracing
contours which can subse-
quently be superposed and
accurately compared. Broca’s
extension of the use of “in-

Fig. 7. The stereograph of Broca : a mechanical
device for producing rectilinear projection drawings
of crania or similar objects. For further description
see Chapter x.

dices ” in craniological studies,

a method due to the elder Retzius, is an important feature of his works, but is not
a matter of such lasting or fundamental importance in regard to his scientific
contributions as a whole.

INTRODUCTION

[CHAP.

the various problems grouped under the general heading of
Morphology and turn to another aspect of the study of Man.
Anthropology being now regarded as the Natural History of Man,
it became necessary to investigate not only his bodily structure but
his intellectual powers and their manifestations: not only these, but
even the origins of human society, and of arts and sciences of
whatever kind, were gradually added to the list, so that Anthropo-
logical literature now deals with a variety of subjects so diverse as
the studies of languages, of the special senses in civilized and
savage races, of decorative art, of the origins of religion, of picture-
writing, of children’s games, of keramics, of metallurgy, and of
midwifery. In fact, Anthropology is no longer a single science but
a group of these, and consecpiently, to use the simile so ably put
forward by Professor Tylor, can be well compared to the frame used
by mountaineers for the purpose of supporting a miscellaneous
load. The convenience of the frame more than compensates for
the slight additional weight imposed by it.

It is appropriate to remark in this connection that the
theory of Evolution has proved to be of the utmost utility in the
study, not of Animal Morphology alone, but of every one without
exception of the above-mentioned subjects, widely different though
they may at first sight appear to be. In every one without
exception may be found numerous instances in which the doctrine
of Evolution has given the clue to the interpretation of a series of
observations, and has afforded such a demonstration of otherwise
unsuspected relations between them as no other known principle
could have possibly furnished1.

The foregoing notes may serve to give an idea of the protean
nature of Anthropology ; a subject which the individual will strive
in vain to grasp fully in the course of his natural lifetime. It is
therefore necessary to limit one’s efforts to a certain region or
section, and the section which will be the subject of consideration
in the following chapters is that to which reference has been
already made, viz. the morphological aspect of Anthropology ; in-
cidentally, however, it will be necessary to refer to slightly different
branches of the subject.

1 For examples consult Haddon, The Evolution of Decorative Art ; Balfour,
Evolution in Art.

INTRODUCTION

The following aims may therefore be proposed as falling
within the scope of this enquiry. In the first place, the attempt
must be made to realize the position occupied by Man in the
animal kingdom : and secondly, enquiry must be made into the
nature of the ancestors of Man. Finally, we may be in a position
to discuss the question whether the series of animal forms which
has produced Man has now reached its termination or not.

In connection with the first two questions, the following main
paths lie open. It must be repeated that the study of Morphology
by means of Comparative Anatomy is the first step in such an
enquiry.

The second line of enquiry is closely allied to the preceding,
and consists in the study of Morphology by means of Embryology1.

A third line of research is nearly connected with the other
two; this is the study of Variations, both of outward appearance
and inward structure.

A fourth method, which has been found useful in other cases
but is not specially applicable to that of Man, is the study of
Geographical distribution. It will not be further mentioned at
present.

A fifth method, more closely allied to the first (that of
Comparative Morphology) than to any other, involves the in-
vestigation of the characters of such fossil animals as may be
supposed to have figured in the ancestral history of Man and
his nearest allies among the animals still in existence. This
section of the science of Palaeontology claims much attention
in the attempts to solve the problems of our subject.

Having discussed the general position of Man in Nature, it
will be necessary to consider the various human races, and to
enquire whether some of those races are to be regarded as
morphologically inferior to others, and especially whether the
races which are commonly accounted as lower in the scale of

1 Related to this second line of enquiry is the study of the post-natal stages
of development, in other words, the study of child-life and of children. In
accordance with the general rule that the individual reproduces in his life-history
the successive stages (or the principal ones at least) by which his species attained
its position in nature, it is argued that the immature human individual will afford
some suggestions as to the nature of the latter stages of human evolution.

INTRODUCTION

[CHAP. I

civilization and culture are also inferior in morphological status.
Should this be established, it will next be necessary to ascertain
whether such morphologically inferior forms can be considered as
representatives of the generalized human ancestors. We thus
enter on a division of the second great question, viz. that of the
appearance and nature of the ancestral animal-forms which led
up to Man.

The foregoing notes will give an idea of Human Morphology
as studied from the standpoint of Anthropology ; the immediate
subject of consideration is thus seen to be the place of Man in
the zoological series, or animal kingdom. Without entering into
an elaborate exposition of various types of life, it will suffice to
say that judged by his structure Man is undoubtedly a vertebrate
animal of the class Mammalia. Starting from this point, it is
proposed to briefly study the characteristics of Mammals so as
to understand how it is that this statement as regards Man can
be justified. The following chapter will accordingly deal with
Mammalia in general.

SECTION A.

COMPARATIVE ANATOMY AND MORPHOLOGY
OF EUTHERIAN MAMMALS.

CHAPTER II.

THE MAMMALIA: AND THE APPLICATION OF THE METHODS
OF MORPHOLOGY TO THEIR CLASSIFICATION.

It is necessary at the outset to give a brief description of the
animal forms with which we are chiefly concerned, and to treat of
them in a methodical manner.

Man’s nearest relations are members of a class of vertebrate
animals called Mammalia. Of this class three sub-classes are
recognised, and it must be noted that the members of two of
these three sub-classes are comparatively few in number and not
natives of Europe ; an example of one of these sub-classes is the
Australian spiny ant-eater, and the kangaroo is an example of
the other. The third sub-class contains a larger number of animal
forms, and to it belong all our indigenous mammals.

One can imagine several ways in which the various mammals
might be grouped for purposes of description : for instance they
might be arranged according to their geographical distribution,
or else according to the nature of their food, or again according
to their habits : and the first-mentioned means of distinction
might be called a climatic criterion, which would for instance
distinguish arctic animals from those living in tropical latitudes,

THE MAMMALIA

[SECT. A

while the second means of distinction (diet) would be called a
physiological criterion. Thus it is that we are compelled at the
outset to state clearly the basis upon which we proceed in a
classification. In the present case the basis is Morphology, and
our criterion is the criterion of structure. In this classification,
animals will be considered as more or less closely related, according
as their structure is more or less similar in its details. It is
necessary to enter into details, because the very fact of the name
“vertebrate” being applicable to all the animals about to be
considered, implies that they possess one general morphological
character in common, and indeed that they are constructed upon a
similar plan. Further, although this is an anticipation, it may
be said that when the criterion of structure is employed, the
determination of the relations of Man in the Class Mammalia is
more easy than when other criteria are made use of. On this
subject the verdict of Morphology is clear and unhesitating.

It is further to be noted that the most primitive morpho-
logical type of mammal is as a rule, though not always, the
most simple; and the less primitive is often, though by no means
always, the more complex in construction.

The comparative method of study is to be applied to all the
mammalian forms, and when the test of Morphology is applied to
Man himself it will be found as has been said that his relative
position is well defined. This application of the principles of
Morphology to the special case of Man constitutes the essence
of Physical Anthropology.

In connection with what have just been referred to as the
principles of Morphology, the following point is of interest and
importance. It will be remembered that the vertebrate body
is composed of a number of very different parts, and that
although these are demonstrably similar to one another, in-
asmuch as they all possess cellular structure, yet the cells have
undergone specialization in several different directions, with the
consequent production of a number of tissues from which have
been built up systems familiar to us as the skeletal system,
digestive system, and so on. It is indeed an important con-
sideration in Vertebrate Morphology, that specialization of .
primitively similar cells has occurred, resulting in the production

THE MAMMALIA

CHAP. Il]

of tissues and systems. From the general consideration of the
vertebrate body it is however necessary to pass to that of the
several tissues and systems, and here it is that the point in
question presents itself.

In the study of the morphology of the various systems, we
find that each is constructed on a certain plan so that each may
be referred to a fundamental, primitive, or type-form. Thus the
primitive forms of the central nervous system, or of the skeletal
or arterial systems, are common expressions. Each system of a
given animal reveals a more or less altered representation of that
primitive form. Now the difficulty alluded to consists in the fact
that in such a given instance (and this is especially true of
Mammals), though each system will be found to represent a
modified form of the primitive type, yet the amount of modifica-
tion undergone is different for each system. Thus an animal may
possess a nervous system of very primitive, i.e. slightly modified,
form together with an extremely modified integumentary system.
It follows therefore that in assigning a place in the classification
to a given animal, attention must be paid to the morphology of
each and every system, and a position must only be assigned to it
after a final summary of all the evidence has been made. Thus
an animal like the hedgehog presents us with the morphological
combination of a brain of simple conformation, together with
an integument of very modified character. Taking other mor-
phological points in the anatomy of the hedgehog, the general
balance of the summing up of evidence indicates that on the whole
this is a little modified, i.e. a comparatively simply-constructed
animal, which is the result one would have arrived at from the
study of the brain alone, though opposed to the indication that
would be afforded if the observation had been confined to the
integument.

dhe disadvantage attendant on the employment of a single
j criterion, such as the conformation of a single organ or system,
may be further illustrated by the example of the genitalia
1 in Man. Judged by the single characteristic of the morphology
of the genital organs, Man differs more widely from Woman
than from an individual of his own sex in such a comparatively
lowly form as a shrew-mouse. It follows therefore that in-

THE MAMMALIA

[SECT. A

ferences from observations on various systems and organs must
be introduced into what may be called the morphological balance
sheet, due allowance being made for conditions determined by
sex and by age.

The foregoing remarks will serve to indicate the importance of
taking into consideration the evidence given by several systems
and of summing up the results thus obtained.

It will be further seen that the determination of the value to
be attached to the evidence from various systems is to a large
extent a matter of agreement or convention. In returning to the
subject of the Classification of Mammals1, we must then first
consider the combination of morphological characters which entitle
the animal possessing them to be ranked as a mammal. In view
of what has just been noted as regards the different systems, it
will not be a matter of surprise that the characters selected are
taken from several, and not all from any one system.

The Distinctive Characters , and the Classification of Mammals \

The Mammalia are air-breathing vertebrates, with warm blood,
and with an epidermal covering in the form of hairs.

I. The bodies of the vertebrae are in nearly all mammals
ossified each from three independent centres, one of which developes
into the centum proper, while the others give rise to two discs of
bone — the epiphyses. Also characteristic of the spinal column of
mammals are the discs of fibro-cartilage, termed intervertebral
discs, which intervene between successive centra.

II. The skull has two condyles for connection with the atlas,
instead of the single condyle of the Sauropsida (Birds and Reptiles);
and the lower jaw articulates with the skull in the squamosal region
without the intermediation of the separate quadrate element
always present in that position in Birds and Reptiles.

1 Notice that the character, viz. the nutrition of the young by the secretion of
milk-glands, which has given the Class its name, is not a morphological, but a
physiological feature.

2 Owing to the courtesy of authors and publishers, the classification of the
Mammalia as given by Messrs Parker and Haswell in their Text-book of Zoology,
Vol. n. (Macmillan), is here available.

THE MAMMALIA

CHAP. Il]

III. Each of the long bones of the limbs is composed (in the
young condition) of a central part or shaft, and of terminal epi-
physes, the latter only becoming completely united with the shaft
at an advanced stage. The ilio-sacral connection is pre-acetabular:
there is a cruro-tarsal joint.

‘Sx^uarrjo&al
,'Jucjal (njalar)
— Quadrate
ijdiUe

Fig. 8. Fig. 9.

Fig. 8. Occipital view of the cranium of a Bird (Larus) ; to shew the single
median occipital condyle, and the intervention of the quadrate bone between the
mandible and the cranial wall.

Fig. 9. Occipital view of the cranium of a Dog ; to shew the twin occipital con-
dyles, and the direct articulation of the mandible with the cranial wall, without the
intervention of a quadrate bone.

IV. In the Mammalian pectoral girdle, the coracoid of Birds and
Reptiles is usually represented only by a vestige or vestiges which
unite with the scapula in the adult. Figs. 10, 11, and 12.

Fig. 10. Shoulder girdle of a Reptile (Iguana) ; to shew the elements of the
girdle in a comparatively undifferentiated condition.

D. M.

THE MAMMALIA

[SECT. A

Fig. 11. Shoulder girdle of a Prototherian Mammal (Echidna) ; to be compared
with Fig. 10. Several of the primitive constituent elements of the girdle are still
distinct.

Fig. 12. Shoulder girdle of an Eutherian Mammal (Man) ; to shew the reduc-
tion in number of elements remaining distinct.

V. Mammals are typically diphyodont, i.e. have two sets of
teeth — a milk or deciduous set, and a permanent set : some are
monophyodont, i.e. have only one set. The teeth are thecodont,
i.e. the base of each tooth is embedded in a distinct socket or
alveolus in the substance of the bone of the jaw : and nearly
always the teeth in different parts of the jaw are clearly distin-
guishable by differences of shape into incisors, canines, and grinding
teeth, i.e. are heterodont ; in some instances the teeth are all alike
(homodont).

VI. A cloaca is absent, except in the Prototheria.

VII. A moveable plate of cartilage — the epiglottis — repre-
sented only by a rudiment in some Amphibia and Sauropsida —
overhangs the slit — commonly called glottis — leading from the
pharynx into the cavity of the larynx.

VIII. A partition of muscular fibres usually with a tendinous
centre — the diaphragm — divides the cavity of the body into two

CHAP. Il]

THE MAMMALIA

parts, an anterior — the thorax — containing the heart and lungs,
and a posterior — the abdomen — containing the greater part of the
alimentary canal with its associated glands — the liver and pancreas
— and the renal and reproductive organs.

IX. The lungs are freely suspended within the cavity of the
thorax.

X. The heart is completely divided into two halves — a right
and a left — between which there is no aperture of communication.
Each half consists of an auricle and a ventricle, opening into one
another by a wider opening, guarded by a valve composed of three
membranous cusps on the right side, two on the left. The right
ventricle gives off the pulmonary artery : the left gives off the
single aortic arch, which passes over to the left side, turning round
the left bronchus in order to run backwards as the dorsal aorta : it
therefore represents the left aortic arch of Reptiles.

XI. The blood is warm. The red blood corpuscles are non-
nucleated and usually circular.

XII. The two cerebral hemispheres, in all but the Prototheria
and Metatheria, are connected together by a band of transverse
fibres — the corpus callosum — not represented in the lower verte-
brates. The dorsal part of the mid-brain is divided into four optic
lobes — the corpora quadrigemina. On the ventral side of the hind
brain is a transverse band of fibres — the pons varolii — by which
the lateral parts of the cerebellum are connected together.

XIII. The ureters (except in the Prototheria) open into the
bladder. Mammals are all, with the exception of the Monotremes,
viviparous.

XIV. The foetus is nourished before birth from the blood-
system of the parent through a special development of the foetal
membranes and the lining membrane of the uterus, termed the
placenta. After birth the young mammal is nourished for a longer
or shorter time by the milk or secretion of the mammary glands of
the parent.

Such are the characteristics common to all mammals. The
animals presenting these characters have been classified as follows.

THE MAMMALIA

[SECT. A

CLASSIFICATION.

CLASS MAMMALIA.

Sub-Class 1. Prototheria.

Order Monotremata.
Sub-Class 2. Theria.

Section A. Metcitheria.

Order 1.

Polyprotodontia.

Order 2.

Diprotodontia.

Section B.

Eutheria.

Order 1.

Edentata.

Order 2.

Cetacea.

Order 3.

Sirenia.

Order 4.

Ungulata.

Order 5.

Carnivora.

Order 6.

Rodentia.

Order 7.

Insectivora.

Order 8.

Cheiroptera.

Order 9.

Primates.

Without entering into a detailed description of the characters
of the several Orders, it will suffice to enumerate those of the
Sub-Classes and of the Sections.

SUB-CLASS I. PROTOTHERIA.

1. The vertebral centra lack epiphyses, or these are only
imperfectly developed.

2. The bones of the skull coalesce early, by the obliteration of
the sutures (the skull thus resembling that of birds).

3. A large coracoid, articulating with the sternum, is present.

4. A T-shaped episternum is present.

CHAP. Il]

THE MAMMALIA

5. Two epi-pubic bones are present.

6. A cloaca is present, into which ureters and urinary
bladder open separately.

7. The corpus callo-
sum is not developed in
the brain.

8. The oviducts are
distinct throughout.

9. The mammary
glands are devoid of teats.

10. The ova are mero-
blastic, and are discharged
in an early stage of their
development, enclosed in
a tough shell.

rp, • Q 1 l , Fig. 13. Shoulder girdle of a Prototherian

lhis out) -Class com- Mammal (Echidna); to be compared with

prises a single living Fig. 10. Several of the primitive constituent
& ° elements of the girdle are still distinct.

Order, the Monotremata,

including the Duck-bill or Platypus (Ornithorhynchus), and
the Spiny Anteater (Echidna), together probably with an imper-
fectly known and extinct (Secondary and early Tertiary) Order,
the Multi-tuberculata.

SUB-CLASS II. THEBJA.

1. The vertebral centra possess distinct epiphyses.

2. The skull bones do not in most cases completely coalesce,
most of the sutures remaining distinguishable throughout life.

3. The coracoid is vestigial.

4. The epistemum is incorporated in the substance of the
presternum (Gotte).

5. The cloaca is not present (Gadow restricts this statement
to males).

6. The oviducts are united in a longer or shorter part of their
course.

THE MAMMALIA

[SECT. A

7. The mammary glands are provided with teats.

8. The ova (except in some members of Section A of the Theria)
are holoblastic, and the early development of the young takes place
in the uterus.

9. The epi-pubic bones and the corpus callosum are variable
in their occurrence.

SUB-CLASS THERIA. SECTION A. METATHERIA OR
MARSUPIAL1A.

1. Theria, in which the young are born in a comparatively un-
developed state, and are sheltered during their later development
in an integumentary pouch, the marsupium.

2. In the skull, the tympanic cavity is partly bounded by the
alisphenoid ; the jugal (malar) bone furnishes a contribution to
the floor of the glenoid cavity.

Lacr^rrjal Gorje. Malar

Glenoid j*ossa
fyrrjparjit bop«
Uli&pI^t-yDid

Fig. 14. Cranium of Sarcophilus, a Metatherian or Marsupial Mammal ; the
shaded area denotes the extent of the alisphenoid bone along the cranial wall ; note
the extent backwards of the malar bone, and the extent forwards of the lacrymal
bone. Cf. Fig. 15.

3. Epi-pubic bones are present and well developed.

4. A single sphincter muscle surrounds both anus and uro-
genital aperture.

5. The corpus callosum is absent.

G. The placenta, when present, is functional for only a short
period.

The Metatheria (or Marsupialia) are divisible into two Orders,
distinguished principally by the characters of their dentition,
particularly of the incisor teeth. There is thus the Order Poly-
protodontia, whose members have numerous (more than three on
each side) incisor teeth. The Opossums belong to this Order. The
second Order (Diprotodontia) possess not more and usually fewer
than three incisor teeth on each side. The Kangaroos are examples
of this Order.

CHAP. Il]

THE MAMMALIA

SECTION B. EUTHERIA.

1. Theria having no marsupium. The young are nourished
in utero for a considerable period, through the agency of a
placenta.

2. In the skull, the alisphenoid does not contribute to the
wall of the tympanic
cavity; nor does the
jugal (malar) (except in
Hyracoidea and some
Rodentia) contribute
to the floor of the

cavity.

3. No epi-pubic
bones are present.

4. The anus and
urogenital apertures
are not surrounded by
a common sphincter.

5. A corpus callosum is present.

The Eutheria can be divided into at least nine Orders dis-
tinguished by the various combinations of morphological characters
enumerated in the following scheme.

Order 1. Eutheria, in which the teeth are absent in the adult
or are imperfect ; the sacral vertebrae are frequently in excess
of the number usual in other orders. The coracoid process is
usually relatively larger than in other Eutheria, and does not
become completely fused with the scapula. The organisation of
the brain is very variable. Edentata.

Order 2. Aquatic Eutheria with large head, fish-like body
devoid of hairy covering, the pectoral limb paddle-like, the pelvic
limbs absent, and with a horizontal caudal fin. The clavicles
(collar bones) are absent, and the pelvis is vestigial. Teeth may
be absent and replaced by sheets of baleen (or whalebone). The
conformation of the nostrils and of the larynx is peculiar.
Cetacea.

Lacr'jrpal kope

-Glerjoid |ossa

boqe

Malar (bulla)
borje

ftllSpbjepoid

Eig. 15. Cranium of an Eutherian Mammal
(Dog) ; for comparison with Fig. 14 ; note the
smaller extent of the alisphenoid (shaded), the malar
and lacrymal bones.

THE MAMMALIA

[SECT. A

Order 3. Aquatic Eutheria with moderate-sized head, with
porpoise-like body covered with a scattered covering of hairs : the
pectoral limbs are paddle-like, the pelvic limbs absent. The
clavicles are absent and the pelvis is vestigial. Teeth are present,
and the palate bears rugose horny plates. The larynx is not
modified as in the Cetacea. Sirenia.

Order 4. Terrestrial, chiefly herbivorous Eutheria, with hairy
covering abundant or scanty ; the terminal phalanges of the digits,
upon which the weight of the body usually falls, nearly always
invested with solid horny hoofs. The clavicle is absent. The
teeth are heterodont and diphyodont; the scaphoid and lunar
bones of the carpus (wrist) are always distinct. The digits are
often reduced in number. Ungulata.

Order 5. Eutheria, chiefly carnivorous, with furry integument :
digits in manus and pes never less than four, and all provided
with claws more or less retractile. The clavicle is variable in its
presence, but it is never complete. The teeth are heterodont and
diphyodont. The scaphoid and lunar elements of the carpus
(wrist) ai’e always united; the brain usually highly developed.
Carnivora.

Order G. Vegetable-feeding Eutheria, mostly small in bulk,
with furry or spiny integument, clawed digits and usually planti-
grade limbs. The dentition is heterodont and diphyodont, and
the form of the incisors is chisel-like : these teeth grow from
persistent pulps. Rodentia.

Order 7. Insectivorous Eutheria with nose usually prolonged
into a short soft muzzle ; with furry or spiny integument, clawed
digits, and usually pentadactyle plantigrade limbs. Clavicles are
present. The dentition is heterodont and diphyodont, and the
molars have pointed cusps : incisors are never fewer than two in
the lower jaw on each side. The brain is very simple in con-
formation. Insectivora.

Order 8. Eutheria in which the pectoral limbs are modified
to form wings, the bones being greatly elongated so as to support
a broad web of skin extending to the hind limbs posteriorly.
The ulna is vestigial, the clavicles well developed. Cheiroptera.

CHAP. Il]

THE MAMMALIA

Order 9. Eutheria with prehensile limbs (adapted to arboreal
life), the thumb and great toe being more or less completely
opposable to the other digits. The digits are nearly always five
in number, and are provided usually with flat nails : the clavicles
are well developed. The brain is variable, but may present high
conditions of development of the cerebral hemispheres. Primates.

It is to be remarked that although numbered from 1 to 9, it
does not follow that this arrangement places the various Orders
in sequence according to their morphological status. It is an
extremely difficult question to decide which is to be regarded
as occupying the highest morphological place : nor are the rela-
tions between the various Orders very clear. The Insectivora
have primitive characters. The Edentata (Anteaters, Armadillos
and the Earth-pig) seem to stand apart and in a somewhat inferior
position1. The Rodentia are also to a considerable extent isolated.
On the other hand the Cetacea and Carnivora seem distantly con-
nected, as do the Sirenia (Manatee and Dugong) and Ungulata :
while the Insectivora, Cheiroptera, and Primates shew marked
signs of affinity with one another2.

The foregoing classification is found to be generally useful,
and applicable to the great majority of mammals. It cannot be
too clearly stated that it is after all largely conventional,
although based on the observed facts of animal structure ; but the
advantage conferred by the mere fact that we can classify mammals
is great, for it enables us to compare their forms and characters
much more easily than if they were not susceptible to reduction
to such order. But like conventional systems of other kinds, it
has its limits ; in other words, it does not apply to every animal.
For there are animals which, when examined in the light of
morphology, and the morphological summary is made, prove hard
to fit into this classification. When we meet with such an
instance, we should therefore remember that it does not prove
that the classification is bad or deceptive, but it shews rather that

1 Judged by the single criterion of brain-formation, this judgment appears from
the researches of Elliott Smith (Linn. Trans, vn, Ser. 2) to need revision ; for the
brain in some Edentata is more highly developed than in certain mammals
commonly regarded as their superiors.

2 Cf. Flower, Osteology of the Mammalia.

THE MAMMALIA

[SECT. A

animals have been evolved without regard to any such conven-
tional system of classification. Indeed on the hypothesis that the
method of the origin of species is an evolution, it follows quite
naturally that animal forms should merge into one another by
imperceptible gradations, and that classification, or grouping in
classes, is actually only possible in view of the fact that large
numbers of animal forms have failed to maintain their places in
the struggle for existence. Had they not failed, it is possible
to imagine a demonstration-series of animal forms ranging from
the Amoeba to Man without any break or interruption. As it is,
the series is discontinuous and incomplete, and the systematist
seizes on isolated groups, giving each a special name in his
classification. And what of the animals between these groups ?
It may be repeated that some, having failed in the struggle for
existence, can only be directly known to us by such of their
remains (and they are not many) as have been preserved in a
fossil form. The skeletal parts only are as a rule thus preserved,
and this shews incidentally the importance of osteology in morpho-
logical study. These are the animal “ links ” which have been
referred to as “ missing.” A few intermediate forms have persisted
down to our time, and these are the animals to which it is hard
to assign a definite position in the system of classification which
has been described.

It should be further remembered that though in an uniform
linear chain all the links are of equal value, yet in the variable
series of animals known to us, such isolated links rqay be of very
different significance, the difference depending on the groups of
animals connected by the link, whether the latter be known in
the fossil or recent state. Moreover the metaphor of a linear
chain is not so exact as that of a sheet of chain-armour in which
a single link may bring three or four other links into mutual
relation.

To take some examples, there may be cited such animals as
the Archaeopteryx, a form which suggests a link between the
Class of Birds and the Class Reptilia : the Galeopithecus volans,
which occupies a corresponding position, but merely with regard
to Orders (viz. the Insectivora, Cheiroptera and Primates) of the
Class Mammalia : the Cynopithecus monkey of Celebes, which

CHAP. Il]

THE MAMMALIA

connects the Genus Macacus with the Genus Cynocephalus, within
the limits of the Order Primates. Inasmuch, however, as we are
dealing here principally with animals of the Class Mammalia, it
follows that the links with which we are concerned will be
comparable in point of importance with the two latter examples,
rather than with the first-mentioned instance.

In conclusion, the cases of such intermediate forms offer excellent
opportunities of employing and testing the principles ©f morpho-
logical examination upon which is based the system of classification
here set forth.

CHAPTER III.

THE MEMBERS OF THE MAMMALIAN ORDER PRIMATES.

In the foregoing chapter the relative positions of the various
Orders of the Class Mammalia were briefly reviewed from the
standpoint of evolution. If it be assumed that the typical or
representative mammal has during the period of its evolution
passed through vertebrate stages corresponding respectively to
those of the Fish, Amphibian, and Reptile, it seems intelligible
that in some mammals a greater number of ancestral characters
occur than in others. Such mammals as possess a greater
number of such reminiscent characters should be regarded as
primitive, while others should be described as less primitive, or
more highly evolved.

From this standpoint there is much evidence for assigning
the lowest place among the Mammalia to the Order Monotremata
composing the Sub-Class Prototheria. In series above these, and
consequently less primitive in their degree of evolution, are the
Metatheria, among which the Order Polyprotodontia are more
primitive than the Diprotodontia. Above the Metatheria1 come
the Eutheria, consisting as has been already remarked of some
nine Orders.

1 The fact must however not be overlooked, that while Prototheria and
Metatheria may thus be regarded as primitively and slightly evolved, there are
not lacking those who would regard some of their features as the result of extreme
specialisation and even degeneracy. For the brain, at least, the statements made
in the text appear to hold good (cf. Elliott Smith, “Origin of the Corpus Callosum,”
Linn. Trans, vii, Ser. 2), and to the braiu-evidence much weight must admittedly
be attached.

CHAP. Ill]

THE MAMMALIAN ORDER PRIMATES

With regard to the grouping of the several Orders of the
Section Eutheria, several difficulties present themselves. On the
whole, the Edentata and the Insectivora are the most primitive
of the Eutherian mammals : and it is remarkable that the
Insectivora are nearly approached by some members at least of
the Order Primates, to which, as will be presently shewn, the
study of Vertebrate Morphology assigns Man. But it seems to
be impossible to group the Eutherian Orders satisfactorily in an
evolutionary sequence, nor is it even possible to arrange sub-
classes or sections in such a linear series as shall be beyond the
reach of criticism : that this must be so will appear as a necessary
sequence of the arbitrary nature of the method of classification
adopted as has been already explained1. Nevertheless the general
relations of the various subdivisions may be represented graphic-
ally as was done by the late Sir William Flower in a diagram
published in his work on Osteology of the Mammalia (f. 1),
which may be supplemented by the diagram which follows
(Fig. 16).

It will no doubt be noticed that the expression “stage of”
such and such a generalised animal form is employed in this
diagram. It will therefore not be out of place to indicate that
on the hypothesis of evolution a given animal of the Mammalian
Class should shew, in its ancestral history, forerunners more closely
resembling reptiles, amphibia, or fishes. Even so, however, such
animals would possess the characteristics not of any particular reptile,
or amphibian, or fish known to modern zoologists, but rather the
characteristics of the generalised animals whence all the various
forms of reptiles, amphibia, or fishes respectively have sprung.
These considerations have the effect of rendering the construction
of an accurate diagram exceedingly difficult, and that now offered
is not to be regarded as expressing all the facts of the case, but as
the most convenient form of exposition available.

Some of the evidence for the assignation of the Monotremata
to a lowly position among Mammalia has been given in Note II.
and may now be recapitulated. It comprised the following
statements descriptive of the morphological anatomy of the
Monotremes.

1 v. supra, p. 25.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

Stage of Primate mammal (Order Primates).

Stage of Insectivorous mammal (Order Insectivora).

Stage of generalised Eutherian mammal (Section Eu-
theria).

Stage of generalised Metatherian mammal (Section
Metatheria).

Stage of generalised Therian mammal (Sub -Class
Theria).

Stage of generalised Prototherian mammal (Sub-Class
Prototheria).

Stage of generalised Mammal (Class Mammalia).

Stage of generalised Reptile (Class Reptilia).

Stage of generalised Amphibian (Class Amphibia).

Stage of generalised Fish (Class Pisces).
Fig. 1(3.

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES

(1) The possession of oviducts which are distinct from each
other throughout their course.

(2) The possession of a cloaca.

(3) The lack of vertebral epiphysial plates.

(4) The structure of the shoulder girdle (full development of
the several elements).

(5) The production of meroblastic ova,

as well as the physiological characteristic of being oviparous.

Turning now to the Metatheria (Marsupialia), the evidence for
the lowlier status of these as compared with the Eutherian
mammals depends chiefly on the conformation of the brain, which
lacks the great cerebral commissure known as the corpus cal-
losum ; herein the brains of Metatheria (Marsupialia) resemble
those of Monotremata and Reptilia, while differing from those
of Eutheria. The mode of nutrition of the embryo of Meta-
theria is considered by some to indicate the same primitive
position as compared with Eutheria, but this is a subject upon
which much more light must be shed before a final verdict can
be pronounced.

Within the range of the Eutherian Orders, the Insectivora
are unanimously regarded as meriting a most lowly position, in
any scheme of classification by which the more primitive and
the less highly evolved are compared. The evidence for this
conclusion may be summed up as follows :

(1) The number and characters of the teeth.

(2) The characters of the cerebral hemispheres.

(3) The mode of development of the amnion in the embryo.

(4) The arrangement of the somatic musculature.

It is perhaps not out of place to mention that a particular
insectivorous mammal, the so-called Gymnura rafflesii of the
East Indies, has retained in its anatomical structure the greatest
number of such characters as confer upon a mammal the dis-
tinction of occupying a low position in the scale, and for this
reason the Gymnura is regarded as the best living representative
of a generalised Eutherian mammal.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

Passing to the Order of the Primates, it will be necessary to set
forth in detail the general morphological characteristics of the
Order as well as those of its several subdivisions.

The Order Primates is subdivided into Sub-Orders, these
again into Families, and these successively into Genera and
Species in the following way (cf. Flower and Lydekker, Mammals).

/ Sub-Order
Lemuroidea 1

Order

PRIMATES <

Sub- Order
nAnthropoidea2

r Family Lemuridae (several genera and species).
Family Tarsiidae (a single species and genus).
Family Chciromyidae (a single species and
genus).

Family Ilapalidac (one genus, several species).
Family Cebidae (several genera and species).
Family Cercopithecidae „ „ „

" Family Simiidae „ „ „

(? Family Pitkecanthropidae) (lone genus and
' species).

Family Hominidae (one genus, and one or at
most two species).

It is to be noticed that the Family Pithecanthropidae is a
provisional one, the evidence for its existence in former times
resting on the morphological characters of a single calvaria, a
femur, and three teeth discovered by Eugene Dubois in a pliocene
deposit in Java. The recent work of Schwalbe (Strassburg)
on the fossil man of the Neanderthal near Diisseldorf (Germany)
seems to leave little room for escaping the conclusion that Homo
neanderthalensis is to be distinguished specifically from Homo
sapiens.

The ensuing notes on the characters of the Order, Sub-Orders
and Families of the Primates are abstracted (with permission)
from the work of Parker and Haswell on Zoology. References to
Gadow’s work on Classification will also be found.

1 Much diversity of opinion regarding the retention of this division into
Sub-Orders now exists (cf. Elliott Smith, Linn. Trans, vol. vm, part 10, page 417,
for recent literature and comments).

2 As an example of the diversity of modes of classification that given in the text
may be compared with that given by Cope ( Syllabus , Philadelphia, p. 120).

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES 33

I. Order Primates : Eutheria, nearly all of which are adapted
to an arboreal life, the limbs being prehensile owing to the pollex
and hallux being more or less completely opposable to the other
digits.

Dentition : heterodont ; diphyodont ; incisor teeth two in
number on each side above and below : the Aye-Aye (Cheiromys)
is the sole exception to this rule.

Digits: are, in nearly all, five in number, and are provided with
flat nails both in manus and pes : the pollex and hallux are
opposable.

Forearm: the ulna and radius are separate (i.e. not ankylosed
as in many Eutheria) and well developed.

Orbit : surrounded by a bony ring.

Clavicles : well developed.

Entepicondylar foramen : abnormal (Parker and Haswell say
absent).

Third trochanter of femur : abnormal (Parker and Haswell say
absent).

Stomach : simple in most instances.

Testes : descend into a scrotum.

Mammae : usually two in number, and thoracic in position.

Placenta : variable (diffuse or meta-discoidal).

Order. Taxeopoda.

Sub-Orders :

I. No clavicle (1) Condylarthra,

(2) Litopterna,

(3) Hyracoidea.

II. Clavicles present.

(a) Incisors growing from persistent pulps :

anapophyses present Daubentonioidea.

(b) Incisors with closed roots :

anapophyses present Quadrumana.

no anapophyses present Anthropomorpha.

Compare this with Herluf Winge’s Classification (in Archiv fur Anthropologic ,
1895), and note the comparative simplicity of criteria employed, when fossil forms
only are dealt with.

D. M.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

SUB-ORDER.

LEMUROIDEA.

i> f j c> t 5 Pm> § j m> § j
the incisor teeth are widely sepa-
rate in most eases.

Digits: of fore and hind limbs
bear flat nails except the second
digit of the hind limb, which bears
a claw. Both pollex and hallux are
opposable.

Orbit: surrounded by a bony
ring. (Cf. Fig. 18.)

Lacrymal foramen : external to
orbit.

Ape-like Primates, nocturnal in habit, and of comparatively low
organisation. (Cf. Fig. 17.)

Teeth: dental formula

tr.f.x-8.

Fig. 17. General external ap-
pearance of a Lemur.

"Par icTo - spV)e \ ^5O0fc

articulation ^°t)e

! ' i

Buclitor^ Uli'bplyrjoid I
bulla

Caninflonp

IrjdsrJcrm
. carjir^ toofV)

Fig. 18. Cranium, with mandible, of Lemur varius ; note the auditory bulla,
the articulation of parietal and alisphenoid bones, the facial extension of the lacry-
mal bone (cf. Fig. 12), the articulation of the frontal bone and maxilla behind the
lacrymal bone, the small forward projection of the orbital plate of the ethmoid
bone, the number of teeth, the small size of the upper and the great projection of
the lower incisor teeth. In the mandible, the canine-like tooth is a pre-molar by
position, and the canine tooth is incisiform.

CHAP. Ill]

THE MAMMALIAN ORDER PRIMATES

L"<cr

Colon : “ bent on a bight ” in its transverse portion. (Cf
Fig. 19.)

Cerebral hemispheres:
feebly convoluted and not
prolonged far backwards
overcerebellum (Fig. 20):
rhinencephalon relatively
well-developed.

Mammae: two in num-
ber, thoracic in position:
they may be supplement-
ed by an abdominal pair.

Uterus : bi-cornuate.

Placenta : diffuse.

Hyoid bone: anterior
larger than posterior
cornu.

The Sub-Order Lemu-
roidea comprises the true
Lemurs (Family Lemu-
ridae), so called from their
ghost-like appearance at
night. Geographically,
their distribution is al-
most entirely confined to
the island of Madagascar,
in which they have found

congenial surroundings ; and of that local fauna they are very
characteristic. A few examples occur in Africa and Asia. Fossil
representatives occur, not in Madagascar only, but also in Europe
and in North America.

Besides the Lemuridae, two other animals are placed in this
Sub-Order. These are (a) the Tarsius spectrum, an Asiatic animal,
and ( b ) the Aye- Aye, Cheiromys, or Daubentonia madagascariensis,
an inhabitant, as its name indicates, of Madagascar. These two
animals are so peculiar that each is assigned to a separate family
of which it constitutes the sole living genus and species. Tarsius
spectrum differs from all other Lemuroidea (while it agrees with

3—2

Fig. 19. Part of the alimentary canal of a
Lemur: note the curiously contorted colon, and
the enormous appendix caeci.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

the Anthropoidea), in the possession of a discoid placenta. Its
nearest ally is a fossil form occurring in North Amei’ica. (Anapto-
morphus. Cf. Chap, xvi.)

The Aye-Aye has no known fossil representative or near rela-
tion. It was thought at first to be a sort of arboreal rodent, for its
incisor teeth are so modified as to reproduce the rodent type.
When however the general morphology of the Aye-Aye became
known, the summary of evidence did not support the indication
afforded by its incisor teeth, but assigned to it the place in the
classification which it now occupies.

SULCUS RECTUS

FISSURE OF 9YLVIUS

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES

Fig. 20. Six views of the right cerebral hemisphere of a Lemur : the first view
is the frontal or anterior aspect ; then follow in turn the vertical, lateral, mesial,
basal and occipital aspects : note the large size of the olfactory nerve, and the
paucity of cerebral convolutions in comparison with the human cerebrum.

SUB-ORDER.

ANTHROPOIDEA.

Most highly organised Primates, chiefly modified for and adapted
to an arboreal mode of life.

Teeth : the median incisor teeth are in contact with one another.

Digits : these are provided with fiat nails (except in the Hapa-
lidae).

Pollex : in a few instances is rudimentary or absent, in most it
is well developed.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

Orbit : the post-orbital boundary is a bony wall extending
inwards from the post-orbital ring, and separating the orbit from
the temporal fossa. (Cf. Fig. 21.)

Fig. 21. Cranium, with mandible, of Cebus capucinus (Cebidae). Note the
auditory bulla, and shallow auditory passage ; the spheno-parietal and lacrymo-
ethmoidal articulations, the latter suture being marked by a small circle ; three
molar teeth are seen in each jaw.

Fig. 22. Part of the alimentary canal of a Cercopithecus monkey (Cercopithe-
cidae) : note the lack of contortion in the colon, and the absence of an appendix
caeci.

Lacrymal foramen : this is situated within the orbital margin.

Colon : not looped as in Lemuroidea. (Cf. Fig. 22 with Fig. 19.)

Brain: cerebral hemispheres much convoluted and prolonged
backwards to cover the cerebellum to a considerable extent (Figs.
23, 24, 25 and 34) : rhinencephalon much reduced.

Mammae : two in number and thoracic in position.

Uterus : this has no cornua properly so called : Fallopian tubes
spring directly from the body of the uterus.

Placenta : this is deciduate and meta-discoidal.

Hyoid bone : the posterior cornu exceeds the anterior cornu in
size.

CHAP. Ill]

THE MAMMALIAN ORDER PRIMATES

CENTRAL SULCUS

Fig. 23. The left cerebral hemisphere of an American (Platyrrhine) ape, Ateles
variegatus : the lateral and mesial aspects of the hemisphere are shewn.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

CENTRAL SULCUS

INTRAPARI ETAL SULCUS

COMPENSATORY SULCUS

HIPPOCAMPAL FISSURE

Fig. 24. The left cerebral hemisphere of a Nasalis monkey (Cercopithecidae) :
the lateral and mesial aspects are shewn. (Hose Donation n. Mus. Anat. Cant.)

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES

CENTRAL SULCUS

1 INTRAPARIETAL SULCUS

CALLOSO- MARGINAL SULCUS

COMPENSATORY SULCUS

OR RHINAL FISSURE

HIPPOCAMPAL FISSURE

Fig. 25. The cerebral hemispheres of a Gibbon (Simiidae) : the lateral and
mesial aspects are shewn. (Hose Donation ii. Mus. Anat. Cant.)

THE MAMMALIAN ORDER PRIMATES

[sect, a

Family I. Hapalidae1.

Dental formula : i, § ; c, { ; pm, § ; m, § = 32.

Pollex : not opposable.

Digits: bear claws, no nails : the hallux is an exception to this
rule.

Cheek pouches : not developed.

Ischial callosities : not developed.

External auditory meatus : not prolonged into an osseous tube.
(Of. Fig. 26.)

Spl[)e r)o- (parietal

articu latior)

Fig. 26. Cranium, with mandible, of Hapale jacchus (Hapalidae). Note the
auditory bulla, the spheno-parietal articulation and in the orbit the lacrymo-
ethmoidal articulation ; two molar teeth are seen in each jaw, and the incisor
teeth project strongly.

Tail : non-prehensile.

Nasal septum : wide (Platyrrhine).

The foregoing family includes the Marmosets.

Family II. Cebidae 2.

Dental formula : i, § ; c, -f ; pm, f ; m, § = 36.

1 (Hapale: from a Greek word indicative either of minute size, or docile
temperament.)

2 (Cebus : the Arabic woi’d for ape.)

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES

Pollex : not opposable, in some instances rudimentary or absent.

Digits : all have flat nails.

Cheek pouches : not developed.

Ischial callosities : not developed.

External auditory meatus as in Hapalidae (cf. Figs. 21 and 26).

Tail : sometimes prehensile.

Nasal septum broad (Platyrrhine).

This family includes among others the Howling Monkey
(Mycetes), Squirrel Monkey (Chrysothrix), Spider Monkey (Ateles),
and Capuchin Monkey (Cebus).

It should be particularly noted that members of the two pre-
ceding families (Hapalidae and Cebidae) agree in the possession
of a wide septum and space between the nostrils. They are for
this reason called Platyrrhine Monkeys. Besides this character-
istic, other morphological features distinguish the Platyrrhine
apes from the other Anthropoidea, which from the possession of
a narrow intra-narial space and consequent downwardly directed
nases are called Catarrhine. In Craniology the terms Platyrrhine
and Catarrhine are also used, but in this study they refer to the
proportions of the apertura pyriformis nasi of the skull, and not to
the intra-narial space of the face.

Family III. Cercopithecidae1. (Cf. Fig. 27.)

Dental formula : i, § ; c, { ; pm, § ; m, § = 32.

Pollex : opposable, in the genus Colobus not developed at all.
Cheek pouches : developed in many cases.

Ischial callosities : developed to a high degree.

External auditory meatus : guarded by an osseous tube formed
by the tympanic bone. (Cf. Fig. 28.)

Tail : non-prehensile.

Nasal septum: narrow, the nostrils close together in consequence.
Sternum : narrow and rod-like.

Caecum : has no vermiform appendix.

This family comprises the Baboons (Papio or Cynocephalus),
the Macaques (Macacus), the Cercopitheci, Semnopitheci, &c.

1 (Cercopithecus : a tailed ape.)

THE MAMMALIAN ORDER PRIMATES

[SECT. A

Fig. 27. An adult male Nasalis or Proboscis monkey; a variety of Sernno-
pithecus (Cercopithecidae) from Borneo. (Hose Donation, No. ir. Mus. Anat.
Cant.)

Pronto * S^jUC*VT}OU&
I orlicuicatlor)

Fig. 28. Cranium, with mandible, of a Macacus monkey (Cercopithecidae) ; note
the absence of an auditory bulla ; the substitution of fronto-squamous and fronto-
maxillary for spheno-parietal and lacrymo-ethmoidal articulations : note also the
number of teeth, and compare with Figs. 21 and 26.

Fig. 29. Fig. 30. Fig. 31.

Fig. 29. Adult male Gorilla (Simiidae) ; the hair has been lost owing to
inadequate preservation in alcohol. (Holt Donation, Mus. Anat. Cant.)

Figs. 30 and 31. Other views of the same specimen.

Dental formula : as in the preceding family, viz. :
i, ; c, | ; pm, \ ; m, § = 32.

Pollex : opposable.

Ischial callosities : found in one genus only, viz. Hylobates,
the Gibbons.

External auditory meatus: an osseous tube, as in Family III.
(Cf. Figs. 32, 33.)

Tail : not developed externally.

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES

Family IV. Simiidae1. (Cf. Figs. 29, 30, 31.)

1 (Simia : exact meaning doubtful ; either “flat-nosed” or “mimic.”)

THE MAMMALIAN ORDER PRIMATES

[SECT. A

Fig. 32. Cranium, with mandible, of a young Gorilla (Simiidae) ; the first tooth
of the permanent set has appeared (permanent molar tooth). Note, in contrast to
Fig. 83, the comparatively large brain-case. There is no auditory bulla : the
auditory passage is long, but not so long as in adults : there are fronto-squamous
and fronto-max illary articulations. Osseous ridges and crests are still undeveloped.

f Fig. 33. Cranium, with mandible, of an adult Gorilla (Simiidae) : note the absence
of an auditory bulla, the presence of great bony crests ; and of lronto-squamous
and f r on to -m axillary articulations (the latter within the orbit in place of a lacrymo-
ethmoidal junction). The canine teeth are enormously developed in the male sex.

CHAP. Ill]

THE MAMMALIAN ORDER PRIMATES

Nasal septum : as in Family III.

Sternum : flat (lati-sternal type).

Caecum : vermiform appendix present.

Os centrale carpi : sometimes united with the os radiale carpi
to form the scaphoid bone.

Fig. 34. Lateral aspect of the right cerebral hemisphere of a young Gorilla
(Simiidae). The olfactory nerves are attenuated in point of size: the cerebral
surface is much more convoluted than in the preceding examples and recalls the
appearance of the human cerebrum. Cf. with Figs. 20, 23, 24, 25, and p. 38.

This family includes the Gibbons (Hylobates), Orang-utans
(Simia), Chimpanzees and Gorillas (Anthropopithecus niger and
gorilla).

The main characters conform so exactly to those of the
preceding family that recapitulation is unnecessary. The Homi-
nidae are however distinguished from the Simiidae by several
morphological characteristics of which the following are the most
important.

SudcuS

/ 1
/ l

Family V. Hominidae.

THE MAMMALIAN ORDER PRIMATES

[SECT. A

Hallux not opposable.

Pelvic limbs much longer and bulkier than the pectoral.

Cerebral hemispheres enormously developed in bulk and in
the complexity of the convolutions.

Many morphological modifications have been induced by the
assumption of the erect attitude.

This family includes members of the two Human species.

It is a matter for discussion whether there should be inter-
polated between the Families Simiidae and Hominidae another,
viz. Pithecanthropidae. Till further remains of Pithecanthropidae
have come to light this question must remain in abeyance. Some
authors would rank Pithecanthropus erectus with the Simiidae,
and others again associate this form with the Hominidae.

In concluding the account of the Order Primates, a few words
may be added as to the method pursued in assigning to Man a
place among the Mammals. It will have already been noticed
that in the account given of the Order Primates, several morpho-
logical characters were enumerated. Should a mammal be
presented for examination with a view to assigning it to its
appropriate order, it would be necessary that the mammal should
satisfy the conditions just referred to, before such assignation could
be made in respect of the Order Primates. But the exact number
of conditions is a matter upon which no final decision has been
arrived at, and in practice it is found necessary for convenience
in classifying animals to limit the number. An example of the
procedure may facilitate this explanation. We may for instance
consider the morphology of a typical Primate mammal and
enumerate a dozen chai’acters in which it presents the requisite
conformation. If then we should make a corresponding list for
the human body, we should find that the same conditions were
satisfied in this as in the preceding case. Finally taking such
a form of mammal as Galeopithecus volans (which was included
among the Primates at an epoch when the single character of the
possession of two incisor teeth in each jaw was regarded as the
sole qualifying condition), we should see reason for regarding it as
outside the limits of that Order.

The comparison may be drawn up as follows :

CHAP. Ill] THE MAMMALIAN ORDER PRIMATES

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THE MAMMALIAN ORDER PRIMATES

[SECT. A

Upon such evidence as is provided by the foregoing table,
systeniatists have decided that Man is to be included within the
Order Primates, while Galeopithecus is excluded from that Order
and relegated to the Order Insectivora.

We have thus given a general idea of the position of the Homini-
dae within the Order Primates. In order to strengthen the argument
for assigning to Man this position, a more detailed exposition of the
anatomical characters of the Primates seems advisable. For this
reason we have selected as typical examples of the Order one of
the Lemurs, one of the Cercopithecidae, and one of the Simiidae.
The anatomy of each of these will now (Chapter IV.) be briefly
reviewed, and arranged in a manner suitable for comparison with
descriptive human anatomy, which is here excluded for lack of
space. To these descriptions will then be added (Chapter V.)
detailed accounts of the skulls of the most nearly related family
to the Hominidae, viz. the Simiidae. The dentition of the same
families will also be described separately (Chapter VI.).

CHAPTER IV.

ON THE GENERAL ANATOMY OF THE PRIMATES.

In the chapter dealing with the subdivisions of the Order
Primates, the characters which have proved of taxonomic value
in distinguishing the Sub-Order Lemuroidea were enumerated.
The present note aims at giving a few additional facts descrip-
tive of the anatomy of such a representative of the Sub-Order
as the Lemur, taking for example Lemur mongoz, an animal
about the size of a cat.

The Skeleton. The skull (Fig. 35) is elongated, the brain-
case being somewhat flattened, and the facial bones project as

Fig. 35. Cranium, with mandible, of Lemur varius ; note the auditory bulla,
the articulation of parietal and alisphenoid bones, the facial extension of the lacry-
mal bone (cf. Fig. 12), the articulation of the frontal bone and maxilla behind the
lacrymal bone, the small forward projection of the orbital plate of the ethmoid
bone, the number of teeth, the small size of the upper and the great projection of
the lower incisor teeth. In the mandible, the canine-like tooth is a pre-molar by
position, and the canine tooth is incisiform.

THE LEMUROIDEA.

■pancto'S

arliculat

4—2

THE GENEKAL ANATOMY OF THE LEMUROIDEA [SECT. A

a snout, at the extremity of which is the aperture of the nose.
The orbit is separated incompletely from the temporal fossa by
a post-orbital bar. On the inner orbital wall, the frontal and
maxillary bones join along a suture which may be 5 mm. long,
and thus widely separate the os planum of the ethmoid from the
lacrymal bone. The nasal duct opens on the facial surface and
not within the orbit. The infra-orbital canal runs along the
orbital floor as a groove, and is not covered in above.

In the temporal fossa, the alisphenoid joins the parietal bone,
and thus the frontal and the temporal bones are separated.

On the inferior aspect of the skull, the palate is seen to be
elongated ; the glenoid fossa is so shallow as hardly to merit
that description : there is a well-developed post-glenoid tubercle,
immediately behind which a large foramen, for the primitive
jugular vein, leads to the endocranial cavity. The tympanic bone
is expanded into a bulla and the external auditory meatus is very
short. The sutures between the pre- and post-sphenoid, and
between the latter and the basi-occipital, as well as the metopic
suture, persist in adult life.

The median incisor teeth are separated by a wide interval, and
are two in number in each jaw on each side of the skull. On each
side (above and below) is one canine tooth. The lower canine is
so modified as to resemble an incisor, and the first lower jjremolar
resembles a canine tooth. The position of the latter with regard
to the upper canine tooth shews however that it is really a
premolar, for it is posterior to the upper canine, whereas the true
lower canine always comes in front of the upper tooth of that
name when the jaw is closed. (This view is not universally adopted
however: see Forsyth Major, Geological Magazine, 1900.) There
are three premolar and three molar teeth ; the latter bear usually
three cusps (though two subsidiary cusps are often developed from
the cingulum), and are consequently described as of tri-tubercular
type. (For fuller details, cf. Chapter VI.)

Vertebral Column. The vertebrae usually number fifty-six,
viz. cervical 7, thoracic 12, lumbar 7, sacral 3, caudal 27. The
spinous process of the second cervical vertebra is very large
and quite overshadows the other cervical spines. The lumbar
vertebrae have well-developed anapophyses which are directed

CHAP. IVJ THE GENERAL ANATOMY OF THE LEMUROIDEA 53

downwards and embrace the roots of the anterior zygapophyses
of the succeeding vertebra. This arrangement is also found in
the Cercopithecidae. As regards the curvature of the vertebral
column, it is very slightly convex downwards in the cervical
region. Then follows a thoraco-lumbar curve with downwardly
directed concavity.

The scapula is elongated in the direction of the axis of its
spine. The coracoid process is sharp and tapering and is closely
applied to the head of the humerus.

The humerus has a straight shaft : the outer lip of the bicipital
groove is prominent and the inner lip undeveloped. At the lower
end of the bone the internal epicondyle is seen to be large and
tuberous. The olecranon fossa is subdivided into two lateral halves
by an osseous ridge which occurs occasionally in the higher Primates,
including Man.

In the carpus, the os centrale is distinct. The pollex is dimi-
nutive, owing to the shortness of its metacarpal bone and terminal
phalanx : the first phalanx equals the metacarpal in length. All
the terminal phalanges are very short.

The ossa innominata are elongated antero-posteriorly, i.e. in the
opposite direction to that in which their characteristic width is
shewn in Man. The iliac bones are long and narrow : the pelvic
brim (true pelvis) is nearly circular, thus contrasting with many
lower mammalian forms and approximating to the human type.
The symphysis barely extends beyond the pubic bones, and the
tubera ischii are smaller and less everted than in the lower
Anthropoidea.

The femur has a slender rectilinear shaft1, a small globular
head, and a short stout neck ; a third trochanter may occur. At
its lower end, the bone appears as though transversely compressed,
when compared with the human femur. The patella is also
narrow. There is a sesamoid bone in the outer head of the
gastrocnemius muscle, which often remains attached to the femur.
The tarsus is flat, and the heel (os calcis) is prominent ; the

1 In the giant extinct Lemurs known as Megaladapis madagascariensis and
M. insignia, there is a curious flattening of the shaft, seen in both the humerus
and femur, as though pressure had been applied in the sagittal direction. The
specimens in the collections at S. Kensington and Vienna present these characters.

54 THE GENERAL ANATOMY OF THE LEMUROIDEA [SECT. A

hallux is long, and distinctly stouter than the other digits. The
terminal phalanges of all the digits are very small in comparison
with those situated more proximally : the terminal phalanx of the
second digit is tapering and spine-like, and thus corresponds to
the peculiar shape of nail which it bears.

Muscular System1. Panniculus system : the dorso-humeralis
sheet is well developed. Below the mandible, the cutaneous mus-
culature is divisible into a superficial (platysma) stratum, and a
deeper sheet corresponding to the M. sphincter colli (cf. Ruge,
quoted by Wiedersheim : Structure of Man, p. 106), Fig. 36.

Fig. 36. Cutaneous musculature of the head of Lemur mongoz to shew some
of the more definite constituents of the muscular sheet.

The M. latissimus dorsi does not blend with the M. teres
major: there is a well-developed dorsi-epitrochlear muscle. In
the lower limb, the M. biceps femoris arises from the tuber ischii,
and is inserted not into the fibula, but into the fascia of the
leg, some of its fibres running into the outer part of the fascia
of the leg and being thus traceable down to the external malleolus.

1 Lucae’s account for Lemur macaco has been mainly followed, though checked
in many instances by the author’s dissections. Cf. Statik und Mechanik der Quad-
rupen, 1883. (Camb. Univ. Lib. MB. 43. 14.)

CHAP. IV] THE GENERAL ANATOMY OF THE LEMUROIDEA 55

The M. gluteus maximus (arising from caudal vertebrae in
addition to other points of origin) is largely inserted into the
posterior surface of the femur.

The adductor mass of muscles is divisible into three parts.

The M. psoas minor is present.

The M. soleus is attached to the fibula.

The M. plantaris is traceable into the plantar fascia.

The M. flexor accessorius is absent.

The M. interossei are grouped around the median digit.

Most of the muscles of the shoulder-girdle closely resemble
those of Man.

SULCUS REOTUS

FISSURE OF SYLVIUS

THE GENERAL ANATOMY OF THE LEMUROIDEA

CALLOSO- MARGINAL
SULCUS

'parallel sulcus

ORBITAL SULCUS

SULCUS * X ”
FISSURE OF SYLVIUS

Fig. 37. Six views of the right cerebral hemisphere of a Lemur : the first view
is the frontal or anterior aspect ; then follow in turn the vertical, lateral, mesial,
basal and occipital aspects : note the large size of the olfactory nerve, and the
paucity of cerebral convolutions in comparison with the human cerebrum.

The M. coraco-brachialis is inserted along the greater part of
the shaft of the humerus.

The M. teres major has also an extended tendinous insertion.

The M. flexor pollicis longus is not a separate muscle.

Vascular System. The Heart. The right auricle is nearly
twice as large as the left. The conus arteriosus is well marked,
forming a distinct bulging at the root of the pulmonary artery.

The precaval vein, like the great arterial trunks arising from
the aortic arch, is of considerable length.

CHAP. IV] THE GENERAL ANATOMY OF THE LEMUROIDEA 57

The occurrence of a rete mirabile (arterial) in the limb-vessels
of Nycticebus tardigradus is very remarkable.

Nervous System. The Brain. Fig. 37.

The rhinencephalon is distinct, the olfactory tracts being well
developed, and the rhinal fissure is visible on the lateral cerebral
surface, owing to the lack of development of the neo-pallium1 2.

The marginal pallium is bounded by a hippocampal fissure,
and the uncus, hippocampus major, its posterior continuation
the gyrus A. Ketzii, the fimbria and the fornix are all
present and distinct. The neo-pallium is (comparatively) feebly
convoluted, but the following sulci are distinct (a) on the lateral
convexity ; the Sylvian fissure (“ posterior limb ” of Human Ana-
tomy), the intra-parietal, parallel, orbital, straight and central
sulci : ( b ) on the mesial aspect ; the calloso-marginal and calcarine
sulci, and that component of the internal parieto-occipital sulcus
of the higher Anthropoidea which is described as the para-
calcarine sulcus. (Cf. Elliott Smith, Linn; Trans, vm. Part 10:
The Brain in the Lemur oidea, for full descriptions and references.)

Thoracic and Abdominal Organs'. The viscera occupy a
lower level in comparison with the vertebral column, than is the
case in the highest Primates. The Lemurs thus differ from the
anthropoid apes, in which the condition more nearly resembles
that found in Man.

The Lungs. The median surfaces of the lungs shew very
distinct impressed areas for neighbouring structures. The aortic
groove is deeper than in Man. The trachea and oesophagus
occupy distinct grooves, the trachea impressing the right lung,
the oesophagus grooving the left lung.

The spleen is an elongated crescent-shaped organ tucked
round the outer convex border of the left kidney. This form of
spleen much more nearly resembles that of quadrupeds than that
of the higher apes.

As regards the vertebral column, the left kidney is situated
posteriorly to the right. Both are of small size. The duodenum

1 For the terminology here employed, reference should be made to Chapter xv.

2 Cf. I)r Patten’s description, Proc. Anat. Soc. 1900.

58 THE GENERAL ANATOMY OF THE LEMUROIDEA [SECT. A

is of considerable length and L-shaped, consisting of a longer
vertical part and a shorter transverse part. The latter crosses the
vertebral column at the level of the 4th lumbar vertebra.

The transverse colon (Fig. 38) is looped in a very character-
istic manner (see note on characteristics of Lemuroidea in general).

Pelvic Organs. The seminal vesicles in the male are very
large : each consists of a
convoluted tube occupy-
ing about three turns of
a spiral.

The bladder resem-
bles that of the human
foetus both in position
and form. In both male
and female the rectal
pouch is very evident.

In the female, the
Fallopian tubes are short
and coiled : the uterus is
bicornuate; the clitoris
of considerable size1.

Of the preceding
characters, the following
are of interest as throw-
ing light on certain
human conformations or
anomalies explained by

reference to the morpho-
lopry of lower forms. (Of. Lemur i note the curiously contoited colon, and

v the enormous appendix caeci.

Chap. IX.)

1. Extensive lacrymal bone.

2. Post-glenoid foramen.

3. Tri-tubercular molar teeth.

4. Imperfect post-orbital wall.

5. Entepicondylar foramen humeri.

1 Dr Patten, Proc. Anat. Soc. 1900.

CHAP. IV ] THE GENERAL ANATOMY OF THE ANTHROPOIDEA 59

6. Two-folcl stratum of cutaneous muscles.

7. M. dorsi-epitrochlearis.

8. Extent of M. coraco-brachialis.

9. Comparative paucity of cerebral convolutions.

10. Distinctness of rhinal fissure.

11. Form of bladder.

12. Bicornuate character of uterus.

ANTHROPOIDEA.

As representatives of this Sub-Order there will now be con-
sidered examples of the Families Cercopithecidae and Simiidae.
As a representative of the Family Cercopithecidae, a member of
the Genus Cercopithecus has been selected.

The Skeleton. The skull (Fig. 39) is distinguished by the
relatively large proportions of the facial part : in males (especially

Fig. 39. Cranium, with mandible, of a Macaeus monkey (Cercopithecidae) ; note
the absence of an auditory bulla ; the substitution of fronto-squamous and fronto-
maxillary for spheno-parietal and lacrymo-ethmoidal articulations : note also the
number of teeth, and compare with Figs. 21 and 26.

aged animals) the temporal ridges are often prominent, and there
may be prominent supra-orbital ridges. The snout-like projection
of the facial bones is pronounced in the Dog-faced monkeys, but is

60 THE GENERAL ANATOMY OF THE CERCOPITHECIDAE [SECT. A

much diminished in the Cercopitheci. A wall bounds the orbit
posteriorly, and the nasal duct opens within the margin of that
cavity. On the inner orbital wall, the lacrymal bone is separated as
in the Lemuridae, from the os planum of the ethmoid, by the inter-
position of the frontal and maxillary bones which unite along a
fronto-maxillary suture which often measures 10 mm. in length.
The infra-orbital canal is not roofed over. In the temporal fossa,
the alisphenoid is separated from the parietal by the interposition
of the frontal and squamous portion of the temporal bone, which
unite along a fronto-squamous suture. The New- World Apes
commonly present the lemuroid feature of a parieto-sphenoid
articulation. The malar bone in these apes may also be prolonged
backwards so as to touch the parietal bone.

The palate is elongated, the glenoid fossa deeper than in the
Lemurs ; the post-glenoid tubercle is well developed and spiny.
The tympanic bone is expanded to form a tube which protects
the external auditory meatus and tympanic membrane, and there
is no auditory bulla in the Old-World monkeys, though this feature
characterises their New-World representatives. The anterior and
inferior part of the petrous portion of the temporal bone is
commonly inflated in appearance. The basi-occipito-sphenoidal
suture persists for some considerable time after the completion of
the dentition.

The dental formula is identical with that of Man (the New-
World monkeys having an additional premolar tooth in each jaw) ;
the molars commonly bear four distinct cusps arranged in two
pairs, an anterior and a posterior. (For fuller details, v.
Chapter vi.)

Vertebral Column. The cervical vertebrae are seven in number,
the thoracic and lumbar together are nineteen, of which twelve or
thirteen usually bear ribs, and are thus to be regarded as the true
thoracic elements. Three sacral vertebrae and a very variable
number (3 — 26) of caudal vertebrae complete the series. In the
lumbar region, spine-like anapophysial processes (Fig. 40) are
directed backwards from each vertebra to embrace the anterior
zygapophyses of the succeeding one. The curvature of the vertebral
column is much simpler than in Man, being a simple thoraco-lumbar

CHAP. IV] THE GENERAL ANATOMY OF THE CERCOPITHECIDAE 61

curve whose concavity is directed downwards. Anterior to this is
a cervical curvature in the opposite
direction. Posteriorly, owing to a
tilting upwards of the sacrum, an
appearance of convexity downwards
is often seen especially in the Baboons
(Cynocephali) (Fig. 41).

The scapula is very broad (Fig.

42) (when measured in the general
direction of the spine) in comparison
with its diameter from the superior to
the inferior angle : its “index” is 118
approximately. In Man, the index
is about 65. The acromion process
is comparatively small. The scapula
in general resembles those of ani-
mals with quadrupedal gait rather
than such as have even partially
assumed the erect attitude (as the
Simiidae).

The outer lip of the bicipital groove in the humerus is very
prominent, the inner lip being feebly developed or absent. At
the lower end of the bone, the articular surface is not so sharply
differentiated into capitellum and trochlea as in the case of Man :
the conformation of the capitellum, in particular, suggests that
flexion and extension (the characteristic movements of this joint
in animals with quadrupedal structure) have not been far en-
croached upon by pronation and supination. The angle of torsion
of the humerus amounts on the average to about 100° (cf. Broca’s
figures: Carnivora, average angle 95°; Europeans, 161°). The
carpus retains a distinct os centrale : the pollex is very short,
owing chiefly to the diminutive size of the phalanges.

The pelvis is transversely narrow (like the “ thoracic cage ”),
the ossa innominata being elongated antero-posteriorly, i.e. as
measured from the crest of the ilium to the tuber ischii ; they
thus are strongly contrasted with the corresponding bones in Man.
The pubic symphysis is long, and indeed so extensive that the
ischial bones come into contact, so that the symphysis is really
pubo-ischiatic. The tuber ischii is large and everted.

Rqapopfypest;

Fig. 40. Lumbar portion of the
vertebral column of a Cercopitkecus
monkey (Cereopithecidae), to shew
the anapophyses projecting late-
rally from the vertebral pedicles.

62 THE GENERAL ANATOMY OF THE CERCOPITHECIDAE [SECT. A

The femoral head is small, and the neck short in comparison
with the human femur. There is a very distinct linea spiralis
in some cases, but the linea aspera is only feebly developed.
Inferior ly, the lack of transverse width is characteristic, while the

Urjerupted

.lOOlf)

PaQcreas

Lurpl/ar
Curvature
Recturr)
J3ladder

Fig. 41.

Fig. 41. Mesial section of the (frozen) body of a Cynocephalus monkey (Cerco-
pithecidae). Note the enormous size of the jaws, and the comparatively small
thoracic capacity and extent, and the vertebral column is much less sinuous than
in Man, but the anterior lumbar convexity is incipient and distinct.

Fig. 42. Scapulae, (a) of a Cercopithecus monkey, (b) of Man.

curvature of the condyles is much more semicircular, when regarded
from the side, than in the case of Man. The patella is narrow and

CHAP. IV] THE GENERAL ANATOMY OF THE CERCOPITHECIDAE 63

plays equally on each condyle. Commonly a sesamoid bone is
found in the outer head of the gastrocnemius muscle.

The tarsus is flattened, and its constituents similar in number
to those of the human tarsus : the hallux is very short when
compared with the other digits : this is chiefly due, as in the
manus, to the shortness of the phalanges.

Muscular System. The panniculus sheet is represented in
the axillary region by a distinct dorso-humeral muscle. The
humeral insertion of the M. latissimus dorsi is in close proximity
to the tendon of the M. teres major, by which tendon it may
occasionally be pierced (Kohlbriigge1). From the tendon of the
M. latissimus dorsi, descending to the elbow, is the M. dorsi-
epitrochlearis (or latissimo-condyloideus muscle) which is so con-
stant among apes.

The M. biceps femoris possesses but a single head (the “ long ”
head of human anatomy), which is inserted and lost in the fascia
covering the muscles on the anterior aspect of the leg, and through
the intervention of this fascia becomes attached to the tibia. In
the American monkeys the short or femoral head of this muscle
is found, as described by Windle and Parsons ( Proc . Anat.
Soc., 1900).

The M. gluteus maximus arises from the caudal as well as
the sacral vertebrae, the caudal part forming a separate caudo-
femoralis muscle ; the femoral insertion of the M. gluteus maximus
is very small. The small separable portion of the M. gluteus
minimus known as M. scansorius is not usually present.

The adductor mass of femoi’al muscles is much subdivided.
Of the M. adductor magnus it is characteristic that the portion
of the muscle supplied by the sciatic nei’ve is distinct from that
part which receives its innervation from the obturator nerve.
The insertion encroaches on the popliteal area. The M. psoas
minor is usually present but is only feebly developed, as in the
majority of the Primates. The M. soleus is characterized by the
possession of a fibular origin only, the tibial origin not having
been superadded in the Cercopithecidae. The M. plantaris tendon
is inserted into the plantar fascia.

1 Muskeln und Nerven der Primaten, Amsterdam, p. 69.

THE GENERAL ANATOMY OF THE CERCOPITHECIDAE [SECT. A

Nj.abd.n3

M.alrd.

The M. flexor accessorius (Quadratus plantae) is variable : in a
Cercopithecus monkey it was found to possess two heads of origin
(Fig. 43), though in Cynocephalus mormon
but one head is found. The pedal inter-
ossei muscles are not divisible into plantar
and dorsal groups as in Man, but occupy
the same plane and are grouped about an
axis passing through the third median
metatarsal bone and digit. There is a
considerable complexity and interweaving
of the long flexor tendons of the digits.

With regard to muscles of the upper
limb, the duplicity of the coraco-brachialis
mass of muscle is to be remarked, the two
components being distinguished as the
coraco-brachialis longus and the coraco-
brachialis brevis. The tendon of M. teres
major occasionally pierces that of the
M. latissimus dorsi: the deep and super-
ficial flexors of the digits are fused to some
extent at their origins, and a deep flexor tendon for the pollex
springs from the tendon of the flexor profundus digitorum before
the latter subdivides (Fig. 44). These flexor
tendons are curiously interlaced near their
insertions. There is a complete double set of
extensor tendons for the digits, while to the
pollex run extensors corresponding to the M.
extensor ossis metacarpi and the M. extensor
major of the human pollex, the M. extensor
minor pollicis being absent. To the other
digits the M. extensor communis supplies
four superficial tendons, while the M. exten-
sor indicis supplies deep tendons to digits II
and III, and the M. extensor “ minimi digiti ”
corresponding tendons to digits IV and V.

In addition to the foregoing brief re-
view, the constant occurrence in the Cerco-
pithecidae of a number of muscles regarded

IcPidoi} to

hi**

Fig. 43. Deep dissection
of the plantar muscles of
a Cercopithecus monkey
(Cercopithecidae) to shew
the origins of the M. flexor
accessorius digitorum (M.
quadratus plantae), and of
the M. flexor longus lml-
lucis. (From a dissection
by Mr R. Crawford.)

Fig. 44. Deep flexor
tendons of the manus
of a Cercopithecus mon-
key (Cercopithecidae) to
shew the origins of the
flexor longus pollicis,
and of the lumbrical
muscles. (From a dis-
section by Mr Graham-
Smith. )

CHAP. IV] THE GENERAL ANATOMY OF THE CERCOPITHECIDAE 65

as anomalous in human anatomy is a striking feature. Among
these the following may be mentioned as being the most commonly
recognised, viz. : the M. omo-cervicalis (acromiotrachelian) the
M. dorsi -humeralis already mentioned, the M. occipito-scapularis
(Fig. 45). Moreover several muscular masses to which in human

- occip. scap.

_ tvp si rryafet.

. NJ. lev. ai^. £>cap.

-Scapula
_ occip. s>ca j>.

. ‘ocrr. rr)acj.

(Vj.lat. dor&i

Fig. 45. Dissection of the nuchal and cervical muscles of a young Baboon
(Cynocephalus ; Cercopithecidae). The occipito-scapular muscle, a simian charac-
teristic, is shewn.

anatomy a single name is applied, will be found to consist in
the Cercopithecidae of two or more constituent elements. Ex-
amples of such muscles are the double M. coraco-brachialis already
described and the M. gracilis.

D. M.

66 THE GENERAL ANATOMY OF THE CERCOPITHECID A E [SECT. A

Central Nervous System : the Brain. The cerebral hemi-
spheres are, in comparison with the cerebellum, larger than in the
Lemuroidea and their surfaces are more convoluted, the principle
sulci of the human brain being here recognisable, though modified
much in form. This preponderance in size of the hemispheres
dwarfs the quadrigeminal and geniculate bodies. The pons varolii
is broad, but not so broad as to overlap the trapezium which is
quite easily seen. The pyramidal tracts and olives are distinct.
With regard to the first cranial nerve, it is to be noticed that the
bulbous extremity is attached to the base of the brain by a long
slender nerve. There is a distinct tuberculum olfactorium, and the
post-rhinal fissure persists in the incisura temporalis. The relative
size of the floccular lobe of the cerebellum is small in comparison
with that of lower animals, the Cercopithecidae standing in this
respect between these and the higher Apes with Man. The
fissures and convolutions of the cerebrum (neo-pallium) may now
be described in detail.

The two hemispheres are so symmetrical that the description
of the right will suffice for both (Fig. 46). The Sylvian fissure,
commencing inferiorly in a deep Sylvian vallecula runs upwards
and appears to terminate in the parallel sulcus which is continued
upwards to within 10 mm. of the upper border of the hemisphere.
The Sylvian fissure runs superficially only into the parallel sulcus,
for if the lips of the fissure are separated, a submerged gyrus will
be observed intervening between the two fissures. The end of
the parallel sulcus is received into the concavity bounded by the
curved intraparietal sulcus, which itself terminates in the typical
“ Aflfenspalte,” in the depths of which a submerged gyrus separates
it from the entirely submerged transverse occipital sulcus. The
intraparietal sulcus is joined by the external part of the internal
parieto-occipital sulcus. The ramus post-centralis superior of the
intraparietal is represented by a short isolated linear sulcus.

In front of the foregoing system will be observed the following
additional sulci ; the sulcus centralis, the lower end of which is
turned slightly backwards; the sulcus rectus (inferior frontal) with
a linear sulcus above it, representing the detached ascending limb ;
the triradiate sulcus arcuatus (inferior precentral) with a short
backwardly directed limb, which resembles the corresponding

CHAP. IV] THE GENERAL ANATOMY OF THE CERCOPITHECIDAE 07

sulcus in the genus Cebus (but not that in the genus Ateles).
Above these sulci (S. rectus and S. arcuatus) are two small

CENTRAL SULCUS

INTRAPAR1ETAL SULCUS

COMPENSATORY SULCUS

HIPPOCAMPAL FISSURE

Fig. 46. The left cerebral hemisphere of a Cercopithecus monkey (Cercopithe-
cidae). The main features are similar to those of the human brain : on the mesial
aspect the small post-splenial gyrus A. Retzii is not visible, and the fascia dentata
has not been exposed.

precentral sulci, the posterior one (nearer the central) being a
mere depression, the anterior being a linear sulcus. Below the
lower end of the central sulcus is seen a small linear sulcus which
may be called the transverse1.

1 Inferior transverse sulcus of Eberstaller.

5—2

68 THE GENERAL ANATOMY OF THE CERCOPITHECIDAE [SECT. A

On the orbital surface, the olfactory peduncle lies in a straight
furrow for its posterior half. The other sulci are two, an inner
triradiate, and an outer linear, the latter being directed obliquely
from within forwards and outwards. No distinct fronto-orbital
sulcus is seen.

The I’emaining sulci include an inferior temporal sulcus, in two
parts, one running in the long axis of the second temporal gyrus,
and the second being directed transversely to that axis. An
inferior occipital sulcus running on to the temporal margin is also
visible ; and the only remaining sulcus is at the occipital pole
and transverse and horizontal in direction.

On the mesial aspect (cf. Fig. 46) the following sulci require no
special description : the genual, the calloso-marginal, the internal
parieto-occipital, the “post-limbic” (which the internal parieto-
occipital does not join), and the calcarine sulci, and the hippocampal
fissure. The collateral is a single sulcus, and joins the calcarine
very superficially only. The posterior rhinal fissure here appears
as the incisura temporalis. If the crus cerebri be freely removed
it is possible to see some of the structures in the descending cornu
of the lateral ventricle, viz. hippocampus major and fimbria.

Alimentary System. In correspondence with the proportions
of the maxillary and mandibular skeleton, the tongue is elongated
and presents almost a truncated appearance anteriorly. The
tonsils are small. The oesophagus has much the appearance and
relations presented by the corresponding human structure, and on
its way to the stomach it grooves deeply the posterior aspect
of the left lobe of the liver. The latter organ is a simple sac,
whence a well-developed omentum resembling that of Man extends
downwards over the colon and small intestine (in one genus, viz.
Semnopithecus, the stomach is extraordinarily sacculated1. The
small intestine has the same general relations as in Man, being
attached to the posterior abdominal wall by a mesentery, distinct

1 In one genus of the family Cercopithecidae, the alimentary canal presents some
characteristic features. The monkeys thus distinguished belonged to the genus
Semnopithecus, of which many species have been described. The distinctive
features consist in (a) the extraordinary elongation and sacculation of the Stomach
and (b) an equally remarkable modification of the form of the Liver, which, in con-
sequence of the large size of the stomach, has been thrust across to the right side of

CHAP. IV] THE GENERAL ANATOMY OF THE CERCOPITHECIDAE 69

even in the duodenal portion of the gut, and passing (as in Man)
obliquely downwards from left to right. The mesenteric glands
are frequently enlarged in animals dying in this country, owing to
their having succumbed to tubercular disease. The caecum is
bluntly pointed and no vermiform appendix is developed. The
large intestine is characterized by the possession of a well-marked
mesentery for the ascending colon : the rectum is characteristically
straight with well-developed mesentery. The liver possesses all
the lobes distinguished in human anatomy, with the following
modifications. The right and left lobes are both subdivided, the
dividing fissure being much deeper in the left lobe ; the caudate
lobe is elongated and tapering, and like the spigelian lobe comes
into intimate relationship with the structures (portal vein, hepatic

the abdominal cavity. These features are represented in the diagram (Fig. 47) of
these organs in a Nasalis monkey (genus Semnopitheeus) .

Fig. 47. Viscera of a Nasalis monkey (Cercopithecidae) : the extraordinarily
modified form of the stomach and the consequent displacement of the liver to the
right are to be noticed. These features are found throughout the genus Semno-
pithecus, which includes many species of monkeys found in Asia.

70 THE GENERAL ANATOMY OF THE CERCOPITHECIDAE [SECT. A

artery and bile duct) which are situated at the right extremity of
the lesser omentum. The pancreas and spleen have similar relations
to those presented in the Hominidae, but it is to be noticed that
the spleen is covered to a very considerable extent by the liver in
consequence of the great development of the left lobe of this organ.

Respiratory System. The hyoid bone in tile Cercopithe-
cidae is characterized by the enlargement and downward extension
of the basihyal, which however is not excavated as in the Cebian
Mycetes (Howling Monkey). The laryngeal apparatus closely re-
sembles that of Man, all the muscles and cartilages of the human
larynx being easily recognisable. The lungs are more subdivided
than in Man ; in the left lung (Fig. 49) there are three lobes
corresponding in a general way to the three lobes normally found in
the right human lung. In the right lung (Fig. 48) the three lobes of

Fig. 48. fig- 49.

Fig. 48. Lateral aspect of the right lung of a Cercopithecus monkey (Cerco-
pithecidae) to shew the lobus azygos impar.

Fig. 49. Lateral aspect of the left lung of a Cercopithecus monkey (Cerco-
pithecidae). The heart is also shewn. The lung is divided into three lobes, thus
differing from the human lung of the left side, while resembling the right human
lung.

human anatomy will be found supplemented by a fourth lobe ; this
lobe, which is small and pendulous, is known as the lobus impar :
it is situated beneath the right bronchus and sometimes it sends a
process leftwards crossing the oesophagus anteriorly and thus en-
croaching on the posterior mediastinum and left side of the
thorax.

The heart is somewhat more mesial in situation than in Man.

CHAP. IV] THE GENERAL ANATOMY OF THE CE11C0PITHECIDAE 71

Thymic remains are visible on the anterior aspect of the pericar-
dium, which is also crossed by the right phrenic nerve.

Genito-urinary System. In a young specimen of a Cepha-
lopterus monkey (Cercopithecidae) the right kidney is situated
posteriorly to the left ; the right suprarenal body is elongated
and nearly cylindrical, the left being pyramidal in form. The
anterior renal surface is much more convex than the posterior
surface. Into the renal pelvis a single pyramid bulges distinctly,
though there are indications that a series of sections might reveal
more than one such protrusion. The genitalia are considered in
the two sexes separately.

A. The male. The testes in the foregoing example are still
situated in the inguinal canal, though close to the “external
ring”; it will be noted that the specimen though admittedly
young, nevertheless having acquired the first permanent teeth,
corresponds in age to human children of six to seven years.

The penis is protected by an elongated prepuce attached
far behind the glans, a fraenum praeputii being entirely absent.
The long penile urethra is supported by the cartilaginous “ os ”
penis, and terminates posteriorly in a distinct bulb, the latter
being well protected by the concrescence of the two ischial callosities
in the middle line of the perinaeum. The prostate gland is large,
unilobular, and firmly attached to the rectum as well as to the
urethra and base of the bladder.

The membranous urethra contains a distinct spheroidal caput
gallinaginis with lateral depressions.

The abdominal peritoneum is reflected almost horizontally for-
ward from the fundus of the distended bladder.

B. The female. The genitalia of a young female Cynocephalus
mormon provide material for the following notes. Externally, the
clitoris is so large as to constitute a penile appendage, which however
is imperforate, the urethral aperture being independent of this
organ. The prepuce is long and hood-like, cleft interiorly, and it
covers a distinct and bifid glans with crura and corpora cavernosa.
Like the body of this female penis however, the glans is imperforate.
The former is grooved posteriorly and the urethral orifice (meatus
urinarius) is still more posteriorly situated. The vagina is pro-

72 THE GENERAL ANATOMY OF THE CERCOPITHEC1DAE [SECT. A

portionately long and straight, without a hymen: its walls are
thrown into longitudinal folds, most distinct on the posterior
aspect.

The pouch of Douglas is shallow, and the rectum descends
almost vertically behind the uterus and vagina. No special
description of the uterus, tubes, ovaries, uterine and ovarian liga-
ments, or bladder is called for in view of their close resemblance to
the corresponding parts in the Hominidae.

The following list recapitulates characters which in the pre-
ceding account are of interest as affording explanatory evidence
of certain human morphological anomalies.

1. Fronto-maxillary suture on inner orbital Avail.

2. Fronto-squamous articulation at the pterion.

3. Rudimentary character of vertebral curves.

4. Additional rib-bearing vertebrae.

5. The list of muscles already given, cf. pp. 64, 65.

6. Large flocculus and floccular fossa.

7. Lack of vermiform appendix caeci.

8. Ascending meso-colon.

9. Caudate lobe of liver.

1 0. Lobus azygos impar.

Anthropoidea: Simiidae.

General Anatomy of Gorilla’. The skeleton, (a) The skull.
The first point to notice in an account of the skull of the Gorilla
is the great difference that exists between male and female in
the adult stages, and between the immature skull and the corre-
sponding mature stage in either sex. (Cf. Figs. 50, 51.) Museum
specimens are most frequently skulls of adult or aged male
individuals ; female skulls of adults, and quite immature skulls
of both sexes are next in frequency, and the skulls that are
the most profitable for the study of the typical features of the
male, viz. specimens that have not quite reached maturity, and
in which the permanent dentition is just about to be completed,
are the most uncommon. For this very reason such a skull will

1 Iu the Proceedings of the Zoological Society , 7th March 1899, will be found an
admirable comparison, by Keith, of the general systematic anatomy oi Chimpanzee
and Gorilla.

CHAP. IV]

THE GENERAL ANATOMY OF GORILLA

Fig. 50. Cranium, with mandible, of a young Gorilla (Simiidae) ; the first tooth
of the permanent set has appeared (permanent molar tooth). Note, in contrast to
Fig. 33, the comparatively large brain-case. There is no auditory bulla : the
auditory passage is long, but not so long as in adults : there are fronto-squamous
and fronto-maxillary articulations. Osseous ridges and crests are still undeveloped.

Fig. 51. Cranium, with mandible, of an adult Gorilla (Simiidae) : note the absence
of an auditory bulla, the presence of great bony crests; and of fronto-squamous
and fronto-maxillary articulations (the latter within the orbit in place of a lacrymo-
ethmoidal junction). The canine teeth are enormously developed in the male sex.

THE GENERAL ANATOMY OF GORILLA

[SECT. A

here be briefly described and the several features can be compared
with those of specimens in the Museums. The reason that skulls
of male examples fully adult or aged prove unsatisfactory is two-
fold : in the first place, fusion of the various cranial bones is very
precocious, and hence the relations and connections of the several
bones are obscured at a comparatively early period: secondly, with
maturity comes the immense development of bony ridges which
indicate the great mass of the temporal and nuchal muscles.
These ridges obscure the form of the brain-case.

If then we select as our example a specimen in which the
permanent dentition is all but complete, we shall find that the
last teeth to appear are the canines ; this condition offers a
contrast witli that which obtains in Man, but it must be admitted
that in the Gorilla the third molar is seen to break through in
many instances contemporaneously with the canine, so that the
difference is not absolute (v. infra, Chap. VI.). The skull remains
to be examined systematically and the following divisions are
convenient for this purpose.

A. The true cranial part, consisting of the bones (developed
mostly in membrane) which protect the cerebral hemispheres.

This part of the skull is ovate, longer and narrower (more
dolichocephalic) in the Gorilla than in either Chimpanzee or
Orang-utan, longer and narrower in the male than in the female
Gorilla. Relatively to the facial part, it is small, the reverse of
the human condition thus obtaining in the Gorilla. The coronal
suture is less tortuous laterally than in its middle portion, where
it meets the sagittal suture. The latter is quite tortuous until
the period of closure begins, when the interlocking processes are
reduced in length and the suture becomes simplified and straighter.
The lambdoid suture is tortuous (till closure begins) as far as the
temporal bone (the “ Asterion ”), thence downwards it is straight.
The line of suture between the parietal and squamous bones is
characteristically straight in its general direction, but the squamous
bone overlaps the parietal with long tongue-like processes. This
margin of the parietal bone is very distinctly longer than the
coronal margin, and herein is a notable difference from the human
skull. Wormian bones are not uncommon in the sagittal and
lambdoid sutures.

CHAP. IV]

THE GENERAL ANATOMY OF GORILLA

The muscular ridges have already been mentioned. In a nearly
mature skull they converge rapidly from the external angular
processes of the frontal bone, and each divides into upper and
lower lines, the upper of which actually meet at the bregma
though they diverge a little later. Herein a conspicuous difference
from aged examples is offered by the adolescent Gorilla, for in the
former the temporal ridges unite with one another to form a
great sagittally-directed crest which occupies the line of the
sagittal suture, and secondly, each temporal ridge combines with
the corresponding portion of the superior nuchal line to form
a similar crest which, running coronally and along the line of
the lambdoid suture, is traceable at each extremity as a ridge
which crosses the base of the stunted but massive mastoid process
to join the zygoma, of which it forms the posterior root.

The zygomatic arches themselves are strongly developed and
though not much bowed outwardly, yet the channelling of the
lateral cranial wall, especially along the line of the alisphenoid,
leaves a very capacious temporal fossa. From the lambda, the
contour-line of the skull descends sharply and obliquely forwards,
towards the foramen magnum, the obliquity being very charac-
teristic of the skull in all Simiidae.

B. In the facial portion of the skull the orbits first claim
attention. Bounded above by. a great supra-orbital ridge which
is continuous from one orbital margin to the other with scarcely
any interruption, and which has been described as resembling a
“ pent-house,” the orbits have a somewhat rectangular appearance,
and though the angles are rounded off, yet the general aspect
is quite distinct from the oval contour which characterizes the
orbit in Simia. In this respect the Chimpanzee agrees with the
Gorilla. The external angular processes of the frontal bone are
massive and project strongly, and this also contributes to the
square-cut appearance of this part of the face (Fig. 52).

The outer margins of the orbits are indistinct and bevelled.

The lacrymal bone is reduced as in Man and though abnormal
cases of a well-developed lacrymal hamulus occur, yet in general
this process is even more vestigial than in the human skull.
The laeryino-ethmoidal suture is usually replaced (65-4°/o as
against 34’6 °/0 of lacrymo-etlnnoidal sutures in a series of 26 males)

THE GENERAL ANATOMY OF GORILLA

[SECT. A

by a fronto-maxillary suture which may indeed be of considerable
length (10 mm.): the os planum of the ethmoid is reduced con-
siderably in vertical extent and is particularly attenuated anteriorly.

Fig. 52. Crania of Gorilla and Sitnia; the former is distinguished by the massive
brow-ridges which are continuous from one orbit to the other.

The number of infra-orbital foramina is variable, but the cases in
which a single foramen occurs are just in excess of the other
varieties.

The nasal bones are very characteristic in form, and are
conjoined at an early epoch. The combined bones form a single
element of the following shape. From a pointed apex on the level
of the supra-orbital ridge, the margins diverge for about 10 mm.
(at the level of the junction of the upper and middle thirds of the
orbit); below this they approach one another again, and here
a sharp crest projects from the middle line. Then the margins
diverge strongly and the crest is lost at the same time.

Finally the lateral margins for the last time converge, but
only slightly. The nasal bone thus extends well below the level
of the orbits, and their shape distinguishes the bones in the
Gorilla equally from those of the Chimpanzee and the Orang-utan.
(Cf. Figs. 53, 54, 55.) The lateral margins of the apertura pyri-
formis nasi are clearly formed by the premaxillae which extend
up even along the sides of the nasal bone. They are rounded,
and the lower margins of the nasal apertures are quite indistinct.
No definite nasal spine is seen, but sometimes a small tubercle
occurs and in a good many cases the premaxilla throws off paired
backwardly-directed processes to meet the nasal septum : these
processes must not be mistaken for a true nasal spine, though
suggestive of that structure. The alveoli of the great canine teeth

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

hZ-J-2.

Fig. 53. Nasal bones of Simiidae ; (A) Gorilla, (B) Chimpanzee, (C) Orang-utan.

Fig. 54. Fig. 55.

Fig. 54. Nasal bones and intermaxillary (premaxillary) bone of a young Gorilla.
Fig. 55. Diagram of the nasal bones and premaxilla in the preceding figure.

THE GENERAL ANATOMY OF GORILLA [SECT. A

form projections on the facial surface on each side of the nasal
aperture.

The palate has the characteristic long hypsiloid anthropoid
contour, and the post-palatine spine is usually replaced by a notch.
There is usually some irregularity in the arrangement of the
sutures on the palatine surface, whereby the common cruciform
appearance is distorted. The tuber maxillare is usually small, and
the anterior palatine foramen (whence the pre-maxillo-maxillary
sutures spring) is characterized by not receiving the lateral fora-
mina (for the anterior palatine arteries).

The temporal fossa is very deep and capacious ; the alisphenoid
deeply channelled, and often attenuated above, in correlation with
the common arrangement of a fronto-squamous articulation re-
placing the parieto-sphenoid junction (of the Orang-utan, of Man,
and of the Cebidae and Lemuroidea): herein some of the lower
human races and the Cercopithecidae agree with the Gorilla.

The infra-temporal crest is very small, and the spheno-
maxillary fissure much narrowed as in the other Simiidae, which
in this respect (and the concomitant approximate completion of
the post-orbital wall) are more highly specialised than Man or the
Lemuroidea. Sometimes the malar bone does not close in the
end of the spheno-maxillary suture, but there is here a spheno-
maxillary suture.

The base of the skull offers a few points worthy of special
note. Anomalous processes, such as the third occipital condyle,
or ossification in the suspensory ligament of the axis, and the
like, are rare. The condyles are short and the foramen smaller
than in Man, even in skulls absolutely larger than the human
skull. The glenoid fossa is very shallow and to its inner side
is a great endo-glenoid tubercle. The anterior lacerate foramen
is commonly closed by osseous deposit, and the styloid process is
diminutive. The tympanic bone is long and semi-cylindrical, and
has no bulbous inflation.

The teeth are of the typical number (f{ff). The canines are
enormous in the males : the premolars have commonly three roots
in the upper jaw ; the molars bear four very clean cut (“ crystalline ”
Dr Keith calls them) cusps in the maxilla ; and in the mandible,
a “ talon ” may bear two additional cusps. The third molar is

CHAP. IV] THE GENERAL ANATOMY OF GORILLA 79

already shewing signs of reduction in the maxilla, despite the
statements in certain works on this subject (and the Chimpanzee
shews a further advance on this condition of reduction). Accessory
teeth are not uncommon. First come accessory molars in the
maxilla, then remnants or rudiments behind the premolars in the
maxilla. An unique case in the Hamburg museum shews a
double canine tooth and sometimes a fifth incisor (of large size
and so probably not a retained milk tooth) is seen in the mandible.
Further details as to the dentition are provided and commented
upon in Chapter VI.

The mandible is large and heavy, with no mental prominence,
but a retreating chin, and deep symphysis. The genial tubercles
are commonly represented by a single sharp ridge. The lower
incisors project forwards and the molars have well marked cusps
which may be as many as six in number. The sigmoid notch
is shallow.

The foregoing notes refer particularly to the skull of a
young male animal. In older males great crests are developed,
sutures are obliterated, the air spaces in the maxilla (antral)
increase, and the crowns of the teeth are worn smooth. In
females the permanent conditions resemble more closely those
just detailed, for the ridges never attain a high grade of de-
velopment. Very immature specimens on the other hand differ
in the lesser relative development of the facial skeleton and the
greater size of the brain-case, features which approximate them
more closely than adult examples of the human type. In fact
from a very early period the gorilla type diverges from the human
type, and the divergence henceforward becomes more marked with
the lapse of time.

Skeletal System. The skeletal system (other than the skull)
will be described in the following order. The vertebral column
will be first considered, then the anterior limb-girdle and its limb
and finally the posterior limb-girdle and limb.

In the cervical region of the vertebral column the enormous
length of the vertebral spines is the most striking feature : these
spinous processes are not however bifid, and thus differ from those
of the human races of Europe although approached in this respect
by the cervical vertebrae of some of the primitive human races.

THE GENERAL ANATOMY OF GORILLA

[SECT. A

The costal process is sometimes imperfect, so that there is no
canal between it and the true transverse process. The costal
process of the sixth cervical vertebra is large, while that of the
seventh is very small, the same proportions obtaining as in Man.

In the thoracic region thirteen vertebrae are common, though
occasionally fourteen rib-bearing vertebrae occur. Their centra
appear as though laterally compressed (in comparison with those
of Man) : the transverse processes appear stunted but. massive :
the spinous processes of the lower members of this series tend to
be bifurcated. The section of the thorax in the horizontal plane
differs from that of Man in the relatively larger proportion borne
by the antero-posterior to the transverse diameter. The thorax
is thus intermediate between the human and the pithecoid type
as shewn by Cercopithecidae.

The usual number of lumbar vertebrae is three, although four
vertebrae are of frequent occurrence.

The lumbar centra are vertically higher and transversely
narrower than those of Man. While the lateral and mammary
processes are well-developed, the accessory is insignificant. Anapo-

Fig. 56.

Fig. 57.

conca^tyof this' part of the vertebral column is to be noted. Cf. also Fig. 40 for

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

physes are not seen, but they sometimes occur in the Orang-utan.
(Cf. Fig. 56.)

The “ transverse ” process of the third lumbar vertebra is small
in comparison with the others and thus differs from its repre-
sentative in Man. The interlocking of the vertebrae brought
about by the superior articular processes of one vertebra em-
bracing the lower processes of the vertebra above is much less
effective and complete than in Man ; for the former processes
do not extend so far round the latter as in Man and their
hold is correspondingly more feeble. This may be represented
diagrammatically as in Fig. 57. The differences between the
vertebral columns of Man and Gorilla are extraordinarily well-
marked in this region, which is profoundly modified in corre-
spondence with the difference between the erect attitude of Man
and the crouching one of the anthropoid ape.

The sacrum of the Gorilla consists usually of six pieces, of
which the laminae unite posteriorly with remarkable constancy and
regularity : the variety of spina bifida which consists of a lack
of union of these laminae is thus of infrequent occurrence. A well-
marked sacral notch is usual, and is due to the comparative
attenuation of the second sacral vertebra1. The coccyx is rudi-
mentary as in Man. The sacral index2 is stated by Turner to be
72 (Homo 112): and the curvature is small, the average depth of
the sacral curve being 10'4 mm. (Paterson) as against 251 mm.
in the (white) Hominidae.

A general review of the characters of the vertebral column
shews that the Gorilla differs from Man in respect of the degree
of anterior lumbar curvature. As regards the vertebral foramina,
these are throughout more circular in outline than in Man ; nor as
regards the centra of the vertebrae does the Gorilla shew in the,
cervical and lumbar regions the marked excess of the transverse
over the sagittal diameter so characteristic of the corresponding
human vertebrae.

The pelvis is elongated antero-posteriorly (i.e. from iliac crest
to tuberischii) in comparison with that of Man.

The iliac crests are more tortuous and the iliac fossae more

1 Cf. Paterson, The Human Sacrum, p. 132.

2 v. infra. Chap. xii.

D. M. 6

THE GENERAL ANATOMY OF GORILLA [SECT. A

distinct than in any other anthropoid ape, though less so than in
Man, and an anterior inferior-iliac spine is sometimes found (cf.
Chap. xil). The posterior parts of the ilia are undeveloped as
compared with Man. The ischial tuberosities are less massive
than in Man. The Os innominatum is long, and deficient in iliac
breadth when compared to the corresponding human bone. The
pelvic brim is, relatively to its sagittal diameter, much narrower
than that of Man. The femur is short, stout, straight, and the
shaft entirely lacks the linea aspera which is so characteristic of the
human femur, being flattened sagittally. The neck is short, and the
articular surface of the head less extensive than in Man. It makes
an angle of about 124° with the shaft. In Man this angle varies
from 128° — 141°. As in Man (hut unlike the condition in the
Orang-utan), the ligamcntum teres is found. In the knee-joint

Fig. 58. Posterior aspect of the knee-joint of a young Gorilla (right limb),
shewing the annular form of external articular cartilage.

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

the external cartilage is annular, not serai-lunar (cf. Fig. 58). No
soleal line is seen on the tibia, and the plane of articulation with
the astragalus is very oblique. The fibula is very slender and its
malleolus small. The calcaneum is longer and larger than in the
other Simiidae, but even thus, it falls far behind that of Man in
these respects. The first meta-tarso-tarsal articulation is clearly
a ginglymus joint, and contrasts strongly with that of Man, the
difference being evidently referable to functional adaptation.

The scapula contrasts strongly with that of Man in respect
of the large extent of the supraspinous fossa. The scapula other-
wise resembles the human scapula more closely than do those of
the Chimpanzee, or the Orang-utan. Paradoxically, the clavicle
is comparatively weak and slender, lacking as it does the bold
curves and distinct muscular markings of its representative in the
Orang-utan. The humerus is characterized by a similar lack of
definition as regards the evidence it bears of the attachment of
muscles and ligaments : thus the deltoid muscle makes but little
impression on the shaft, which indicates the comparatively small
size and functional activity of this muscle in the Gorilla. The
average figure representative of the angle of torsion of the humeral
shaft is given by Broca as 141°, European Hominidae having an
average of 161°.

The olecranon fossa of the ulna is very frequently perforated
(in about 80 °/0). The shafts of the radius and ulna are not so
straight as in the corresponding human bones, and consequently
the intermediate space is more extensive. In the carpus, the ossa
centrale and radiale fuse as in Man (unlike their condition in the
Orang, Hylobates and in the Cercopithecidae) to form the scaphoid
bone of the wrist.

The sternum is flat (latisternal) and the junction of pre-
and meso-stemum more commonly occurs at the level of the 3rd
costal cartilage than in Man, but less usually than in Hylobates.

The following numerical data are taken from Aeby’s work on
the Osteology of the Gorilla1.

Proportions of the several segments of the limbs :

Upper limb: Arm 41T °/0. Forearm 327 °/0. Hand 2(32 °/o-
Lower limb: Thigh 41 3 °/o- Leg 30'5 °/o- Foot 28‘2 °/o-
1 Cf. Gegenbaur’s Ja hr buck, Band 4.

6—2

84 THE GENERAL ANATOMY OF GORILLA [SECT. A

Muscular System. The muscular system now claims atten-
tion and will be considered in the same way as in the accounts of
the Lemuroidea and the Cercopithecidae.

The muscles correspond severally with very close accuracy to
those of Man, and in fact the number of distinctive human muscles,
at one time thought to be thirteen, is now reduced to three (M.
plantaris, peroneus tertius and serratus posticus inferior). The
acromio-trachelian and latissimo-condyloideus muscles distinguish
the Gorilla, not being normal in Man.

While a general agreement in the individual muscles exists,
there is a definite distinction to be drawn as regards their rela-
tive development in Man and in the Anthropoid Apes. Thus
while Man is characterized by the development of the musculature
of the lower limb, in the Gorilla that of the upper limb has been
developed. The musculature of the upper limb bears to that of

the lower limb the proportion of — ■ ^ by weight in the Orang-utan

(the proportion in the Gorilla will be about the same), while the

proportion in Man is jL At the same time, when the upper limbs

of the Gorilla and Man are compared, it will be seen that in the
Gorilla the extensor series of muscles falls for behind that of Man
in relative development (16°/o instead of 22 °/0 of the total muscu-
lature1).

The following notes deal with individual muscles in the
Gorilla.

As regards the panniculus system (cf. Fig. 59), the diffe-
rentiation of the muscles of facial expression has reached to nearly
the same point as in Man: the platysma muscle is extraordi-
narily thick and distinct.

The origin of the M. latissimus dorsi is of particular interest,
in view of the relation of this muscle to movements involved by
an arboreal mode of existence ; the muscle arises from the tenth
and succeeding vertebral spines, and in its attachment to the
crista ilii is found to be much more extensive than in Man,
for it arises along the whole length of this bony crest (in the
Chimpanzee it may even encroach upon the region of Pouparts

1 Langer: Mitt, der Anthr. Gcs. in Wien.

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

ligament). The tendon of insertion has similar relations with that
of M. teres major to those described in the Cercopithecidae (v. supra).

Fig. 59. Facial musculature of an adult Gorilla. Note the great development
of the anterior fibres of the platysma. The specimen forms part of the Holt dona-
tion to the Cambridge Collection.

The so-called Achselbogen muscle is rare. On the other hand, the
lowest fibres of the pectoral mass commonly constitute an inde-
pendent muscle, the M. pectoralis abdominalis1. (Cf. Fig. 60.)

The M. biceps femoris commonly consists of two distinct
portions, as in Chimpanzees. (Cf. Fig. 61.)

The M. gluteus maximus arises from a fascia covering the
M. gluteus medius, from the posterior part of the iliac crest, from
the sacrum, greater sacro-sciatic ligament, and tuber ischii ; the
sacral portion is the largest, and the ischial part has been described
as a separate muscle, the M. ischio-femoralis (Duvernoy).

The adductors of the thigh comprise four muscles arranged
in the following manner (Deniker).

The M. adductor primus corresponds to the M. adductor longus
of human anatomy, and is attached to the horizontal ramus of the

1 Cf. Windle, “The Pectoral Group of Muscles,’’ Trans. Hoy. Irish. Acad. vol.
xxix. part xii.

THE GENERAL ANATOMY OF GORILLA [SECT. A

Os pubis and not to the body of that bone, as in Man. The
M. adductor secundus corresponds to the M. adductor brevis of
Man, and is attached to the body of the Os pubis. The M. adductor
tertius (corresponding to the upper part of the M. adductor
magnus) of Man is attached to the descending ramus of the pubis
and also to the linea aspera of the femur. It sends a slip to the
M. adductor secundus.

Fig- 60. Fig. 61.

Fig. 60. A dissection of the ijectoral and axillary regions in an adult Gorilla ;
the references are as follows :

1. M. peetoralis abdominalis (chondro-epitrochlearis). 2. M. pectoralis
major (cut). 3. M. pectoralis minor. 4. Laryngeal sac extending into the
axilla. 6. Tendon of M. latissimus dorsi, with the M. latissimo-condyleus
extending down the arm.

Fig. 61. Dissection of the outer side of the thigh of an adult female Chimpan-
zee, shewing the two heads of the M. biceps : also the great sciatic nerve and its
division.

Lastly, there is the M. ischio-condyleus, which corresponds to
the condylar portion of the M. adductor magnus of Man. The
separate existence of this ischio- condylar muscle is very charac-
teristic of Cercopithecidae and Simiidae. It encroaches at its

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

insertion (as has been already said) upon the popliteal area of the
femur.

The M. psoas minor is variable in its occurrence, being rather
more frequently absent (60 #/o) than present (40°/0) (Keith).

The M. soleus is of interest, inasmuch as it has been found in
the Gorilla with an occasional tibial origin. Otherwise it follows
the rule for Cercopithecidae, and has an exclusively fibular origin.

The M. plantaris never appears to be developed in the Gorilla
as a separate muscle, although it is of common occurrence in the
Chimpanzee.

The M. flexor accessorius digitorum (M. quadratus plantae) is
rare, though it has been found in Gorilla (its mode of insertion
in the Simiidae is also unlike that of Man, as it may in Chimpanzees
form an attachment to the tendons of the M. flexor brevis digitorum).

The tendon of the M. flexor brevis to the little toe is frequently
absent.

The pedal interosseous muscles are grouped about the third
digit, and herein the Gorilla differs from Man and resembles the
Chimpanzee, the Orang-utan, some varieties of Gibbon, and the
Cercopithecidae generally : it must be admitted that many Gorillas
possess the human arrangement, these muscles being then grouped
about an axis formed by the second digit. In this respect the
Gorilla is in a phase of evolution which is transitional and inter-
mediate between Hominidae and the other Simiidae1.

The deltoid muscle is characterized by the close connection
between the fibres and those of the M. triceps brachii.

The M. coraco-brachialis is frequently double2, and consists
then of a long and a short portion. The muscle may be found
conjoined with (a) M. latissimus dorsi, (6) M. triceps or (c) M.
brachialis anticus. It has been recently suggested3 that in respect
of the M. biceps humeri the Simiidae are more highly specialised
than the Hominidae ; the evidence rests on the reduction observed
in the lacertus fibrosus, or fascial expansion of the tendon of inser-
tion ; the Simiidae seem to have passed through a stage of evolution
in which the muscle in question possessed three heads of origin.

1 The M. contrahentes are rare in Gorilla (Keith, Proc. Zool. Soc. 1899,
March 7).

2 It is however single in the adult Gorilla (Cy) dissected by the writer at Cambridge.

Gronroos, A bit. der Akad. der Wise. zu Berlin, 1903.

THE GENERAL ANATOMY OF GORILLA [SECT. A

The chief characteristic of the M. teres major is the occasional
gi’eat breadth of its scapular attachment.

The tendon of the M. flexor longus pollicis is sometimes absent,
sometimes represented by a mere thread arising from the tendon
of the deep flexor of the index, or from the anterior carpal ligament.

The M. extensor minimi digiti is represented by a tendon from
the M. extensor communis digitorum.

The M. extensor indicis resembles its counterpart in Man. As
for the extensors of the pollex, it is noteworthy that a M. extensor
brevis pollicis, though by no means constant, is nevertheless
sometimes met with. This is another instance of a transitional
phase in the evolution of a series of muscles and tendons.

The diaphragm is characterized by the large proportions of the
tendinous part, which leaves but a narrow zone of muscular fibre
around its periphery. The pillars of the diaphragm are arranged
as in Man.

Nervous System. The features of the brain of the Gorilla
very nearly reproduce those of the human brain. The differences

I r)tra parietal sulcus

Sulcus ! |

lurjatus

Ir^erior
occipital
Sulcus

C eiytra l sulcus

(Rol)

, lrjsula\

c • '

Fissure

o-f Sylvius

"7^- Urryitirjg

Sulcus

'Parallel (

Sulcus (post lirr^J olf •£)

of'Keil

\MFul Ooot°-or(,,1alJ

Fig. 62. Lateral aspect of the right cerebral hemisphere of a young Gorilla
(Simiidae). The olfactory nerves are attenuated in point of size: the cerebral
surface is much more convoluted than in the preceding examples and recalls the
appearance of the human cerebrum. Of. with lugs. 20, 2d, 21, 25, and p. 68.

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

are chiefly those of absolute size, and the Gorilla-brain has not
attained to such a high degree of development, as regards the
amount and the complexity of convolutions of the cortex, as
the brain of Man. When compared with the other large anthro-
poid apes, the Gorilla is seen to stand in a position nearer to
Man than these. There is however in the Gorilla a marked
sexual difference in the size of the brain. In general form

(cf. Fig. 62) the cerebrum is ovoid, and strongly rostrated
anteriorly, the frontal lobes being deeply excavated interiorly
by the upward projection of the orbital plates of the frontal bone.
The frontal lobes are thus less full and rounded, both absolutely
and proportionately, than those of Man. The occipital end of the
hemisphere does not overlap the cerebellum to the same extent as
in Man, and the cerebrum is smaller in proportion to the cere-
bellum than in the human brain. The following notes are based
upon Professor Elliott Smith’s description of the brain of a
Gorilla in the Museum of the Royal College of Surgeons. At
the base of the brain the posterior rhinal fissure is retained with
diagrammatic clearness, and thus demarcates the neo-pallium from
the pyriform lobe. There is a deep vallecula Sylvii, which leads
into the stem of the Sylvian fissure. The latter is foi’med by the
meeting of temporal and orbital opercula as in the human brain.
As these opercula extend laterally they diverge, and expose a
small triangular depressed area of insula. The orbital operculum
is limited by a distinct fronto-orbital sulcus, which is really the
anterior limiting sulcus of the insula. A dorsal opercular fold
demarcates the lateral (superior) margin of the insula, and makes
so complete a superior limiting fissure, that it appears to join the
anterior limiting (fronto-orbital) sulcus, though closer examination
reveals a strip of cortex dividing the two sulci. In most brains of
Gorilla this strip is wide and quite easily seen. The mesial end
of the fronto-orbital sulcus does not usually join the stem of the
Sylvian fissure. The orbital surface of the frontal lobe is marked
by a tri-radiate orbital sulcus to which smaller sulci may be
accessory. The central sulcus presents a well-marked “ genu.” On
the lateral surface of the frontal lobe, well-marked representatives
of the sulci rectus and arcuatus are seen, and are evidently
representative of the inferior frontal and inferior pre-central sulci

THE GENERAL ANATOMY OF GORILLA

[SECT. A

of human anatomy. The superior pre-central and superior frontal
sulci are arranged almost diagrammatically. A small sulcus frontalis
medius and a representative of the sulcus fronto-marginalis (of
Wernicke) may occur. The inferior transverse sulcus is commonly
absent, but Eberstaller’s sulcus diagonalis occurs.

The parallel sulcus is hooked round the extremity of the
Sylvian fissure, much as it is in the Cynocephalous apes. The
intra-parietal sulcus is clearly recognisable : the ramus post-
centralis superior is commonly independent of the last-named
sulcus which dips posteriorly under the occipital operculum. The
arcus occipitalis is very large, and wholly exposed, the mesial end
of the occipital operculum having been pushed completely outward
and backwards. A Y-shaped lateral occipital sulcus cuts into the
occipital pole of the hemisphere. The occipital operculum is
bounded by an almost semicircular Affenspalte.

The calcarine sulcus (cf. Fig. 63) consists of an anterior deep
(true calcarine) portion, and a shallower retro-calcarine element,
the latter being strongly inflected at its posterior end. A dorsal
post-calcarine sulcus runs parallel to this last-mentioned portion.

The sulcus parieto-occipitalis of the mesial aspect is constant
in occurrence, but very variable in extent and connections. The
collateral sulcus may join the posterior element of the occipito-
temporal sulcus, and operculation occurs in this region as it does
in the genera Cynocephalus and Macacus. The calloso-marginal
sulcus is very complete, and Broca’s “ compensatory ” sulcus also
occurs.

The cerebellum closely resembles that of Man. The floccular
lobe however is larger than in human brains, and consists of
two lobules each attached by its own stalk. Of these one, the
mesial, is much the larger and is composed of three separate groups
of folia whose separate peduncles unite in a common stalk. The
lateral lobule is smaller and almost hidden by the former. It
represents the flocculi secondarii of Man, which may correspond to
the paraflocculus of lower mammals. The olivary body is in
contact with the lower margin of the pons. No trapezoid body is
exposed. The mesial geniculate body appears in some cases to be
much more prominent than in Man (a prominence possibly associ-
ated with the larger size of the auditory nerve).

CHAP. IV] THE GENERAL ANATOMY" OF GORILLA

Though it is not possible to enter here upon the physiology of
the brain of Gorilla, yet it must be mentioned that in experiments

iracT

^ippoca rr\pa |

./ fissure

^b'DQi fissure.

O'f.

Insula
e-x posed

Fig. 63. Mesial (A) and frontal (B) aspects of the right cerebral hemisphere
of a Gorilla (from a specimen in the Anatomy School at Munich). Note the very
great similarity in appearance, as regards the mesial aspect, to the human cerebral
hemisphere. The rhinal fissure (incisura temporalis) is conspicuous. In (B) note
the uncovered state of the insula and the lack of definite anterior limbs of
the fissure of Sylvius.

undertaken with a view to the investigation of cerebral localization,
the brain of this anthropoid, when examined by Sherrington and
Griinbaum, yielded the startling evidence that the motor areas of
the cortex are exclusively situated posteriorly to the central fissure.

THE GENERAL ANATOMY OF GORILLA

[SECT. A

This result contradicts those obtained by earlier observers who
have examined the brains of other anthropoid apes, and par-
ticularly necessitates a revision of the statements of Horsley
and Beevor with regard to cortical cerebral localisation in the
Orang-utan. At the same time, it must not be forgotten that
considerable individual, not to say specific, variation may exist,
and a fuller knowledge of the facts may lead to an explanation on
these grounds of this discrepancy in observations.

The peripheral nervous system offers a certain number of
differences from that of Man :

The following list given by Eisler1 shews some of the chief
divergences from the normal human arrangement of nerves pre-
sented by the Gorilla.

The facial nerve is more complicated in the Gorilla than in the
Chimpanzee, but less so than in the Orang-utan and in Man : its
communications with the external carotid plexus are richer than
in Man.

The glosso-pharyngeal nerve communicates freely with the
tenth, twelfth, and sympathetic nerves. It may consequently
appear deficient in pharyngeal branches.

The ramus internus of the superior laryngeal branch of the
Vagus may perforate the thyroid cartilage.

The ramus descendens hypoglossi contributes to the innerva-
tion of the sternomastoid muscle. The ansa hypoglossi receives
branches from the first two cervical nerves.

The great auricular and the superficial cervical nerves come
from the second cervical only, the supra-clavicular from the second,
third and fourth cervical nerves.

The phrenic nerve contains sympathetic fibres.

The supra-scapular nerve comes from C. IV. and C. V. (C. v.
and C. VI. in the Hominidae).

The nerve to the M. subclavius is not a distinct entity. The
internal cutaneous nerve is derived principally from the first thoracic
and intercosto-humeral branch of the second thoracic nerves.

The musculo-cutaneous nerve receives no contribution from
C. vii. ; it supplies the M. coraco-brachialis, but does not perforate it.

1 “ Muskeln und periphere Nerven des Gorilla.” Plalle-a-S. Exhaustive de-
scriptions have also been published by Bolk, Sperino, and Kohlbriigge.

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

Fine vascular branches are supplied to the brachial artery by
the ulnar, as well as by the median nerve ; the deep volar branch
of the ulnar nerve springs from a communication between the
ulnar and median nerves, and passes beneath the ligamentum
carpi volare proprium to enter the hand.

The median nerve passes beneath the M. pronator teres.

The upper cutaneous branch of the radial nerve is absent, and
its place is taken by a twig from the circumflex nerve ; the radial
nerve does not perforate the M. supinator brevis. The ilio-hypo-
gastric and ilio-inguinal nerves arise from the thirteenth thoracic
nerve, which is accordingly considered by Eisler as representative
of the first lumbar nerve of Man.

The anterior crural nerve receives most of its muscular fibres
from L. IV.

No contributions to the sciatic portion of the sacral plexus come
from nerves posterior to the second sacral.

The pudendal plexus is formed by the second and third sacral
nerves, the coccygeal plexus by S. IV. and S. v.

The long pudendal and inferior haemorrhoidal nerves are com-
pletely independent of each other.

The anterior tibial nerve supplies (in correlation with the
shifting fibula-wards of the dorsal interosseous muscles) the
opposed surfaces of the second and third toes.

In the sympathetic chain three cervical ganglia are found, in
addition to the ganglion stellatum ; the second and third ganglia
are placed more anteriorly than in Man.

The sympathetic chain, the splanchnic nerves, and the vena
hemiazygos pass together through the diaphragm.

A ganglion meseraicum medium, not found in Man, lies between
the aortic and coeliac plexuses.

In many instances a single sympathetic ganglion is connected
with two or more spinal nerves, and vice versa a single spinal nerve
may send contributory fibres to two sympathetic ganglia.

The general distribution of cutaneous nerves to the lower limb
of a Chimpanzee is shewn in the accompanying illustrations. (Figs.
64, 65, 66.)

THE GENERAL ANATOMY OF GORILLA [SECT. A

Fig. 64.

Fig. 65.

CHAP. IV]

THE GENERAL ANATOMY OF GORILLA

Figs. 64, 65, 66. Dissection of the lower limb of a Chimpanzee to shew the dis-
tribution of the cutaneous nerves. Note the lack of cutaneous fibres from the
obturator nerve, and the absence of filaments from the anterior tibial nerve to the
cleft between the hallux and first toe.

THE GENERAL ANATOMY OF GORILLA [SECT. A

Alimentary System. The tongue is elongated, is not pointed,
but has a nearly rectilinear anterior margin. The relation of its
breadth to its length is stated by Ehlers to be as 1 : 36.
Fungiform, filiform and caliciform papillae, the latter commonly
numbering five, are found on its upper surface. Posteriorly
to these are numerous conical papillae. A lingual fraenum is
found, as well as two folds which guard the orifices of the Wharton-
ian ducts, and which are occasionally well developed in Man.
There is also another fold corresponding to the plica fimbriata of
Gegenbaur, and which is said to be developed in the larger Anthro-
poid Apes and in Man but to be lacking in the Cercopithecidae
and Cebidae. Palatal folds or ridges are also seen. The salivary
glands (parotid and sub-maxillary) have approximately the same
relations as in Man.

The stomach is a simple sac, having similar relations on the
whole to those of the human stomach, with the exception that as
regards the transverse colon the human stomach is higher, that of

Fig. 07. Diagram (to scale) of the relations of the stomach and large intestine
in an adult male Gorilla (“ Cy ”).

Hepatic

(\txure

CHAP. IV] THE GENERAL ANATOMY OF GORILLA

the Gorilla being often lower and thus rather behind than above
the transverse colon. In the adult Gorilla the human arrange-
ment may however obtain. (Cf. Fig. 67.)

The small intestine is quite distinct in appearance from the large :
the relative lengths of these two portions of the gut vary in the follow-
ing way; in a foetus of 5 months the length of the small intestine was
to that of the large intestine as 3 to 1 ; in a young Gorilla the propor-
tion 4’8 to 1 has been found, and in an adult Gorilla the proportion of
2'1 to 1 obtained. There would thus appear to be irregularity in the
rate of growth of each portion of the gut, and the irregularity is
of a reciprocal kind. The general characters of the intestine do
not differ materially from those of the human intestine. Deniker
suggests that in the Gorilla the vermiform appendix caeci increases
in relative size with the age of the animal, whereas it decreases with
age in Man. (For the position of the caecum cf. Figs. 67 and 68.)

Fig. 68. Abdominal and pelvic viscera of an adult male Gorilla, seen from the
right side. Note the extent to which the caecum and appendix have descended into
the pelvic cavity. (Holt donation ; Mus. Anat. Cant.)

The pancreas does not differ apparently from that of Man : the
characters of the spleen however are distinctive, the most striking
being the extreme attenuation of this organ in its lower parts, so
that its extremity is tapering and caudiform.

D. M.

THE GENERAL ANATOMY OF GORILLA

[SECT. A

The liver of the Gorilla (cf. Fig. 69 ; the inferior aspect of the
liver of a young Gorilla is represented) differs from those of the
other large anthropoids and of Man in the important character of
the tendency to subdivision of right and left lobes, a character

lobe

Sp,o

Caudate
lobe

Fissures
Some+i rne-s

Seer^ uj

l)wrr)ar)

"foetal live

bladd

hssures i 13d! cation

partial Subdivision of
cwjd left lobes

Fig.

09.

which assigns a comparatively lowly place to the Gorilla in a
comparison of the higher Primates based on the anatomy of the
liver.

The general relations of the peritoneum are the same as those
of Man.

Vascular System. The heart closely resembles the human
organ : in respect of length it bears to the stature a slightly
higher ratio than is the case in Man. The differences between
the arterial system of the Gorilla and Man are few and insig-
nificant. The arrangement of the great arteries springing from
the arch of the aorta is identical with that of Man in 89 °/o of
examples. The lingual artery may arise from the facial, as is

CHAP. IV] THE GENERAL ANATOMY OF GORILLA 99

sometimes the case in Man. In the hand, the superficial palmar
arch is frequently incomplete through the failure of the superficial
branch of the ulnar artery to supply more than two and a half
digits, the remaining two and a half being supplied by an enlarged
A. superficialis volae. In the lower limb, a striking difference
from the human arrangement of artei’ies is provided by the
saphenous or internal tibial artery, which in many anthropoids
replaces the anterior tibial artery of Man, and corresponds exactly
to the radial artery in the upper limb.

In other respects the general arrangement of vessels is similar
to that which obtains in Man. The following notes taken from
Eisler’s work1 shew that individual examples may present con-
formations met with in Man as anomalies only. Eisler states that
the heart of Gorilla is placed further to the left than in Man.

The posterior auricular and the occipital arteries arise by a
common stem.

The ulnar artery passes deeply to the anterior annular ligament
(not over it as in Man) and proceeds beneath the piso-unciform
ligament with the ulnar nerve.

Both the superior intercostal arteries and an arteria trachealis
azygos (thyroidea ima) spring from the arch of the aorta.

The middle sacral artery gives off two lumbo-sacral arteries
and then divides into two lateral sacral vessels.

The dorsalis pedis artery is largely, sometimes entirely, replaced
by the long saphenous artery already described.

The following statements refer to veins.

Among the superficial veins of the forearm and arm only the
cephalic vein occurs constantly as a distinct trunk.

I he superior intercostal vein opens into the vena cava superior
passing anteriorly to the aorta. No communication is made with
the subclavian vein.

The eighth intercostal vein of the left side passes anteriorly to
the aorta and into the vena azygos.

A deep saphenous vein supplements the long saphenous vein
in the thigh and accompanies the arteria saphena magna (long
saphenous artery).

1 Eisler (op. tit. p. 121).

7—2

100

THE GENERAL ANATOMY OF GORILLA [SECT. A

Respiratory System. The hyoid hone of the young Gorilla
becomes ossified at a relatively earlier epoch than that of Man,
possibly in relation to the development of the laryngeal pouches
in the former. The laryngeal pouches (cf. Fig. 60) are enormously
dilated laryngeal ventricles, which pass out outwards through the
thyro-hyoid membrane of each side and extend downwards as far as
the axillae, passing beneath the clavicle and the pectoral muscles.

The bronchi are less divergent than in Man : their ultimate
division is quite similar to the human arrangement. The division
of the lungs resembles that obtaining in the Hominidae, and the
lobus azygos impar is occasionally though not always found.

The thyroid gland is situated rather higher up on the trachea
than in Man : the isthmus may be distinct, though this feature
varies. The thymus is voluminous in the foetus at 5 months : its
disappearance would appear to be more rapid than in Man.

Genito-urinary System. The Genito-urinary system offers no
important differences from that of Man.

The kidneys may present but a single pyramid as in Hylobates,
but this is a variable character in Gorilla. The genitalia of the
female differ in arrangement from the human type, inasmuch as
the vulva is directed posteriorly. The vagina, uterus, Fallopian
tubes, and ovaries resemble the human organs. The existence of
a hymen is denied by various observers: this membrane would
thus appear to characterise the Hominidae alone among the
Primates.

In the male, the glans penis is smaller relatively and absolutely
than that of Man, but is nevertheless more distinct and relatively
larger than in other Simiidae. There is an os penis, as in the lower
Primates, and other Eutherian mammals. The Hominidae amongst
Primates alone would seem to be characterised by its absence.

Integumentary System. Cutaneous grooves on the palms
of the hand and the soles of the feet are divisible into three
series, viz:

(a) a transverse group, expressive of the action of flexor
muscles.

CHAP. IV]

THIi GENERAL ANATOMY OF GORILLA

101

( b ) a longitudinal group, developed in correlation with adductor
action between the thenar and antithenar eminences.

This survey of the main characters of the Simiidae shews their
close similarity to the Hominidae : at the same time differences as
well as resemblances are indicated, differences chiefly noticeable in
two connections, viz. : with the adaptation of Man to the erect
attitude, and secondly, with the concomitant development of brain-
mass and function. These two principles are closely allied, and
the mode of adaptation of the Primate type to an erect position, and
the characters attendant on the greater cerebral development will
be considered in some of the ensuing chapters.

The following list comprises some of the principal characters
of Gorilla which aid in the elucidation of various human morpho-
logical anomalies.

1. Fronto-maxillary suture in the orbit.

2. Fronto-squamous suture at the pterion.

3. Non-bifid vertebral (cervical) spinous processes.

4. Rudimentary vertebral curvatures.

5. Additional rib-bearing vertebrae.

6. Perforation of the olecranon fossa.

7. Separate ischio-condylar muscle.

8. Variable origin of M. soleus.

9. Disposition of M. interossei of foot.

10. Double M. coraco-brachialis.

11. Lack of operculation of central cerebral lobe.

12. Tendency to subdivision of lobes of liver.

13. The saphenous artery.

14. Dilated laryngeal saccules.

CHAPTER Y.

THE CRANIA OF THE SIMIIDAF. (PRIMATES).

Having completed a general account of the anatomy of
selected types of the Primates, we turn to the cranial characters
of the Simiidae in particular ; and inasmuch as the skull of
Gorilla has already been described, this form will demand less
attention here than the remaining members of the family, viz.
the Gibbons, Orang-utans and Chimpanzees. To the first of
these, the Gibbons, we may now turn, taking as our examples
skulls of animals of the Bornean variety known as Muller’s
Gibbon (Hylobates miilleri), and proceed to consider the points
laid down in the accompanying list.

I. Cranial portion :

General contour.

Sutures.

Ridges.

II. Facial portion :

Orbit: General contour and margins.

Lacrymo-ethmoidal suture.

Lacrymal hamulus.

Infra-orbital suture.

Nasal aperture :

General contour.

Lower margins.

Nasal spine.

Nasal bones.

103

CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES)

Palate : General contour.

Post-palatine spine.

Tuber maxillare.

Palatine sutures.

III. The Temporal Fossa:

Sutures at pterion.

Depth of fossa.

Post-orbital wall.

IV. Base of the skull : Glenoid fossa.

Endoglenoid tubercle.

Margin of foramen magnum.

Styloid process.

V. Dentition: Number of teeth.

Characters of teeth.

VI. Mandible.

CRANIAL CHARACTERS OF HYLOBATES MULLERI.

As is to be expected from the smaller size of the animal, the
skull (Fig. 70) is much less bulky than that of the Gorilla (or
indeed of the other Simiidae) : in length the brain-case (cranium)

Fig. 70. Cranium (with mandible) of Hylobates miilleri : note the absence of
an auditory bulla ; there are spheno-parietal and lacrymo-ethmoidal articulations.
Note also the number of the teeth. (Hose donation II ; Mus. Anat. Cant.)

will be found to measure about 75 mm., whereas in the larger
animals of this family twice that figure would represent the
corresponding dimension.

In size and in general appearance the skull resembles those of
the higher Cercopithecidae rather than those of the Simiidae. It

104 THE CRANIA OF THE SIMIIDAE (PRIMATES) [SECT. A

is to be noticed that the brain-case is proportionately larger in
comparison with the facial skeleton, that the contour is ovoid, that
the sui’face of the cranium is devoid of prominent crests, though
the outline of the area occupied by the temporal muscle is shewn
by an upraised linear ridge. The sutures demand no special
mention. The orbital cavities are remarkably capacious. The
latter feature is associated with the small size of the animal in
accordance with a general law as to the proportions subsisting
between the animal’s absolute bulk and the size of the eyes.
This feature detracts from the appearance of post-orbital lateral
compression of the skull, which would otherwise be marked.

Turning now to other facial characters, it will be seen that
the orbital margins are distinct or trenchant, that the lacrymal
hamulus is vestigial, that the os planum of the ethmoid is not
infrequently divided into anterior and posterior portions, and that
the spheno-maxillary fissure is widely open. The infra-orbital
suture does not persist on the facial aspect. The nasal aperture
has an ovoid form or contour, with margins which are obliterated
interiorly. No nasal spine is seen : the nasal bones are early
conjoined by synostosis, and the compound bone has a somewhat
quadrate contour and is flat, not suggesting the prominence of
the soft parts of the nose. The palate is hypsiloid (U-shaped) in
contour, with a diminutive posterior spine: the tuber maxillare
is also diminutive. In the region of the temporal fossa the
rudimentary character of the alisphenoid (as compared with its
condition in Man) is at once seen : this bone joins the parietal
at the pterion : and the infra-temporal crest is insignificant.

At the base of the skull the shallowness of the glenoid fossa
arrests attention, and it is noticed that no endoglenoid tubercle
is developed as in the Gorilla, though a post-glenoid process is
distinct. The styloid and vaginal processes are not seen.

The dentition provides the normal formula for Catarrhine
Primates. The canines greatly exceed the neighbouring teeth in
size : the molars are tetracuspid and the talon in the lower molars
is not conspicuous.

The mandible is characterised by the shortness of the ascending
ramus, by the projection of the angle and by the absence of genial
tubercles.

CHAP. v] THE CRANIA OF THE SIMIIDAE (PRIMATES)

105

CRANIAL CHARACTERS OF SIMIA SATYR US.

Next in order will be taken the Orang-utan (Simia satyrus).
The researches of Selenka of Munich led him to distinguish some
seventeen different varieties or local races of Orang-utans : as the
differences by which these races are distinguished affect only
secondarily the skull, it will not be necessary to specify the
particular variety described and indeed in the absence of the soft
parts this would be a difficult if not an impossible problem.

Taking as our example, then, a young individual on the verge
of maturity (cf. Fig. 71), we remark at once the great increase in
size upon that of the Hylobates skulls. The proportions too of
face and cranium are different, the facial part having gained in
bulk ; to this gain a notable contribution is made by the mandible.

In proportions, the cranial part of the skull is, when contrasted
with the facial part, less elongated than in Hylobates, and presents
the nearest approach to bra-
chycephalic proportions (cf.

Chapter XI ) met with among
the Simiidae. The cranial su-
tures early become simplified
and are closed by synostosis.

Traces of the division of the
parietal bone into upper and
lower halves are stated by
Ranke to be very frequent
(the trace consisting in a
remnant of the dividing suture
persistent at its starting point
from the coronal suture).

Rapidly converging from
the external angular processes
of the frontal bone, the tem-
poral ridges vary in their
ultimate conformation, the
sexual element being of im-

Fig. 71. Cranium (with mandible) of
an Orang-utan (Simiidae) ; note the absolute
obliteration of nasal prominence, the absence
of an auditory bulla, the presence of a
spheno-parietal articulation, and the num-
ber of the teeth. The lacrymal and ethmoid
bones join on the inner orbital wall with
separation of the frontal bone and maxilla.

portance. For in the female

Orang-utan the ridges may remain separated throughout their

106 THE CRANIA OF THE SIMIIDAE (PRIMATES) [SECT. A

course, or may barely come into contact with one another, whereas
in the male animal, not only may the ridges meet, but they may
rise in the form of a crest measuring as much as 10 mm. in height.
Posteriorly, the temporal ridges vary too, in male examples
meeting the superior nuchal line, and forming a lambdoid crest
not seen in female skulls.

The orbits have an elliptical contour, and the brow ridges are
not (as in the African Simiidae) continuous from side to side of
the forehead. The orbital margins are distinct; the lacrymal
hamulus vestigial, but there is an elongated lacrymo-ethmoidal
suture, for the os planum of the ethmoid though of small vertical
extent is somewhat broader anteriorly than elsewhere.

The spheno-maxillary fissure is a mere cleft of small dimen-
sions, the post-orbital wall being in consequence almost complete.
The infra-orbital suture rarely persists long on the facial surface.
The nasal aperture is pyriform with upwardly directed apex :
interiorly the nasal margins are quite lost, and no nasal spine
is seen. The nasal bones are more reduced in size than in any
other Primate mammal; usually the conjoined bones form a mere
elongated splint, and not infrequently no distinct nasal bones are
seen at all : sometimes a small ossicle at the upper margin of the
nasal aperture is all that remains; the nasal processes of the
maxillae then join each other between the orbits.

The palate is elongated and hypsiloid: the tuber maxillare
is variable in development, as is also the post-palatine spine.

The temporal fossa is deep, owing to the bowing outwards of
the zygomatic arch and the channelling of the alisphenoid. The
latter bone touches the parietal, and thus the Orang-utan agrees
with Hylobates and Man and many lower Primates, but differs
from the African Simiidae and most of the Catarrhine monkeys :
the variations in human skulls in this respect will be described in
a subsequent chapter.

The infra-temporal crest is insignificant. At the base of the
skull the shallowness of the glenoid fossa is to be remarked. The
endoglenoid process or tubercle is small, as is the styloid process,
which is often absent. The vaginal process is also absent.
Anomalies about the margin of the foramen magnum are rare.

The teeth provide the normal formula, but in males accessory

CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES)

107

molar teeth are extremely common. The great length of the
roots of all the teeth is noticed by Tomes ( Dental Anatomy) as
peculiar: so also the curious crenation of the enamel (which, though
a feature of the developing tooth, persists in the crowns of the
molars of the Orang-utan) is remarkable. The principal points
of importance in the mandible are its very massive character in
proportion to the rest of the skull ; the ascending ramus, which
is higher than in Hylobates : and which bears a shallow sigmoid
notch.

CRANIAL CHARACTERS OF ANTHROPOPITHECUS NIGER.

There remain to be enumerated the cranial characters of the
Chimpanzee (Anthropopithecus niger). It may be pointed out
that this ape and the Gorilla agree in several important respects
wherein they both differ from the Orang-utan. This general
statement applies to the skull as well as to other anatomical
structures.

Taking as our example a young, but nearly mature, in-
dividual (Fig. 72), we notice that,

viewed from above, the skull of the
Chimpanzee is more ovoid in form
than than that of the Orang-utan.
The facial skeleton is rather smaller
in proportion to the cranial part than
in either the Orang-utan or the
Gorilla, and here in the Chimpanzee
skull (especially in infancy, cf. Fig.
73) suggests the proportions of the
human skull, though it is still far
from realizing them.

Of the cranial sutures, the sagittal
may be extremely complicated and
tortuous before it becomes closed ; on

Fig. 72. Cranium with man-
dible of a Chimpanzee (Simiidae):
note the absolute obliteration of
nasal prominence, the lack of an
auditory bulla, the presence of
fronto-squamous and fronto-max-
illary (orbital) articulations : note
further the number of the teeth.

the other hand, the straight outline of the suture dividing the
parietal bone from the squamous portion of the temporal bone is
to be noted.

Bony crests occur on the surface of the cranium, but are

108

THE CRANIA OF THE SIMIIDAE (PRIMATES) [SECT. A

comparable rather to those of the Orang-utan than those of the
Gorilla. For it is the exception rather than the rule for the
temporal ridges to form a median sagittal crest : they commonly
run in close approximation along the sagittal suture, diverging
thence with the formation of lateral lambdoid crests.

Fig. 73. Crania, with mandibles, of (A), young Gorilla, and (B) young Chim-
panzee (Simiidae). The first permanent tooth (m) (the first molar) has just been
fully acquired in each case, and comparisons can thus be drawn between examples at
corresponding stages in development. Note the greater nasal prominence in the
Gorilla ; and the fronto-squamous and the fronto-maxillary (orbital) articulations in
both specimens.

The contour of the orbit is less definitely elliptical than in the
Orang-utan, and herein the Chimpanzee and Gorilla resemble one
another; similar agreement between the two African apes is seen
in the prominence of the external angular processes of the frontal
bone, in the continuity of the supra-orbital ridge between these
two processes and across the inter-orbital space, in the bevelling of
the external orbital margin, and in the shortness of the lacrymo-
ethmoidal suture. The lacrymal hamulus is vestigial, and the
spheno-maxillary fissure reduced to a narrow cleft.

The nasal aperture is pyriform, with the truncated apex above ;
the lower margins of the aperture are obliterated, and no nasal
spine is seen. The nasal bones are often conjoined at an early
epoch, and their fiat expanse is not relieved by the very remark-
able median l'idge so characteristic of these bones in the Gorilla.
The nasal bones preserve a more uniform breadth from above
downwards than in the Gorilla, and do not extend so far below the

’D

109

CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES)

level of the lower orbital margins as in the latter animal.
The palate has the characteristic simian hypsiloicl contour, and
the post-palatine spine is small, as is also the tuber maxillare.
Great irregularity of the arrangement of the palatine sutures is
frequent.

The temporal fossa owes its depth largely to the channelling of
the alisphenoid, which commonly articulates with the frontal and
squamosal above, being separated by these two bones, which join
at the pterion. The infra-temporal crest is often represented by
a single spinous process.

The base of the skull shews the foramen magnum in the
position characteristic of Simiidae, i.e. much nearer the occipital
end of the skull than in the Hominidae. The glenoid fossa is
shallow, with a moderately developed endo-glenoid tubercle, and
small post-glenoid process. As in the Gorilla, an Eustachian
spinous process is common, but the styloid and vaginal processes
are absent. The tympanic bone, as in the other Simiidae, is long
and semi-cylindrical in form. The occipital condyles are small and
variations in the conformation of the margins of the foramen
magnum are rare.

The dentition presents the normal Catarrhine formula : the
canine teeth, except in old males, do not so far surpass the other
teeth in bulk, as in Simia and Gorilla. In the reduced size of
the third upper molar tooth, and in the small size of the cusps of
the molar series, anticipations of the human cqndition are met Avith.
Slight but distinct crenation of the crowns of the molar teeth
frequently occurs.

In the development of frontal air-sinuses, and of similar air-
cavities in the ethmoid bone, with dilation of the nasal duct, where
this is in relation with the maxillary antrum, the Chimpanzee and
Gorilla agree, and approximate to the human condition (cf. Keith,
Proc. Anat. Soc., 1902), while they differ herein from the Orang-
utan and Gibbon.

In concluding these brief descriptions of the external characters
of the skulls of Simiidae, it is convenient to present the main
points of diagnosis of the several genera in a tabular form as
follows :

110

THE CRANIA OF THE SIMIIDAE (PRIMATES) [SECT. A

Distinctive features of the skulls of Simiidae.

I. Hylobates (Gibbon).

Its small size differentiates it from those of other Simiidae.
The skulls of Cercopithecidae of similar size are distinguished
by their relatively smaller capacity and by the nasal bones
(which are longer than in Hylobates). The molar teeth do
not possess the two transverse ridges crossing the croAvn which
are so characteristic of the teeth of the lower Anthropoidea.

II. Simia (Orang-utan).

Distinguished by its absolute size from the skull of Hylo-
bates.

Distinctions from Chimpanzee and Gorilla:

(a) The supra-orbital ridge for each orbit is distinct and
the two ridges are not continuous across the forehead.

(b) The nasal bones are reduced to mere splints.

( d ) The mandible is, relatively to the rest of the skull, of
large dimensions.

III. Anthropopithecus (Chimpanzee).

Distinguished by its absolute size from the skull of Hylo-
bates.

Distinctions from Simia are as indicated above.

(a) The supra-orbital ridges are continuous across the
forehead.

(b) The nasal bones though flat and short are laminar
and not splint-like.

(cl) The mandible is relatively smaller.

The following are the distinctions between the crania of
Chimpanzee and Gorilla.

(a) The skull of the Chimpanzee is smaller, the cranial
part is relatively larger, and not characterised by such large
ridges as the skull of Gorilla.

CHAP, v] THE CRANTA OF THE SIMIIDAE (PRIMATES) 111

( b ') The nasal bones are shorter (not extending far below
the level of the inferior orbital margins), and their outer
margins are more nearly parallel to one another than in
Gorilla.

(o') The nasal aperture tends to be pyriform in contour.

(, d ') The molar teeth are smaller and bear less prominent
crowns.

IV. Gorilla.

The skull is distinguished by its actual size from that of
Hylobates.

The following are the features distinguishing the skull of
the Gorilla from that of the Orang-utan.

(a) As in Anthropopithecus, the supra-orbital ridges are
continuous across the forehead.

(b) The nasal bones are splayed and wide, though flat.

( d ) The cranial ridges are very large.

And the features which differentiate the skulls of the
Gorilla and the Chimpanzee are as follows :

(a) The whole skull of the Gorilla is larger : the facial
part is relatively larger : the cranial ridges are very large and
prominent.

( b ') The nasal bones are long, and wide at their inferior
margins : they thus end at a level well below that of the in-
ferior orbital margins.

( c ) The nasal aperture is ovate rather than pyriform.

(d') The molar teeth bear very large cusps and are larger
than in the Chimpanzee.

From external features we pass to those revealed when the
skull is sectionized in the median sagittal plane, and the exami-
nation of such sections is to be particularly recommended as
leading to important conclusions on the essential differences
between the skulls of Simiidae and Hominidae.

112

THE CRANIA OF THE SIM1IDAE (PRIMATES) [SECT. A

If the section of a skull of one of the Siroiidae thus prepared,
be examined (a suitable example is that of a Gorilla, Fig. 4, with
which compare Fig. 74, the tracing from an Orang-utan, skull), the
following features will at once be noticed in comparison with the
corresponding section of a human skull.

Fig. 74. Tracing from the cranium of an Orang-utan (Simiidae) bisected
in the median sagittal plane. (Mus. Zool. Cant.)

The relatively great development of the facial skeleton is
as evident as when the skull is examined externally. The
characteristic prognathism of the ape is very marked. The con-
stituent elements of the nasal septum correspond individually to
those seen in a similar section of a human skull, the differences
consisting in the details of contour and conformation. In relation
with the greater size of the maxilla the system of air-spaces is

CHAP. V] THE CRANIA OF THE SIM1IDAE (PRIMATES) 113

more extensive in the simian skull ; this is best seen when the
nasal septum is removed (or when that section which does not
include the septum is examined). The ape will be found to
possess extensive sinuses in the sphenoid, ethmoid and maxillary
bones, but not in the frontal bone, a point wherein the Orang-utan
differs from the African Simiidae (Chimpanzee and Gorilla), which
in this respect are more closely allied to man than is the former
ape. In the corresponding preparation of the skull of a Gorilla
a large bullous dilatation of the nasal duct will be seen projecting
into the maxillary antrum, along the roof of which the infra-orbital
nerve runs in a bony canal. In the Orang-utan, the part of the
frontal which is excavated by the frontal sinuses in the other
apes, is a solid mass of bone which may attain a thickness
of nearly 20 mm.: seen in section, this thickness is reduced to
about a quarter of this amount at the coronal suture, and the
latter dimension is retained to the region of the lambdoid suture,
where it is increased by the ridge which crosses the skull in
a position corresponding to the lambdoid suture in man.

In contrast to the human skull, the bones of the cranial vault
thus form an arch of much less bold proportions, and this is
perhaps most noticeable at the occipital end of the skull, which
gives the impression of having been arrested in development,
leaving the occipital arc but slightly curved, and the foramen
magnum consequently midway between the posterior and the
inferior aspects of the skull.

The endocranial surface bears faint impressions due to the
cerebral convolutions1; the floccular fossa is not present, and its
absence constitutes a difference between the simian and cerco-
pithecoid skull. The superior petrosal sinus may be almost
completely roofed in by bone, a bony bridge may be formed over
the Gasserian ganglion, and the posterior and anterior clinoid
processes may be connected by bone : the orbital roof will be seen
to rise from the cribriform fossa much more steeply than in the
human skull. Continuing the inspection of the sectionized surface,
the series of bones forming the base of the skull is next met with :
and the basi-occipital, the sphenoid, and ethmoid elements are
easily recognisable. The crista galli does not exist in the Simiidae

1 Cf. Schwalbe, L’ Anthropologic, 1904.

D. M.

114

THE CRANIA OF THE SIMIIDAE (PRIMATES) [SECT. A

as a rule, and certainly is not seen here. Anteriorly, the nasal
spine of the frontal hone will be seen to be rudimentary, and in
the Orang-utan the superior maxilla may come into the section in
place of the nasal bone, as a consequence of the diminutive size,
or extent, or of the absence of the latter element. But it is to the
arrangement of the ethmoid, sphenoid and basi-occipital elements
of the cranial base that special attention must be given.

It will be seen (cf. Figs. 4 and 74) that anteriorly the line of
section of the upper margin of the ethmoid forms a plateau, nearly
horizontal in direction, and that passing backwards from this, the
line of the upper margin of the sphenoid is (with the exception of a
hillock representing the section of that portion of the presphenoid
which lies between the two orbito-sphenoids) practically continuous
with the clivus, the line passing almost directly to the margin of
the foramen magnum without interruption. The point to which
attention is drawn is that this line forms with that of the upper
margin of the ethmoid an angle salient endocranially, open below,
and moreover widely open, approximating to the value of 180°, or
two right angles. A glance at the human skull (cf. Fig. 75) shews
the inclination of the two lines to be represented by a very much
smaller angle. There are various ways of measuring this angle,
and these will be described in detail in another connection, but
for the moment it will suffice to call attention to the general
appearance. The conclusion is, that in the simian skull the
basal elements are arranged nearly in line, but that in the human
skull this line is inflected ; this inflection constitutes an important
peculiarity of the human skull.

If now we pass beyond the limits of this group of animals,
and turn our attention first to the lower Primates, and secondly
to other mammals, we shall find that the straightness of the series
of basal elements becomes more marked as we descend the series,
and that long before we leave the Primates the straightness is
interrupted, and that in the following way.

If we suppose the central part of the series of bones, viz. the
sphenoid and the basi-occipital (B. Pr., Fig. 75), to be the more
fixed portion of the base, then we can describe the condition
obtaining in the human skull as one in which the ethmoidal
element (Pr. N., Fig. 75) is bent, of inflected, strongly downwards

115

CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES)

from the anterior end of this fixed portion. And proceeding
to the simian skull, the appearance is such that the ethmoidal
element is bent downwards to a smaller degree, so much less in
fact, that it is almost in line with the fixed portion as just defined.
Lastly, when we examine the skull of a lowlier primate form such
as Mycetes (Cebidae), the condition is such that the ethmoidal
line is so to speak reflected, or bent, not downwards, but upwards
(as in the Carnivora; cf. Figs. 75 and 77) with regard to the more
fixed element.

We may now turn our attention to the region of the foramen
magnum. This was seen to be placed in the simian skull rather
at the junction of the posterior and inferior aspects of the cranium,
than frankly on the inferior aspect as in Man.

A line (Op. B., Fig. 75) drawn from the anterior to the posterior
median point on the margin of this foramen represents what is
described as the “ plane of the foramen magnum ” (Cleland called
it the “ posterior base of the skull ” but the former name may be
retained for the moment) ; the line representing this plane (and
therefore the plane itself), will be found to be inclined to the

Fig. 75. Cranium of an aboriginal native of Australia (Hominidae) bisected in
the median sagittal plane. N. Pr. represents the anterior or ethmoidal portion of
the cranial base ; Pr. B. is the middle or basi-occipito-sphenoidal portion ; B. Op.
represents the plane of the foramen magnum.

spheno-basilar or “fixed” portion of the base (B. Pr., Fig. 75), in
such a way that the angle between the two is salient downwards
and backwards (cf. Figs. 4 and 74): moreover in the Simiidae
the angle is a large one (varying from about 120° to 140°).
Turning to the human skull, we find that the mean value is
rather greater (the variations ranging from about 137° to 157°).

8—2

116

THE CRANIA OF THE SIMI1DAE (PRIMATES) [SECT. A

But if now we turn again to the lower Anthropoidea, to the lowlier
primate forms and mammalian orders, we find that the angle is
very much smaller, and has much more nearly the value of a right
angle ; this is very evident in the Cynocephalous monkeys, or in
Carnivora (cf. Figs. 75, 76, and 77).

We thus arrive at the conclusion that in the evolution of the

Fig. 70. Cranium of a Baboon (Cercopithecidae) bisected in the median sagittal
plane. The lines represent the plane of the foramen magnum, and the cranio-facial
axis respectively.

Fic 77 Cranium of a Dog (Carnivora, Canidae) bisected in the median
sagittal plane : to shew the two sections into which the cranio-facial axis has been
conventionally divided. The line Op. B. represents the foramen magnum , B. Pr.
the “middle base,” and Pr. N. the “anterior base.

CHAP. V] THE CRANIA OF THE S1MIIDAE (PRIMATES) 117

form of the skull important changes have taken place in the
relations of the anterior and posterior basal portions respectively,
to the intermediate, centrally-placed part. And that if the latter
be regarded as comparatively fixed, the anterior or ethmoidal part
at one end, and the posterior or foraminal portion at the other,
vary from animal to animal in such a way as to enable one to
compare them to levers fixed at each end of a bar which serves
as a fulcrum to both. Further, that in the lowliest forms of
the Eutherian skull the conditions may be represented diagram -
matically by supposing each lever to be raised above the (more
or less) horizontally placed middle portion, thus (Fig. 78, with
which compare Fig. 77):

\ /

B Pr

Hg. 78. This and the three succeeding figures represent the component parts
of the cranial axis in the several stages which mark the path of evolution of the
human type (Fig. 81) from the generalised mammalian type (Fig. 78, with which
cf. Fig. 77). In the latter (Fig. 78) the line B. Pr. represents the comparatively
stable middle portion, extending from the basion (cf. Chapter x.) to the prosphenion,
or most anterior point of the sphenoid bone. B. Op. represents the plane of the
foramen magnum; and Pr. N. , the line from the prosphenion to the nasion,
represents conventionally the plane of the cribriform fossa. These indications
apply to the whole series of figures (78 — 81 inclusive).

We have seen that in the simian skull, both levers have been
depressed to a considerable extent, the anterior, ethmoidal one,
more than the posterior, foraminal one ; so that the diagram for
the simian type of skull is as represented in Fig. 79 (with which
compare Fig. 74) :

118

THE CRANIA OF THE SIMIIDAE (PRIMATES)

[SECT. A

or, since the anterior element is now the more nearly horizontal
one, thus (Fig. 80) :

Pig. 80.

while finally, in Man, the condition incipient in the Simiidae has
been brought to a further stage, and the appropriate diagram is as
shewn in Fig. 81.

It is therefore to be noticed (a), that the human skull is
characterized by the degree of flexion of these anterior and
posterior elements upon that part of the base which lies between
them ; (b), that the simian skull indicates this change in an
incipient stage, and is thus anticipatory of the human skull1.

Such then are the chief features of interest in the sectionized
skull, and their enumeration and description may be not unfitly

1 In the foregoing account an attempt has been made to give a general descrip-
tion only of the essential features of the cranial base, and of the changes which
are seen in its evolution. No reference has been therefore made to exact angular
measurements ; nor to the exact details of procedure that should be followed in
drawing the lines by which such angles are included. Nor has special reference
been made to the cranio-facial axis as such : this would have necessitated reference
to the nasal bones with consequent complication of the description.

CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES) 119

followed by an indication of their significance. Assuming that
the conformation of the cranium is largely expressive of the
conformation and development of the encephalon which it encloses,
it is to the latter that an appeal must be made in elucidating the
differences in the several crania investigated. Nor will the appeal
be made in vain. For in the lowly Mammal and lowly Primate,
the encephalon is still, in the great majority of cases, relatively
small, and the cerebral hemispheres have not assumed the
exuberance of growth which is a characteristic of the higher
forms. When this tendency to cerebral growth has been initiated,
it is found that the inferior aspect of the cerebrum, the base of
the brain, the floor of the third ventricle and the allied and
adjacent structures, remain comparatively passive, while the cere-
bral hemispheres tend to expand in all directions, anteriorly,
posteriorly, and laterally, upwards and downwards.

A glance at the series of diagrams of the sections of skulls will
shew how such expansion implies pressure in those directions;
acting anteriorly, this will force the cribriform fossa first forwards
and ultimately downwards, the transition being capable of repre-
sentation by the movement of the anterior lever of our diagram
(Pr. N., Fig. 78, p. 117), the active force being indeed the intrinsic
cerebral growth. Posteriorly, similar expansion drives backwards
and then downwards the occipital wall of the cranium, and with
it the foramen magnum in a similar way, capable too of similar
representation (see Figs. 78 to 81 inch, pp. 117 and 118).

Expansion upwards produces the bold vaulting of the cranial
arc, and in all these respects it is to the human cranium that we
are led by the successive stages assumed in the lower and higher
quadrupedal monkeys respectively, and in the Simiidae themselves.
In Man the effect is at a maximum, the lower Primates merely
suggesting the development that is to be.

A few remarks may now be made in conclusion of this part
of our subject. Viewed in this light, we see how the study of
skulls of various mammals gives us guidance as to their cerebral
or encephalic conformation. Hence the study of the osteology
of living forms is of paramount importance with respect to the
study of extinct forms, of which only the skeletal parts remain.
Secondly, there remains a word of warning as to the “fixity” of

120

THE CRANIA OF THE SIMI1DAE (PRIMATES) [SECT. A

the central part of the base of the skull. This fixity is not
absolute, for even this central portion participates in the flexion
consequent on the pressure of the rapidly enlarging brain. But
for the purposes of description, and for the general realization
of the circumstances attendant on the evolution of the character-
istic form in the Simiidae and Man, it is justifiable to neglect this
secondary change. Finally, the impression left on one’s mind by
the study of the cranial osteology of these large apes (and the
same remark applies to other departments of their anatomical
structure), is that they are evidently examples of highly specialised
Primates. So evident indeed is this, that a table can be drawn
up to shew that there are not lacking features in which the
Simiidae even surpass the Hominidae in point of morphological
specialization. And while it is inappropriate to enter further
upon this subject here, the table may be of interest as illustrative
of the point in question.

Table.

In
will be
and to
genert
as :

(1)

(2)

comparison with the crania of Simiidae, the human skull
seen to be more highly specialised
have departed further from the
ilised type in point of such features

Inflection of the basis cranii.
Forward position of the foramen
magnum (cf. Fig. 82).

(3) Diminished proportions of the

maxilla.

(4) Early and complete fusion of

the premaxilla and maxilla.

(5) Large ascending mandibular

ramus, and coronoid process
with a deep sigmoid notch
behind it.

(6) Prominence of the chin.

Forarr-jet}

Fig. 82. Basis cranii of an
Orang-utan, shewing the posi-
tion of the foramen magnum,
far back in contrast with its
position in the human skull.
Fig. 75 should also be compared
with Fig. 77, when the same
contrast will be observed.

On the other hand, the following features may be claimed

121

CHAP. V] THE CRANIA OF THE SIMIIDAE (PRIMATES)

as shewing that the human skull is therein more generalized
and primitive than those of the Simiidae.

(1) Lack of bony ridges.

(2) Large nasal bones.

(3) Wide spheno-maxillary fissure.

(4) Articulation of parietal and sphenoid bones at the

pterion1.

(5) Articulation of lacrymal and ethmoidal bones in the

orbit1.

(6) Uniformity in the size of the teeth.

It should be understood however, that these lists are not
exhaustive;

1 The contrast is in this instance with the African Simiidae only.

CHAPTER VI.

THE DENTAL SYSTEM OF THE PRIMATES.

In enumerating the methods of investigation which have
proved of assistance in elucidating the ancestral history of existing
animal forms, reference was made to the study of fossil remains.
From the nature of their constitution, the teeth are particularly
apt to be preserved in the fossil condition, and for this reason the
study of the characters of teeth claims special attention in
connection with investigations undertaken with the object cited
above. For the same reason it is appropriate to review, even
though very briefly, the normal features of the teeth in the more
representative members of the Primates, and besides the palaeon-
tological interest of this study, another claim is presented, in view
of the inferences that may be drawn from the direct morphological
comparison of the several animals subjected to such an enquiry.
The following notes will therefore deal in succession with the
main dental characters of representatives of the Lcmuridae, of the
Cebidae, Cercopithecidae, Simiidae, and Hominidae ; of these the
canine and post-canine teeth will first be considered, and subse-
quently the characters of the incisor teeth will be briefly indicated1,
the permanent and not the transitory teeth being in all cases
considered.

A. THE CANINE AND POST-CANINE TEETH.

LEMUROIDEA. Lemuridae. Lemur varius (cf. Fig. 18).

Dental formula : i, f ; c, ^ ; pm, § ; m, § ;

The upper teeth : Fig. 83. The canine tooth is remarkably large with a

1 The following figures (Nos. 83 to 107 inclusive) represent the several teeth in
their natural proportions, without reduction.

123

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

trenchant posterior margin : its socket is separated by a distinct interval from
the lateral incisor in front of it (diastema), and from the premolar behind it.
The premolar teeth are three in number, and increase in size from before
backwards ; the first is very small with a relatively immense, sharp, central
cusp, supplemented by minute anterior and posterior cusps. The second
premolar tooth is larger, the central cusp still immense, and an internal cusp
is suggested on the surface of the cingulum (a band which surrounds the base
of the tooth crown) ; in the third premolar tooth this internal cusp is still
more marked. The molar teeth are tricuspid (or tritubercular, cf. p. 146) and
the cingulum is distinct, forming internally a prominent band which skirts

Figs. 83

89 90

Fig. 83. Right upper canine and post-canine teeth of a Lemur. (No. 4, Mus.
Zool. Cant.)

Fig. 84. Left lower canine and post-canine teeth of a Lemur. (No. 4, Mus.
Zool. Cant.)

Fig. 85. Right upper canine and post-canine teeth of Cebus capucinus. (No.
1093, Mus. Zool. Cant.)

Fig. 86. Left lower canine and post-canine teeth of Cebus capucinus. (No.
1093, Mus. Zool. Cant.)

Fig. 87. Right upper canine and post-canine teeth of a Macacus monkey.
(Cercopithecidae.)

Fig. 88. Left lower canine and post-canine teeth of a Macacus monkey.
(Cercopithecidae.)

Fig. 89. Right upper canine and post-canine teeth of Hylobates mulleri.
(W.L.H.D. priv. coll.)

Fig. 90. Left lower canine and post-canine teeth of Hylobates mulleri.
(W.L.H.D. priv. coll.)

124

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

the inner of the three cusps ; the other two cusps are external (cf. Fig. 83).
The third and last molar tooth is much smaller than the second, and as this
is smaller than the first, the series diminishes backwards in size. In the
mandible (Fig. 84) the formula (?;. supra) requires some elucidation, for the
canine tooth (judged by the formula) is apparently incisor-like in form,
and it is also procumbent, or directed horizontally forwards like the definite
incisor teeth (v. infra , p. 133). Moreover, the first premolar tooth resembles
a canine tooth. The question of the identification of these teeth is still in
doubt ; Forsyth-Major ( Geological Magazine , 1900) has adopted the view
which regards the canine-like tooth as the genuine canine, and the outer
incisor-like tooth as an incisor, thus providing the mandible with a dental
formula i, 3; c, 1 ; pm, 2 ; m, 3 ; different, that is, from the maxillary
formula i, 2 ; c, 1 ; pm, 3 ; m, 3. But it is to be noticed that against this view
may be urged the fact that the canine-like premolar tooth although admittedly
canine in form, yet closes in the bite posteriorly, and not anteriorly, to the
upper undoubted canine tooth. Now this posterior position of a lower canine
tooth is a phenomenon of extreme rarity, and though
Forsyth-Major defends his position by appealing to the
progressive shortening of the mandible, which no doubt
has occurred, still in view of the mutability of dental
forms, it seems more consistent to adopt the opposite
view of regarding the canine tooth of the mandible as
incisiform, and the first premolar tooth as caniniform1.

All the mandibular teeth are flattened from side
to side, the premolars bear one relatively immense
cusp and three minute subsidiary cusps, cf. Fig. 91,
and the middle premolar tooth is the smallest of the
three. The molar teeth are quadricuspid, the two
cusps being external and larger than the two remaining
and internally situated cusps, and these teeth diminish
in size backwards. Such diminution backwards suggests
that the jaws are undergoing a process of reduction in
length which is in operation at the posterior extremity. In addition to
this, Forsyth-Major has pointed out that retraction of the mandible as a
whole has occurred.

Nycticebus (Lemuridae). In this form (as in the slender Loris) the molar
teeth of the upper jaw are four-cusped, the cusps being arranged in two pairs,
with an oblique ridge joining the antero-internal to the postero-external cusp.
This arrangement is met with rarely among the Cebidae, entirely lost in the
Cercopithecidae, but reappears in the Simiidae and Hominidae, of the dentition
of which families it is a marked feature.

Fig. 91. Enlarged
view of the lower pre-
molar tooth of a Le-
mur (W.L.H.D.).

1 Flower and Lydekker, Mammals, p. 683, suggest that the canine tooth is
absent altogether.

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

125

ANTHROPOIDEA. Cebidae. Cebos capucinus.

Dental formula of the family : i, f ; c, ^ ; pm, § ; m, § .

The upper teeth : the canine teeth (Fig. 85) are relatively enormous in size,
especially in the male sex (cf. Fig. 21) ; the post-canine teeth present a feature
of marked contrast with the corresponding teeth of the Lemuridae, inasmuch
as the crowns appear much reduced in the antero-posterior direction (this is
even more distinct when the lower series are compared, cf. Figs 84 and 86).
A diastema is present. The premolar teeth are three in number and bicuspid,
with anterior and posterior cusps : in size they diminish progressively back-
wards. Of the three molar teeth, the first is the largest and the diminution
in size backwards is very rapid, the last tooth being minute. The molar teeth
bear four cusps, two outer and two inner, and in the species under considera-
tion (C. capueinus) no connecting ridges are seen. In some forms the antero-
internal and postero-external cusps may be connected by an oblique ridge
(cf. Fig. 118).

The lower canine teeth correspond to the upper teeth in size, and close
anteriorly to these as in the great majority of Eutheria. The first of the
three premolar teeth is pyramidal and suggests a transition from the canine
form to the bicuspid premolar form : it bears one predominant cusp and a
second smaller cusp, and is distinctly larger than the two remaining premolar
teeth, which are bicuspid with external and internal cusps, and sub-equal in
size. The three molar teeth diminish rapidly in bulk backwards, the last being
clearly degenerate, and this degeneracy in the third molar teeth of the otherwise
comparatively primitive Cebidae must be insisted on. Such reduction is again
met with in the Simiidae and Hominidae, but must not be regarded as confined
to these higher families of the Primates. The molar teeth bear three distinct
cusps, two external and one antero-internal, the postero-internal cusp being
quite indistinct, especially in the last tooth. The three better marked cusps
are connected by rather indistinct ridges1.

ANTHROPOIDEA. Cercopithecidae. Macacus rhesus.

Dental formula : i, f ; c, j ; pm, f ; m, §. (Figs. 87 and 88.)

The canine teeth, which may in male specimens attain very great
dimensions (cf. Fig. 28) are preceded in the upper jaw by a distinct diastema.
The upper premolar teeth (two in number) are bicuspid but are implanted by
three roots. (In the types hitherto considered, the number of roots of the
premolar teeth has varied ; in some teeth the root is single and in others even

1 The indistinctness of the postero-internal cusp is important. As will be shewn
later (in Chapter xvi) the indistinctness of a particular cusp has been appealed to in
support of a particular view concerning the fossil Pithecanthropus erectus. The
point therein raised is that in the lower Primates, the reduction in cusps affects the
postero-external before it modifies the postero-internal cusp (while in the Hominidae
the postero-internal is the first of the two to shew signs of reduction). But the
incompleteness of this generalization is clearly shewn by the foregoing observation.

126

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

in the same jaw, three roots being present.) As in Cebusthe premolar crowns
shew signs of antero-posterior flattening, the outer cusp of the first tooth is
much larger than the inner and the two teeth are nearly equal in size. The
upper molars bear four cusps, two external (buccal) and two internal (lingual)
united in pairs by transverse ridges, and implanted by three roots. The
second tooth is the largest, the first and third being nearly equal in size,
though the latter may be in some instances reduced. There is no distinct indi-
cation of reduction of cusps in the third molar tooth. The lower canine tooth
corresponds in dimensions to the upper, and the first lower premolar tooth is
caniniform, the lingual (internal) cusp being quite overshadowod by the
hypertrophied external cusp. As in all the lower post-canine teeth the roots
arc two in number, and the same teeth preserve the lemurine feature of
lateral compression, though this is only marked in the first premolar tooth.

The three molar teeth increase in size progressively backwards : their
crowns bear four cusps united in pairs by transverse ridges, and in the last
teeth the posterior projection known as the “ talon ” is well developed and
bears one or even two subsidiary cusps.

As will be explained later (p. 149) stress has been laid on the presence of
the transverse ridges upon the crowns of the molar teeth (whether upper or
lower) of the Oercopitheeidae, to the exclusion of an oblique ridge.

ANTHllOPOIDEA. Simiidae. Hylobates mulleri : a Gibbon

from Borneo.

Dental formula : i, f ; c, ; pm, f ; m, §. (Figs. 89 and 90.)

The upper teeth. The canine teeth are very long and slender (cf.
Fig. 70) and preceded by the diastema. The premolars are bicuspid
with three roots, and the first of the two is caniniform in so far as
the outer cusp is much larger than the inner, the latter being very
obviously a derivative of the cingulum. In the second prcmolar tooth
this disparity is less distinct, and this tooth is rather larger than the first.
The three molar teeth decrease in size progressively backwards. Like the
premolar teeth, they are implanted by three roots, two external and one in-
ternal, and their crowns bear four cusps, two external (lingual) and two
internal (buccal) in position. It is important to note that these cusps lack
the transverse connecting ridges which are so characteristic of Cercopithecidae,
but which are here replaced by an oblique ridge uniting the antero-internal
with the postero-external cusp. The significance of this will be discussed in
another connection (cf. p. 149). The third molar tooth bears signs of degene-
ration, two posterior (lingual and labial) cusps and the oblique ridge being in
some cases vestigial and indistinct. The lower teeth (Fig. 90) situated behind
the canine tooth are implanted by two roots each, these roots being anterior
and posterior in position as is the general rule in the Primates. The lower
and upper canine teeth correspond in development, and it is noteworthy that
traces of lateral compression are perceptible in these teeth.

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

127

The post-canine teeth still present signs of the same lateral compression
though this feature is less conspicuous than in the Lemurs and even the Cerco-
pithecidae ; for a process of antero-posterior reduction is now being initiated,
with the result of rendering the crowns of the teeth equilateral in pro-
portions.

The first of the two premolar teeth (cf. Fig. 89) bears one very large
(lingual) and a much smaller (labial) cusp ; it is larger than the succeeding
tooth, the crown of which is furnished with two small cusps, behind which an
undoubted though minute talon is seen.

The lower molar teeth vary in different specimens, but the second tooth
would seem to be the largest, next to this the first, though this and the third
are in some cases equal in bulk. The crowns bear four or five cusps ; viz. an
anterior pair (external and internal) which may be connected by a transverse
ridge1 ; and a posterior pair not so connected, and between which a fifth
minute cusp may be seen : the last-mentioned cusp may be regarded as
representing in a reduced form the bicuspid talon, so conspicuous in the
Cercopithecidae ( q.v . p. 126). Finally, it should be noted that in the reduc-
tion affecting these cusps, the inner (lingual) posterior cusp is involved to a
greater extent than the outer. This affects a point of controversy to which
attention has already (p. 125, footnote) been drawn.

ANTHROPOIDEA. Simiidae. Simia satyros (Orang-utan).

Dental formula : cf. Hylobates. (Figs. 92 and 93.)

In correspondence with the greater absolute bulk of these animals the
teeth of the larger Simiidae are larger than any others hitherto considered.
As in most of the Anthropoidea, the sexual factor has an important influence
upon the dentition and particularly upon the dimensions of the canine teeth.
The transitory dentition is found in all the Primates so far as they are
known ; in the case of the higher members of this Order (cf. Figs. 32 and 73)
a very close agreement with the phenomena presented by the Hominidae has
been observed, and in the larger Simiidae the transitory teeth correspond in
number to those found in the milk dentition of the Hominidae. The
differences hitherto noticed affect the sequence in which the replacement
of the transitory by the permanent teeth occurs.

To return to the teeth of the Orang-utan, we note (cf. Fig. 71) a large
diastema or interval in front of the upper canine teeth : the two upper pre-
molar teeth resemble one another more closely than in some forms previously
dealt with (e.g. Cercopithecidae). Both are bicuspid and furnished with three
roots ; in both the antero-posterior diameter of the crown is diminished : in
the first of the two, the outer or labial cusp surpasses in size the lingual
cusp. Like the remaining post-canine teeth, the crowns of the premolar teeth
are marked with fine erenations.

1 This is seen in a specimen in the writer’s possession.

128

THE DENTAL SYSTEM OF THE PRIMATES

[SECT. A

The ciowns of the three molar teeth exhibit crenate markings in a degree
which is peculiar to the Orang-utan among the Simiidae and in which it

Figs.

92.

93.

94.

95.

Fig. 92. Right upper canine and post-canine teeth of an Orang-utan (ad. g
W.L.H.D. priv. coll.).

Fig. 93. Left lower canine and post-canine teeth of an Orang-utan (ad. g
W.L.H.D. priv. coll.).

Fig. 94. Right upper canine and post-canine teeth of a Gorilla (ad. g W.L.H.D.
priv. coll.).

Fig. 95. Left lower canine and post-canine teeth of a Gorilla (ad. g W.L.H.D.
priv. coll.).

is most nearly approached by the Chimpanzee. This crenation is the ex-
pression of folding of the enamel covering the crown and is a feature of
practically all developing molars in the Primates. Its persistence thus
constitutes the retention of an embryonic condition. When strongly marked,

129

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

and individuals present much variation in this respect, the features of the
dental crown are hereby obscured. Nevertheless it is possible to make out
some other points in the conformation of these teeth. The crowns are nearly
equilateral and traces of four cusps are commonly seen. The first and third
molar teeth are nearly equal in size and both are smaller than the second : the
last tooth seldom fails to bear signs of degeneration. Of the cusps, the
antero-internal and postero-external are joined by an oblique ridge similar to
that seen in Hylobates. The postero-internal cusp shews signs of degeneration
and reduction (it may be replaced by several minute eminences) before these
are exhibited by the other cusps.

The lower canine tooth is long and tusk-like. The first premolar tooth is
pyramidal, and the labial cusp far surpasses the lingual cusp in size. The
two cusps of the second premolar tooth are subequal in size, and a suggestion
of a posterior projection, or talon, is seen as in Hylobates. Crenation is seen
as in the upper post-canine series.

The molar teeth are longer than they are wide, the last tooth being the
smallest. The cusps are five in number, and the posterior intermediate cusp
is often found to be much reduced in prominence in the last tooth.

In the Orang-utans supernumerary molar teeth are extraordinarily frequent,
and particularly so in the male sex : the additional tooth is usually placed be-
hind the third molar. This subject will be further discussed in connection
with anomalies of the dentition (p. 138). The great length of the roots of all
the teeth has been remarked as a characteristic feature of the dentition of the
Orang-utan (cf. Tomes, Dental Anatomy, ed. 1898), while reference to Figs.
92 and 93 shews that the Orang-utan provides an excellent illustration of the
comparatively gradual transition and transformation from one type of tooth
to another. ( v . infra, p. 143.)

ANTHROPOIDEA. Simiidae. Gorilla savagii.

Dental formula : i, § ; c, ; pm, § ; m, § . (Figs. 94 and 95.)

In the replacement of the deciduous (milk) teeth by those of the per-
manent series it is to be noticed that whereas in the Hominidae the canine
teeth are replaced before the third molar tooth appears, yet in Gorilla
these events occur in the reverse order. In the male Gorilla (adult) the
canine teeth are enormously developed and the diastema is very evident.
The upper premolar teeth bear two cusps, labial and lingual in position,
but it is to be remarked that suggestions of two other cusps of minute size,
situated behind these, are not uncommonly present. The labial cusps are
the larger. The premolar teeth have three roots. The molar teeth are
quadricuspid and the cusps stand out with peculiar distinctness : the oblique
ridge joining the antero-internal and postero-external cusps is likewise un-
mistakeable. Measurements of a number of specimens shew that the last
molar tooth is smaller than the first, the second being the largest of the
three ; so that the reduction that has been so often noticed in this tooth

D. M.

130

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

is present in the dentition of Gorilla. The molar teeth are implanted by
three divergent roots.

The lower premolar teeth differ not a little in appearance from one
another. The first is pyramidal and bears one well-defined cusp: in the
second tooth the two cusps are nearly equal in size, and behind them a
small talon projects. The molars are comparatively narrow, and elongated
antero-posteriorly : they commonly bear five cusps, the anterior pair of which
are to some extent united, and at the same time leave the three posterior
cusps isolated from one another. In some cases as many as six cusps
may be seen, the posterior talon bearing two of these. No confirmation
appears to be given to the statement that the postero-external cusp is earlier
affected by degenerated processes than the postero-internal cusp. (v. ante
p. 125, footnote.) While the statement (cf. Topinard, quoted by Fraipont,
Archives de Biologic, VII. p. 735) as to the progressive increase backwards in
the size of molar teeth does not hold good in the upper series, there is no
doubt that it is true of the lower teeth l.

ANTHROPOIDEA. Simiidae. Anthropopithecus niger.

Dental formula : i, s ; c, [ ; pm, {j ; m, jj. (Figs. 96 and 97.)

As regards the canine teeth similar remarks apply to the Chimpanzee and
Orang-utan. The upper premolar teeth, and indeed the whole dentition, of
the Chimpanzee suggest however the human dentition much more distinctly
than does that of any other Primate. Shortening of the maxillae has
evidently to be recognised, and the crowns of the premolar teeth, when com-
pared with those of Gorilla, are much reduced in the sagittal direction.
These teeth bear outer and inner cusps, while as regards roots a difference
may obtain, the first premolar tooth possessing three roots, the second tooth
having only two.

The molars present a crown of equilateral proportions, the third tooth
being degenerate both in size and in the reduction of the posterior cusps,
of which the postero-external may be more affected than the postero-internal
cusp. (Thus confirmation of the statement to which reference has been
made already, is provided by one of the Simiidae only.) The other molar
teeth bear four cusps, viz., an anterior and a posterior pair, the characteristic
oblique ridge being present as in the other Simiidae. And it is to be
remarked that crenation is often distinct, though less characteristic of the
Chimpanzee than of the Orang-utan. In the mandible, the premolar teeth
are less like the corresponding human teeth than when the comparison is
made with teeth of the upper series. For in the mandible the characters
of the premolar teeth in Chimpanzee are very similar to those of the same

1 The latter statement as well as that made in reference to the relative sizes of
the molar teeth in the Orang-utan is based upon the results of measurement in
adult examples. Five male Gorillas and six male Orang-utans were available.

131

CHAP. VI] THE DENTAL SYSTEM OF THE PRIMATES

teeth in Gorilla, being distinguished chiefly by their smaller size and the
persistence of crenate markings. Very similar remarks apply to the lower
molar teeth, viz., that they resemble the corresponding teeth in Gorilla, but
present crenate foldings of the enamel, and are less elongated in the antero-
posterior direction.

Figs. 96.

Fig. 96. Right upper canine and post-canine teeth of a Chimpanzee (ad. .
W.L.H.D. priv. coll.).

Fig. 97. Left lower canine and post-canine teeth of a Chimpanzee (ad. £ .
W.L.H.D. priv. coll.).

Fig. 98. Right upper canine and post-canine teeth of an aboriginal native of
Australia (Mus. Anat. Cant.).

Fig. 99. Left lower canine and post-canine teeth of an aboriginal native of
Australia (Mus. Anat. Cant.).

ANTHROPOIDEA. Hominidae. Homo sapiens.

Dental formula as in all the Catarrhine Primates : i, f ; c, | ; pm, § ; m, jj.
(Figs. 98, 99.)

It lias been already remarked that the dentition of the Chimpanzee
provides in many ways a transition from the simian to the human modification
of the Primate type. When the human dentition is examined in series with
those of the other Primates, perhaps the most striking and peculiar feature
is the reduction in size of such teeth as are situated anteriorly to the molars,

' 9—2

132

THE DENTAL SYSTEM OF THE PRIMATES

[SECT. A

viz., the premolars, canines, and incisors. Such reduction is doubtless associ-
ated with the change in function determined by the greater freedom of the
upper limb in man, whereby the jaws are relieved, to a larger extent than
in any other Primate animal, of their prehensile function. So too the
distinctive characters of the dentition are correlated with the modifications of
the cranial base to which reference has been made in the preceding chapter.

1 he canine teeth have almost entirely lost the predominance in size that
obtains in the majority of the Primates : and the diastema is no longer
present.

The upper premolar teeth are bicuspid and possess two roots, the molar
teeth being furnished with three roots, which are however in the majority
of the Hominidae, not divergent, but parallel, and in the third molar
may bo reduced to two, which may even be fused into a single peg-
like root.

The molar teeth do not present crcnate markings in the adult : in size,
the second upper tooth is the largest, next to this the first molar tooth, while
the last tooth is practically always degenerate, and may be absent. The
ipper molar cusps are four in number, disposed as in the Simiidae but
commonly less prominent. The oblique ridge is distinct in the two foremost
toeth, but often obscure, or absent from the last tooth.

In the mandible the first premolar is often nearly as large as the canine
tooth, and larger than the second premolar tooth : both are bicuspid and
furnished like the molar teeth with two roots. The molar teeth present
varying relations in point of size : the last is often the smallest of the three;
in form the crowns are less elongated in the antero-posterior direction
than are the corresponding teeth in Gorilla or Anthropopithecus. The cusps
are commonly four in number, and they are distinct, the separating lines
forming a crucial fissure. But in many cases, and particularly among the
primitive and prognathous coloured races, a fifth cusp is found usually on the
posterior margin and between the two normal cusps.

The comparison of the length of the post-canine series of teeth has been
studied by Flower (cf. the Journal of the Anthrop. Institute, 1885), who devised
an index for comparative purposes : this dental index is based on the relation
of the dental length (that is the combined lengths of the crowns of the
post-canine teeth) to the length of the craniofacial axis.

The index is arrived at from the formula :

^ , . . . length of the premolar and molar crowns x 100

Dental index = — ; — = ^-r-r ,

basi-nasal cranial length

and crania are classified according to the numerical value of that index.
Thus the limits of the class divisions are at 42 and 44. Crania with dental
indices of a greater numerical value than 44 are recognised as megadont,
and such crania are found to prevail in the Oceanic-negro races, while when
a comparison is made with the Simiidae, these too (with the exception of
Hylobates, and perhaps only in individual examples of these) are very dis-

133

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

tinctly megadont, the average value of the index far exceeding 44 and rising to
54 or more. (For other data cf. Chapter xiv.)

B. THE INCISOR TEETH.

The formula throughout the Primates is i, §; they are borne by the
premaxilla in the upper jaw.

LEMUROIDEA. Lemuridae. Lemur varius. Fig. 100.

The characteristic features of the incisor teeth of the Lemuridae are as
follows : (a) the upper teeth are extremely small (cf. also the extinct Lemurs,
e.g. Megaladapis madagascarensis, Chapter xvn.), and the median teeth
are separated by a wide gap in the middle line of the face ; ( b ) the lower teeth
are larger and curiously styloid, they are also procumbent, that is, they are

Fig. 100. Incisor teeth of a Lemur. (No. 4, Mus. Zool. Cant.)

Fig. 101. Incisor teeth of Cebus capucinus. (No. 1093, Mus. Zool. Cant.)

Fig. 102. Incisor teeth of a Macacus monkey.

Fig. 103. Incisor teeth of Hylobates miilleri. (ad. g . W.L.H.D. priv. coll.)

directed almost horizontally forward from the mandible and cannot therefore
be of much use as incisor teeth in the ordinary acceptation of the term ; (c) the
apparent occurrence of three incisor teeth on each side in the mandible is
explained by the view which regards the lower canine teeth as having assumed
the morphological characters and the position of lower incisor teeth (it will be
remembered, v. ante , p. 124, that the succeeding tooth, the first premolar, has
to some extent replaced the normal lower canine teeth).

ANTHROPOIDEA. Cebidae. Cebus capucinus. Fig. 101.

In the Cebidae the disparity in size between the upper and lower incisor
teeth (as described in the Lemuridae) is not to be seen, but there is still a
slight tendency (quite distinct in Pithecia) to procumbency in the lower
incisors (cf. Fig. 21).

The median teeth are provided with chisel-shaped crowns, the lateral with
conical crowns : the latter crowns when worn down by use quickly assume a
chisel-like edge, but in the unworn condition their frame is as described.

134

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

These remarks regarding the crowns of the teeth apply to the Cercopithecidae,
and to Hylobates, Simia, and Gorilla, hut not to Anthropopithecus or to the
Hominidae.

The combined upper series is wider than the lower set. Of the upper four
teeth, it is to be remarked that no median gap remains and that the outer
(lateral) teeth are smaller than the median pair, while the outer angle of the
crown is more open in the lateral than in the median teeth. Of the lower
teeth the lateral surpass the median pair in size.

ANTHROPOIDEA. Cercopithecidae. Cercopithecus. Fig. 102.

The lower incisor teeth are still less forwardly inclined in the Cerco-
pithecidae (cf. Fig. 28); the upper median incisors, as in all the Anthropoidea,
are in contact and the upper median teeth much surpass the lateral teeth in
size. The median and lateral lower incisor teeth are nearly equal in bulk, the
lateral pair being rather stouter than the median.

ANTHROPOIDEA. Simiidae. Hylobates (mulleri). Fig. 103.

The incisor teeth have the general characters of those of Cercopithecidae.
It is to be noticed as a difference (cf. Fig. 102 with Fig. 103) that in the latter
the crown is much more extensive in the vertical direction, both absolutely and
relatively. The comparative smallness of the crown is seen again in the
Otang-utan.

ANTHROPOIDEA. Simiidae. Simia satyrus (Orang-utan). Fig. 104.

The median upper incisors far surpass the lateral incisor teeth in size : the
small size of the upper crowns is very remarkable. Of the lower teeth the
median pair exceed the lateral pair in bulk.

Fig. 104. Fig. 105.

Fig. 104. Incisor teeth of au Orang-utan. (ad. s . W.L.H.D. priv. coll.)
Fig. 105. Incisor teeth of a Gorilla, (ad. s . W.L.H.D. priv. coll.)

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

135

ANTHROPOIDEA. Simiidae. Gorilla savagii. Fig. 105.

The difference in the sizes of the median and lateral upper incisor teeth is
less marked in the Gorilla, but the median pair are still the larger. In the
lower series the opposite proportion obtains. The upper crowns are more
extensive than in Hylobates and Simia, and recall the type found in Geico-
pithecidae.

ANTHROPOIDEA. Simiidae. Anthropopithecus Niger. Fig. 106.

The upper median teeth are larger than the upper lateral teeth ; the
crowns are extensive as in Gorilla; of the lower teeth, the median and lateral
pair are nearly equal in bulk. It is very noteworthy that in the Chimpanzees,
the incisor teeth may often equal or even surpass in bulk the incisor teeth of
the male Gorilla, while the molar teeth and indeed the whole skull ol the
Chimpanzee is much smaller than that of the male Gorilla.

Fig. 106. Incisor teeth of a Chimpanzee, (young ? . W.L.H.D. priv. coll.)

Fig. 107. Incisor teeth of an aboriginal native of Australia. (Mus. Anat. Cant.)

ANTHROPOIDEA. Hominidae. Homo sapiens.

An aboriginal native of Australia (Fig. 107). The upper median incisors
are but slightly larger than the lateral incisors ; the crowns are extensive ; of
the lower teeth, the lateral pair slightly exceed the median pair in bulk.

It has not been possible to describe in detail the features of the milk or
transitory dentition in the several forms just considered. It must suffice
therefore to state that the milk teeth, while fewer in number than the per-
manent teeth, yet resemble these to some extent in form. As is well known,
the milk dentition of the Hominidae is completed (usually at the 20th
month of life) by the acquisition of two incisors, a canine and two molar teeth
on each side above and below, the formula (i, f ; c, j- ; m, f ) thus differing from
that which obtains in adults (i, \ ; c, ^ ; pm, § ; m, :j). Of the several teeth,
the incisors and canines resemble closely enough those by which they will be

136

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

succeeded ; but with rega,rd to the molar teeth, such is not the case ; and the
milk-molar teeth are succeeded by premolar teeth of the permanent set, not
represented in the transitory dentition. These milk molars are moreover
definitely molar in form, bearing four cusps, not two as in the replacing teeth.
The advent of the permanent dentition is marked by the appearance of the
first permanent molar tooth, which comes into position behind the last of the
milk molar teeth.

Thus far the agreement between the Hominidae and Simiidae is complete,
and in Fig. 32 (p. 46) the transition period in the skull of the adolescent
Gorilla is represented ; while Fig. 73 (p. 108) represents crania of Gorilla and
Chimpanzee at an epoch in which the first molar tooth of the permanent series
has established its position definitely.

From the subject of the replacement of teeth we must turn to that of
variations1 in the dental system, and these may be suitably set forth under
the several headings of (a) Varieties in number, ( b ) Varieties in form,
(c) Varieties in position, the permanent dentition being in all cases considered2.

(A.) Varieties in number. These may be of two kinds, viz. (a) where
the number is increased , (/3) where it is diminished. It will be convenient to
consider («), the cases of increased numbers first. Adopting the same order
as was taken in describing the characters of the teeth, the canine teeth must
first be considered. Little is to be said here, as this region of the dental series
seems little liable to variation. In the skull of a Gorilla at Hamburg the
unusual anomaly of reduplication of the canine tooth is to be seen : there is no
question of the retention of the milk-canine alongside the permanent tooth :
but I am not aware that a parallel instance has been noted in the Ho-
minidac.

Additions to the premolar series might be expected a priori, in view of the
prevalence of three premolar teeth in the Cebidae, Hapalidae and Lemuroidea.
As a matter of fact, an additional premolar tooth is of by no means un-
common occurrence3, and such an anomaly may be regarded as of reversionary
significance.

Not only may complete accessory or supernumerary teeth occur in the
premolar region, but small dental masses too small and imperfect to be called

1 The dental system in certain Cebidae, in Simiidae and Hominidae is liable to
much variation, as many as 4°/0 of examples in Cebus and Ateles, and 8 °/ 0 among
the Simiidae presenting instances of supernumerary teeth (Bateson). For a
detailed account, cf. Bateson, “Materials for the Study of Variation,” In addition
to this work that of Magitot, Anomalies clu systeme dentaire, remains of classical
value.

2 Guttmann, quoted by Kiikenthal (Jahresberichta fiir Anatomic, 1901), has
recorded a case in which nearly all the milk teeth were retained iu the presence of
their successors in a youth aged 19.

a Cf. Magitot (op. cit.) for a very remarkable instance of supernumerary
premolar teeth in the skull of a negro.

137

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

teeth1, also appear with some frequency in Melanesian crania, especially be-
tween the last premolar and the first molar teeth in the maxilla. Of such cases,

Fig. 108. Fig- 109.

Fig. 108. An accessory dental mass (x) in the maxilla of a native of New
Britain. (Mus. Anat. Cant. W.L.H.D. del.)

Fig. 109. Two accessory dental masses (x, x) in the maxilla of a native of New
Britain. (Mus. Anat. Cant. W.L.H.D. del.)

Fig. 110. Accessory cusps in the molar teeth of an Egyptian. (Mus. Anat.
Cant. W.L.H.D. del.)

1 Windle (J.A. and P. vol. xxi. p. 84) distinguishes very appropriately between
“supernumerary” imperfect teeth and “supplemental” teeth of size commensurate
with those adjacent to them.

138

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

PiUPnj-flcc.DeQt.Mas.
car

examples are shewn in Figs. 108 and 109 : in the former instance a dental mass
is seen on one side only (x. Fig. 108), while in the specimen represented in
Fig. 109 the masses (x, x) are bilaterally symmetrical. To Fig. 109 I have
appended Fig. 110, which represents the upper teeth of a young Egyptian
man. If the figures be compared, it is hard to avoid the impression that
the small masses in Fig. 109 may be derived from the molar teeth and that
the projections from the cingulum (marked Acc. cusp in Fig. 110) represent
the initial stages in the evolution of independent elements. Otherwise
if on the lingual side of the gums they may
represent elements of the “ post-permanent ”
dentition. At present there seems no means
of deciding between the several possibilities.

It remains to remark that precisely similar
masses are to be found in the crania of Si-
miidae, and that just as among the Homi-
nidae the maximum of frequency obtains in
the Oceanic-negro races, so in the Simiidae,
the frequency is greatest in the Gorilla' (cf.

Fig. ill). It will be noted in this illustration
that whereas one such dental mass is situ-
ated in the position already described, the
second intervenes between the two upper pre-
molar teeth. Additions to the number of
molar teeth may be by way of gemination, of
which a good instance exists in an European
skull (from Paestum) in the University Museum of Anatomy, while a

Fig. 111. Left upper teeth of
a young Gorilla : accessory den-
tal masses are situated between
the first and second premolar
teeth, and between the second
premolar and the first molar
tooth respectively. (W.L.H.D.
priv. coll.)

Fig. 112. Gemination of the last molar tooth in the mandible of an Orang
utan (Selenka Coll., Munich).

1 Cf. Duckworth and Fraser, Proc. Cavil. Phil. Soc. 1900.

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

139

striking instance is shewn in the Fig. 112, which represents gemination in
the last molar tooth in the mandible of an adult Orang-utan. The original
forms part of the Selenka Collection at Munich.

Completely-formed accessory molar teeth are not common in the
Hominidae, although the palate and alveolar arcade in many crania of
aboriginals of Australia seem to be spacious enough to accommodate them.
It is however in the cranium of such an aboriginal native that Sir William
Turner records the occurrence of no less than three accessory molar teeth,
and such anomalies are more frequent in the Melanesian and Australian
aborigines than in other Hominidae. In the Simiidae, accessory molar teeth
are not uncommon, but the frequency of the occurrence is very variable :
in the Orang-utan (cf. x, Fig. 113) the frequency of occurrence is at a inaxi-

113. Mandible of an Orang-utan (ad. s ) with an accessory molar tooth on the
right side. (Hose Donation II. Mus. Anat. Cant.)

Fig. 114. Accessory teeth in the maxilla of an Orang-utan. (Selenka coll-
Munich.)

140

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

mum, particularly iu the male sex, in which nearly fifty per cent, of cases
will be found to present this anomaly. This statement is based on the
examination of the very large collection (more than 200 crania) at Munich,
in the course of which the very remarkable example shewn in Fig. 114
was discovered. In this example four fully-formed molar teeth are seen :
behind the last of these is an aborted dental mass, and behind this a
depression which had probably contained yet another dental mass1.

It remains to consider additions to the incisor series. Supernumerary
incisor teeth constitute a large proportion of the anomalies of the dental
system, and as in the preceding categories, care must be taken to distinguish
between veritable cases of accessory teeth,
and instances where the apparently super-
numerary tooth is merely a retained tooth
of the milk dentition. The distinction is
not always easy to draw, and an instance
of this is shewn in Fig. 115, where how-
ever the length of root exhibited by the
supernumerary tooth is evidence against
the case being ono of retention (for the
milk teeth are not so deeply rooted as
those of the permanent series, and the
root is subject to a process of phagocytic
absorption which in fact leads to the ulti-
mate separation of the deciduous tooth
from its articulation). Supernumerary in-
cisor teeth present another problem of some interest : viz., as to which of
the three incisor teeth so common in the Eutheria, has been suppressed so
as to leave the two incisors (on each side and in each pair) of the dentition
of the Primates. It must suffice to mention that the literature of the subject
shews that each of the three primitive incisor teeth has been claimed as the
defaulter.

As regards Ij (the median incisor tooth), it may be remarked that the
wide interspace in the lemurine dentition between the upper median incisor
teeth is suggestive, and that a supernumerary incisor tooth is not infrequent
in this situation. Gadow adopts this view (and, I believe, Lydekker also) ;
Elliott Smith has recently recorded, while the present writer has observed,
instances of a supernumerary incisor tooth in the position indicated.

The view that I2 is the missing tooth is supported by Turner, Albrecht,
and Wilson and is based largely upon considerations of the arrangement

Fig. 115. Mandible of an abori-
ginal Australian, with a super-
numerary incisor tooth. (Mus.
Anat. Cant.)

1 Since examining the specimens at Munich I find that Selenka in describing
his Collection has commented upon the remarkable frequency of the occurrence of
additional molar teeth in male Orang-utans. Selenka states (“ llassen und Zahn-
wechsel des Orang-utan,” Silz. der kais. preuss. Akad., Berlin, 1896) that the
anomaly is present in 20 per cent, of male crania.

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES 141

of the incisor teeth in cases of persistence of the suture dividing the pre-
maxilla and maxilla (hare-lip)1.

Windle (J. A. and P., vol. xxi., p. 84, et seq.) favours the view that
I3 has been suppressed ; this view rests on the fact that the pre-canine
space is a common locality for the occurrence of supernumerary teeth ; while
if it be granted that the characters of the teeth merge by insensible grada-
tions into one another, the space in question is indicated as the probable site
of the missing tooth which should provide the transition stage (at present
lacking) between the definitely incisor and canine types of tooth-crown.

In regard to other anomalous conditions of the incisor teeth, records
of gemination (cf. “gemination in the molar teeth,” p. 139, and Fig. 112) of
these teeth are noted by Windle ( J . A. and P. vol. xxvm., p. 374).

(/3) Variation by way of defects. In the descriptive notes, the reduction
in the number of cusps of the third upper molar tooth was frequently a
subject of reference. The reduction may proceed to such a length that the
tooth in question may be entirely suppressed. This is the commonest
dental anomaly in the above category, and the frequency of its occurrence
is at a maximum in the white races. Not only is this the case, but in the
same races, there is a distinct tendency for the lateral incisors to disappear2.
These phenomena are dependent very largely upon the progressive reduction
of the maxillae, a process which has not yet been arrested. The normal
dental formula thus tends to change, and to replacement by the formula
presented by such anomalous examples, viz., i, 1 ; c, 1 ; pm, § ; m, |3. These
anomalies are more frequent in the maxilla than in the mandible, and it may
be remarked in conclusion, that the loss of these teeth is not observed in the
dentition of the Simiidae.

IB.) Dental Variation in form. The principal variations included in
this category depend on the conformation of the various cusps in the pre-
molar and molar series. Instances of gemination have been considered in the
preceding section, and require only mention in the present connection. In
certain of the Hominidae the incisor teeth are distinguished by their
enormous size and curiously spatulate form. (Cf. Miklucho-Maclay : Zeits.
fur Ethnoloyie, Bd. vm., see also Chapter xiv., infra.) This has been
observed among men of Melanesian origin, and a similar condition may
be seen in the teeth of an aboriginal native of Australia in the University
Anatomical Museum.

lor expositions of this subject cf. Windle, J. A. and P., vol. xxi., and
Tomes, Dental Anatomy.

- Cf. inter alia, Rosenberg, Morphol. Jahrbuch, 1895.

3 Even such a reduced dentition is surpassed by that of Daubentonia
(Gheiromys, or Aye- Aye, a Lemuroid Primate-form).

142

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

(C.) Variations in situation. Displacement of teeth is rendered
probable in cases in which the space available for their implantation is
diminished without actual suppression of some of the teeth. This con-
sideration pro\ ides an explanation of many cases of the occurrence of teeth
in unusual situations, but is not altogether accountable for displacements
observed in certain instances among the black races, in which the jaws are
large and the space extensive.

The Anatomical Collection of Cambridge University includes examples of
such occurrences in crania of aboriginal natives of Australia. In one such
skull the canine teeth emerge on the facial surface of the maxilla, and their
diiection has been so altered that they lie in the horizontal rather than
in the vertical plane. 1 lie same Collection contains the cranium of an
ancient inhabitant of Peru, which presents a precisely similar condition of
the same teeth. Again, the third molar tooth may emerge on the facial
surface of the maxilla, immediately below the malar process : instances of
this have been seen in an ancient skull from a cave in Jamaica : as also
in the cranium ol an aboriginal native of Australia (in the possession of
Dr Haddon); while the same condition obtains in the skull of an Orang-utan
in the Museum at Amsterdam.

The incisor teeth are subject to similar variations in position. Of these,
perhaps the most striking are present in two crania from the Melanesian
island of New Britain : in each of these specimens an incisor tooth has
emerged, not on the alveolar margin of the maxilla, but on the lower margin
of the apertura pyriformis nasi : in each case, however, the tooth is imperfectly
formed.

The occurrence of teeth, more or less perfectly formed, in dermoid cysts
and ovarian tumours, brings us into the domain of pathology, which must be
regarded as beyond the scope of the present account.

From the foregoing descriptions it appears that the Hominidae,
judged by their dentition, fall naturally into line with the Simiidae
and indeed with the other Primates, the distinctive features of the
human dentition being largely dependent on the characteristic
reduction of the maxillary apparatus in this family (Hominidae).

There remain for consideration certain problems of general
interest, viz. the evolution of the different types of tooth such as
incisors, canines and the like, and also the origin of the characteristic
phenomenon of the replacement of one set of teeth by another.
We have seen1 that the teeth are, in the Primates, naturally
divisible into four classes (incisor, canine, premolar, and molar
teeth) for the most part easily distinguishable, though at the same
time there may be seen, even in a single jaw, such as that of an

1 Chapter hi.

143

CHAP. Vi] THE DENTAL SYSTEM OF HHE PRIMATES

Orang-utan ( v . ante Figs. 92 and 93) evidence of a transition in
type from one class to another. Such animals as present these
variations in their normal tooth forms are described as heterodont,
and are hereby distinguished from homodont animals, the latter
possessing teeth of one pattern only ; and usually it is found that
homodont teeth are present in large numbers disposed along an
elongated jaw.

Again, the animals in which replacement of a milk set of teeth
by a permanent series has been observed, are referred to as
diphyodont, in distinction from monophyodont animals, in which
but one set of teeth is seen. The Primates (including Man),
and indeed most of the higher mammals are heterodont and
diphyodont.

In the endeavour to explain the origin of the different forms
of teeth, such as the incisor, canine, and molar series, in other
words in the attempt to render a clear account of the historical
development of the heterodont dentition, it is tempting enough
to refer all the various forms of teeth back to a simple ancestral
parent-form; and the simplest form known is the conical1 peg-like
tooth found repeated in series with practically no variation (homo-
dont)2, throughout the length of the slender jaws of the toothed
whales : moreover the reasonableness of this view seems enhanced
by the fact that many reptiles (and a reptilian stage is postulated
in the most widely-accepted view3 as to the ancestry of the
Mammalia, cf. the scheme in Chapter III. p. 30) possess such
simple teeth, which are often described as haplodont4. Most
reptiles are thus homodont, and it is from these, and not from

1 It appears that Eutimeyer first suggested that the conical tooth represents
the ancestral form, cf. Forsyth-Major, Proc. Zool. Soc. 1893.

2 Leehe, Bibliotheca zooloi/ica, 1895, demurs to the view that the homodont
condition is the original mammalian one.

3 The fact must not be ignored that certain observations suggest a direct origin
of the Mammalia from the Amphibia, Reptilian ancestors being thus omitted from
the direct line of descent.

4 It is noteworthy that in many reptiles the teeth are anlcylosed with the jaws,
whereas in mammals the teeth are thecodont, that is are implanted in sockets, this
being a form of articulation (not an ankylosis) known as Gomphosis. The
difference between mammals and reptiles in this respect is not however absolute,
for the Crocodilia are thecodont.

144

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

the rarer heterodont reptiles, that descent is traced by Cope (c£
Factors of Evolution, p. 331 J).

Although, as a matter of detail, the theory which regarded
the conical teeth of Odontoceti (toothed whales) as the parent
form has been modified (a brief note on this subject is here
appended)2, nevertheless the prevalent view refers back the

1 Other morphologists, on the other hand, submit that the heterodont fossil
reptiles known as Theriodontia, should be regarded as representative of the stock
whence the Mammalia have sprung. The Theriodont reptiles present affinities
with the Prototheria, and also with certain extinct Amphibia (cf. note 2 on this
page ; also, Woodward, Vertebrate Palaeontology , p. 247).

2 The toothed whales (possessed of a liomodont dentition) were at one time
thought to lack a milk set of teeth, and were accordingly regarded as mouophyodont ;
but Kiikenthal’s researches shew that they are really heterodont and also
diphyodont, the first or “milk” set appearing as the normal teeth of these animals,
while the second set of teeth is vestigial only. Moreover, Kiikentbal (cf. Denkschr.
der med. naturwixx. (lex. in Jena, Band 3, 1893, quoted by Schwalbe; Anat.
Am. 1894; also Jenauche Zeitxchr., Band xxvm. 1893, p. 76), found that even
whalebone whales are provided with tooth-germs which early abort. These
researches, together with those of Leclie, indicate that the whales are the descendants
of ancestors provided with more complicated teeth than those of the toothed-
wliales, and Kiikenthal supposes that the numerous conical teeth of the latter
result from the splitting up of several compound teeth. This suggestion is
however by no means generally accepted, and in particular, Osborn and Gadow
reject it. The Metatheria (Marsupials) appear to be monophyodont, but it has long
been known that their most posterior premolar tooth is replaced : moreover Leche,
Hill, and Wilson have discovered traces of other teeth which do not attain
functional perfection. The Prototheria provide some evidence in the same direction,
and in fact it is stated by Tims (J. A. (£• P. vol. xxxv. p. 321) that no mammal has
yet been shewn to be absolutely monophyodont. Moreover, in addition to the two
sets of teeth so characteristic of the Eutherian mammals, vestiges have been
discovered of two other series, which may be described as constituting a “pre-milk”
and a “post-permanent” set respectively. This discovery, which we owe to the
work of Rose and Leche, has increased the complexity of the problem of deciding
which sets of teeth are homologous in mammals of the various sections : and in
particular, the identification of the ordinary set of teeth of Marsupials is still
a matter of controversy. It is also to be remarked that according to the respective
researches of Tims and Rose, the human foetus possesses unmistakeable vestiges
of representatives of both pre-milk and post-permanent series, and it is a
characteristic feature of the abortive tooth-germs that the so-called pre-lacteal
germs should be developed on the labial side of those germs which proceed to
become functionally active, while the post-permanent representatives are placed on
the lingual side of the permanent teeth.

In his exhaustive article in the Bibliotheca zoologica (Heft 17, 1895, Stuttgart),
Leche remarks that in the four dentitions (which he distinguishes by Roman
numerals I— IV), the several elements develop as follows:

145

CHAP. Yl] THE DENTAL SYSTEM OF THE PKIMATES

various modifications of the teeth to a simple peg-like type, and
the problem is resolved into the demonstration of the evolution of
the complicated teeth found in modern mammals, from such

No. I. The teeth do not attain the stage of calcification, and are represented
by vestigial buds only, situated upon the labial margin of the gum.

No. II. is regarded as the ordinary “ milk ” dentition.

No. III. is the ordinary permanent dentition.

No. IV. This series is usually represented by “buds” on the lingual side
of No. III.: these elements may sometimes arrive at maturity and appear as
definite teeth. Subsequently (in the same memoir) Leche discusses the subject
of the reduction in the number of functional dentitions. He suggests that the
reduction was necessitated by the circumstances under which the mammalia were
evolved from pre-mammalian reptilian ancestors ; that however, only dentitions
I. and II. have been inherited from such ancestors, III. and IV. being newly-
evolved and peculiar to the mammalia. This position is not quite easy to grasp in
view of the fact cited by Beddard ( Mammalia , p. 53), that Leche has himself
described in a reptile (Iguana), no less than four series of teeth which reach
maturity, while a rudimentary (or vestigial) series, antecedent to these, never
produces fully formed teeth.

But in the memoir quoted, Leche defends his position that new dentitions can
arise, though he recognises the objections that have been adduced by Kowalevsky,
Schmidt, and Schlosser. Finally, in a more recent memoir ( Bibliotheca Zoologica,
Heft 37, 1902) upon the dentition of the Insectivora, Leche brings forward further
evidence in support of the foregoing view.

These discoveries of a number of dentitions, some of which are recognisable in
the Hominidae, detracts to some extent from the value of Schwalbe’s review of the
subject as presented to the German Anatomical Society in 1893. Nevertheless
that address still retains all its historical interest, and includes certain remarks
which may here be briefly recapitulated. In the first place, Schwalbe points out
the difficulty in determining criteria for the several series of teeth. He quotes
Leche as pessimistically admitting that such criteria are not to be hoped for,
though the same author clearly indicates that he regards each dentition as a tooth-
generation. This question of the criteria is still a matter of discussion (v. infra.
p. 150, footnote). Schwalbe emphasises the significance of the independence of the
milk and the permanent series as regards their original positions, and this
independence would seem to be extended to the other dentitions subsequently
discovered. A large part of the memoir is devoted to a discussion as to whether
the ancestral mammals had one or two dentitions, but this part of the question is
of course no longer relevant, except as regards one point. For in drawing up
a table of the several schemes which have been devised to shew the originator’s
views regarding the relations of the permanent to the milk-teeth, Schwalbe shews
that he regards pre-molar and molar teeth as derived from conjoined elements from
the two dentitions (v. infra , p. 152). Kiikenthal has, I believe, shewn evidence
of such a coalescence in a special instance, but otherwise the subject has not been
finally decided.

The history of the evolution of the several series is thus to a large extent

146

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

primitive haplodont teeth, which were probably arranged in
considerable numbers along the elongated jaw of the ancestral
form.

Turning now to the dentition of the Primates, and especially
to the higher members of the Order, it is intelligible that the
process of reduction in the size of the jaws (a reduction which is
contingent upon the gradual loss of the prehensile function,
compensation for which is found in the increased activity of the
fore-limbs), determined the reduction in the number of teeth, a
process which still persists in the Hominidae.

As regards the form of the teeth : in the incisor and canine
series the change from the original haplodont form has been com-
paratively slight, though whether the result has been determined
by natural selection, or use-inheritance, would lead into a discussion
upon which we cannot enter here.

But in the premolar and molar series the difficulties are greater :
for the problem is to determine the origin of complex many-
cusped teeth with multiple roots, from conical teeth with single
roots.

The explanations which have been offered may be grouped
under three headings: viz. the hypotheses of Trituberculy, of the
Polybunodont origin of the teeth, and the hypothesis advanced
by Marett Tims, with which the Concrescence theory will be
considered.

It must be at once stated that no one hypothesis will cover all
the cases, and hence it is necessary to enter into brief notices of
each.

The tritubercular hypothesis is inseparably connected with the
names of Cope and of Osborn1, two American palaeontologists,

obscure : the general significance of the replacement of one dentition by another
must evidently be found in the advantage therefore conferred on the animal, which
is thus able to bring series after series into use, as the preceding set is lost or worn
away. And whether two, or all four of the dentitions recognisable in the
Hominidae, are inherited from ancestors in the reptilian phase or no, tho general
conclusion must be that the multiple dentition has been inherited from polyphyodont
ancestors, and has subsequently been modified iu accordance with the special needs
of this family of the Primates.

1 Cf. Cope, Primary Factors in Evolution ; Osborn, American Naturalist, 1888,
p. 1074 ; ibid. 1893 and 1897.

147

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

and it is interesting to note that the theory is largely a
generalization from the experience of extended investigations of
the characters of fossil teeth. It may be stated in the
following way.

Starting from the simple haplodont tooth, it is pointed out
that the arrangement of these teeth is such that the members of
the upper and lower arcades alternate: the result of this alternation
is that each tooth will be touched by two others when in action,
and this contact will be at the anterior and at the posterior
surfaces.

To the mechanical irritation of such contact, an appeal is made

for an explanation of the two

subsidiary processes or cusps

found in the next successional

r ~ ‘

o”!

j” 1

stage, in which the primitive

\P Vs*^,l

cone is supplemented by a small

; (

p) ;

O p)

anterior cone, and a similar
posterior cone, as shewn in

Lva/Tj

Fig. 116, where the central

circle represents the primitive

Fig. 116.

Fig. 117.

cone of an upper tooth, the

Figs. 116, 117.

Diagrams of the primi-

smaller circle or cone (ly), being tive molar CUSPS> shewing the change in
' . . . ° position which gives rise to the trituber-

antenor, and that marked (m) cular type of molar tooth.

being posterior.

From this stage, a passage is effected to that represented in
Fig. 117 in which the subsidiary cones have been rotated with
respect to the primary cone. Circumduction takes place in the
direction of the arrows shewn in Fig. 116, and again the mechanical
action of the jaws in mastication is appealed to as an active cause
of the process. Moreover the direction of circumduction differs
in the upper and lower jaw, the tooth in the upper jaw being left
with the secondary cones as shewn in Fig. 117, viz. on its external
surface, whereas in the lower teeth, these cones would be found on
the internal side1.

1 This process has been very ingeniously described by Ryder ( Proc . Philad.
Acad. 1878), as depending on the lateral movement of the mandible across the
maxilla, whereby the small cusps will be swept outwards in the maxilla, and inwards
in the mandible.

10—2

148

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

The primitive cone is designated the protocone (P, Figs. 116
and 117), the anterior subsidiary cone the paracone (P\ Figs. 116
and 111), and the posterior the metacone : a primitive trigon or
triangle is thus formed, and provides the tritubercular pattern which
has given its name to the hypothesis.

The American palaeontologists (Cope, Osborn, and Marsh) are
able to point to a great number of extinct Eutherian mammals in
which this stage has been reached, and among recent Eutheria
(for example, Gymnura), and Primates in particular, it is clearly
recognisable (whatever the path by which it has been arrived at),
as in the molars of the Lemurs, and indeed in certain cases in the
molars of the Hominidae. j

From this point however, the lines of evolution appear to
diverge, and to differ in the upper and lower teeth. Essentially,
the changes consist in the addition of further cusps, which are
regarded as derived from the cingulum, an elevated zone or band
which encircles the crown of the tooth, usually at the lowest part,
where the crown gives place to the root. (The cingulum is already
present in the haplodont conical tooth.) Cope and Osborn have
traced the development of the (subsequently) strongly-contrasted
Ungulate and Carnivorous types of molar tooth, from this common
stage, but it would not be appropriate to enter here upon this
subject. Coming now to the Primates, and considering the lower
molar teeth (cf. Figs. 116, et seq.) we note the tendency to the
production of four or even five cusps. The cusps thus added are
formed at the posterior end of the tooth, on a process of the
cingulum which is known as the talon. Upon this talon a fourth
cusp is developed ; in position it is postero-external and is thus
shewn in Figs. 119 and 121 (in Fig. 121, it is indicated by PE)]
and yet further cusps may be added, the fifth usually assuming an
intermediate position marked by y in Fig. 119 and Acc. in
Fig. 121. This arrangement of cusps is, as we have seen,
found to obtain throughout the lower molars of Anthropoidea
including the Hominidae.

In the upper molar series, the tritubercular arrangement
remains typical in the Lemuroidea, while in the Anthropoidea
(cf. Figs. 85 — 99 inch) a four-cusped tooth is the rule. Moreover
the protocone and the metacone (cf. Fig. 118 AI and PE) are

149

CHAP. Yl] THE DENTAL SYSTEM OF THE PRIMATES

connected by an oblique ridge in the Snniidae and the Hominidae
though (and this is important) not in the Cercopithecidae, nor in
most of the Cebidae, though there are exceptions among the latter.
The fourth cusp is called the hypocone, and Osborn (Am. Nat. 1897)

Fig. 118. Fig. 119.

Fig. 120.

Fig. 121.

Fig. 118. Diagram of the cusps in an upper molar tooth : the indications are
AE, antero-external, AI, antero-internal, PE, postero-external, PI, postero-internal
cusp: “x” represents the position in which additional cusps usually appear, as
seen in Fig. 120, which represents an upper molar tooth. (Cf. also Fig. 96.)

Fig. 119. Diagram of the cusps in a lower molar tooth : additional cusps tend
to appear at “ y ” as shewn in Fig. 121, which also represents a lower molar tooth
with an accessory cusp. For the significance of the letters, cf. Fig. 118.

regards it as a derivative of the cingulum. This hypocone is
indicated by PI in Fig. 118, and the region x (Fig. 118)
may produce other subsidiary cones. Where the tooth is in a
retrogressive condition, as in the third upper molars of Anthro-
popithecus, Pithecanthropus (cf. Chapter xvii.) and Homo, several
degenerate cusps may replace the hypocone, and the appearances
seen in Figs. 96 and 120 represent such a result.

It is convenient to note here that the four-cusped arrangement
seen in the upper molars of the higher Primates, is regarded by
Cope as representing a comparatively early stage in the history of
the complicated molar teeth of the Ungulata In this respect
therefore the Primates are to be regarded as comparatively
primitive.

Leaving the molars for the moment, it must be admitted that
the exact history of the bicuspid premolars is not clearly explained
by Cope in his latest work (The Primary factors of Organic
Evolution, 1896). It is there stated that according to Scott and
Allen, the internal premolar cusps are to be derived from the

150 THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

cingulum, and to this proposition Cope gives a somewhat hesitating
assent1.

The premolars have been largely reduced in number in the
Primates, and especially in the Catarrhinae2; it is noteworthy that
Osborn regards the primitive mammalian dental formula as i, 4;
c, 1 ; pm, 4 ; m, 8 (cf. Oldfield Thomas’ formula : viz. i, 4 ; c, 1 ;
pm, 4; m, 3), shewing hereby that he regards the reduction at the
molar end of the series as very great.

Thus far the application of the tritubercular theory seems
perfectly correct, and the exposition of the subject would be
greatly simplified were it possible to place implicit reliance upon
this theory. But while expressing the conviction that this view
will be ultimately accepted in a modified form as applicable to
the Primates, being largely accountable for the facts observed,
it is impossible to overlook certain grave objections to its un-
reserved acceptance. In the first place, it seems undeniable that
embryologically the cusp first developed is not the protocone,
as should be the case in accordance with the hypothesis (cf. Taeker,
quoted by Osborn Am. Nat., 1893; Woodward, quoted by Tims
J. A. P. xxxvii. p. 137 ; Tims, op. cit. p. 137 ; Heischmann, quoted
by Rose, Anat. Anz. Band VII. p. 394; and Rose, ibid.), nor does
there seem to be any embryological evidence of the circumduction
(often spoken of as the rotation) of the secondary cusps.

It might thus seem that the objections are directed from the
side of embryology only, but Tims (op. cit. p. 138) claims that the
evidence of palaeontology is by no means flawless.

Some of the earlier opponents of Cope’s theory are ranged on
the side of Forsyth-Major, who ( Proc . Zool. Soc. 1.893), for Rodents,

1 The point is of importance, because there is a difficulty in defining the exact
difference between a molar and a premolar tooth. The older writers seem to have
believed that whereas the premolars are preceded by milk teeth, the true molar
teeth are not so preceded. Difficulties in the applicability of this ciiteriou having
arisen, a difference in developmental history was somewhat eagerly seized upon as
an alternative test, but this in turn seems to be a controvertible point, in view of
the researches of Marett Tims (cf. J. A. P. xxxvii. p. 146).

- Brunsmann (quoted by Kiikenthal, Jahr. der Anatomic, 1902) seems to have
postulated a stage in human ancestry in which the dental formula was

i, c, 1; pm, I); m, •$»

and has been engaged with Adloff (cf. Kiikenthal, op. cit.) in controversy on this
subject.

151

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

proposed an alternative theory, known commonly as that of
Multituberculism or Polybunoclontism. Forsyth-Major believed
that the most primitive known mammals are provided with teeth
which, far from being simple cones, are furnished with many small
cusps. Such is the form of the only teeth found among the
Prototheria, and not only in the recent, but in the fossil examples1,
which are by some regarded as the most primitive of known fossil
mammalia2.

It was thus suggested that the several rodent tooth-forms are
to be regarded as derivatives by fission, to a greater or lesser
extent, of a primitive polybunodont mass.

But the difficulties in the way of an application of this theory
to the Primates would appear very great3.

Another view is that of Tims (op. cit. passim ), who was
impressed with the fact that the cingulum is capable of throwing
up offshoots in the form of cusps. This fact is duly recognised by
the exponents of the tritubercular theory both as regards the
pre-molar, and to some extent as regards the molar teeth. Tims
proposes to adopt this explanation as regards the pre-molar teeth,
while as regards the molar teeth, and this is an important point,
he suggests the concrescence of primarily distinct elements placed
originally in an antero-posterior sequence4. Antero-posterior con-
crescence is the keystone of Tims’ theory as regards the molar
teeth, and it must be admitted as unfortunate that the evidence of
concrescence is not yet convincing, except in Sphenodon (a reptile),
and Ceratodus (a Dipnoan fish)5.

Concrescence indeed has been assigned, as a name, to a definite
theory, which would seem (cf. Marett Tims, J. A. P., vol. XXXVII.
p. 134). to have been first advanced by Gervais. Its chief advocates
in later years have been Rose and Kiikenthal, against whom we

1 Osborn deals with this theory in an essay in the American Naturalist , 1897,
pp. 993 et seq.

2 Woodward, Vertebrate Palaeontology , p. 247.

3 Tims (op. cit. p. 139) confirms the application of the theory to the Rodentia.

4 In the Primates and most Entheria concrescence of pairs of such elements
is suggested, while in the Elephants a greater number of elements would appear
to have been fused together.

5 But not in Protopterus, another Dipnoan fish (cf. Rose. Anat. Anz. vii.
p. 399).

152 THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

may set Leche (Bibl. Zool. Heft, 17, pp. 154, 155). The theory
postulates the possibility of primitive conical dental elements
fusing to form complex teeth : and the elements which thus fuse
may belong to one and the same, or to different dentitions.

Rose (An at. Anz. VII. p. 395) declares himself an advocate
of the Concrescence- theory as accountable for the origin both of
pre-molar and molar teeth, and has represented his views in an
elaborate diagram. It may be noted in conclusion of this brief
notice, that Rose postulates the original presence of from 46 — 52
single conical teeth, which by fusion have constituted the dentition
actually found in the Hominidae. Such a number of conical
teeth is submitted to be not by any means unusual in the
dentition of reptiles.

The foregoing notes contain an attempt to set forth in the
most concise manner the several views which have been taken,
and the hypotheses which have been advanced in explanation,
of what is undoubtedly a difficult problem, and one upon which
much light remains to be shed.

The tritubercular theory lias been discussed at greater length
than the other views, partly because of its special applicability
to the Hominidae, and also because of the very important
inferences based upon this by Cope and set forth by him in the
American Naturalist (1893), and again, at a later date, in the
Primary Factors of Orgamic Evolution (1896).

The molar teeth are the special object of study, and Cope and
Topinard agree in declaring that the Hominidae, and especially
the more highly civilised among recent Hominidae, are tending
toward the reversionary condition of trituberculy in the upper
molars, the hypocone (cf. Fig. 118, “PI”) tending to disappear.
Topinard (E Anthropologic, 1892) gives some striking statistics
from a research on several hundred crania, and has drawn
up comparative tables illustrative of the tendency in the several
human races (cf. also Tomes’ Dental Anatomy, 1898) h

This tendency to trituberculy (which is undoubtedly demon-
strable) is considered by Cope2 justification for the inference that

1 Both these writers appear to ignore the earlier work of Zuckerkandl and
Rose (cf. Chapter xiv.).

2 Haeckel and Klaatsch seem to bo in agreement with Cope upon the general
accuracy of this account.

153

CHAP. Vi] THE DENTAL SYSTEM OF THE PRIMATES

the Hominidae and Simiidae have descended directly from Lemurine
ancestors, to the exclusion of a “ Cercopithecus stage” in the
genealogical history of these two families. Extinct lemurs are
appealed to, especially the small animal known as Anaptomorphus
(cf. Chapter xvil.), whose nearest living relative is the very
primitive Tarsier (cf. Chapter II.); also the various representatives
of the Genus Adapis (cf. Chapter xvil.) which command a special
interest in view of the features of their lower incisor teeth1.

From these forms Cope considers that a transition can be reason-
ably claimed as demonstrable, to the extinct Eutherian groups known
respectively as Condylarthra (ancestral ungulate forms), and Creo-
donta (ancestral carnivorous forms), while from the latter the passage
to very primitive or generalised marsupials of a polyprotodont type
(cf. Chapter ii. p. 20 ; Chapter ill. p. 28) is readily intelligible2.

The ancestry of the Hominidae is thus re traceable to a
marsupial stage, and in point of time to the Jurassic period,
beyond which no definitely mammalian remains are forthcoming3.

If, now, the question as to the cause of the differentiation of
distinct dental types in the several regions of the jaws be
investigated, the exponents of the tritubercular theory will be
found to appeal as in other instances to functional adaptation as
the prominent factor at work (cf. Cope, Primary Factors, pp. 319
et seq.). Certainly the mechanical conditions will differ widely in
different parts of the jaw; it is suggested that whereas the
primary need was originally prehension, and that the crocodilian

1 As was mentioned in the descriptive notes on the teeth of the Lemuroidea, the
true Lemurs are distinguished by the very peculiar procumbent position and the
extraordinarily styloid shape of their lower incisor and canine teeth. The pos-
session of this character would be an obstacle to the acceptance of the view which
should postulate the appearance of such Lemurine forms in the ancestry of the
Hominidae. The character has not been lately acquired, for the giant extinct
Lemurs possess it (cf. Chapter xvn.), but Cope (Am. Nat. 1893) is able to shew
that several of the extinct Adapidae possessed a more generalised conformation in
regard to the teeth in question. The typical Lemurine conformation is regarded
as the result of adaptive specialisation.

■ Forsyth-Major (Proc. Zool. Soc. 1893), and Marett Tims strenuously oppose
this view.

3 Cf. Cope, Primary Factors <Pc., p. 141. Representatives of the monotremes
(Prototheria) have been found in the Lower Eocene, but not so far in strata of such
early date as the Jurassic.

154

THE DENTAL SYSTEM OF THE PRIMATES [SECT. A

or cetacean types of dentition provide good examples of this ;
it is urged that with the acquisition and development of the habit
of masticating food ('whether like a primitive insectivore in crushing
the scaly coats of its prey, or a primitive ungulate in reducing
vegetable matter to pulp, or again in the habit of shearing flesh
• from bone as shewn by Carnivora), specialisation and adaptation
were associated in that section of the dental series at which
power could be most advantageously applied ; and it is submitted
that the comparative simplicity of the anterior teeth is contingent
upon the retention of the prehensile function by this portion of
the dental arcade.

So finally, when the dentition of the Hominidae is considered,
the interpretation thus advanced is found to apply to these, equally
with other Eutherian mammals, with the special qualifications
introduced by the factor to which reference has been so often made,
viz. the peculiar degree of reduction of the maxillary apparatus
and the concomitant limitation of its functions.

SECTION B.

EMBRYOLOGY.

CHAPTER VII.

THE EVIDENCE OF HUMAN EMBRYOLOGY.

General considerations. The foregoing chapters have had
as their aim the demonstration of the fact that Man is associated
in a natural zoological classification with certain other mammals
in the Order Primates. It is now suitable to take up the second
subject proposed for consideration in these notes, and to endeavour
to ascertain something of Man’s ancestral history, that is, of the
path of evolution traced by Man. The means available for carrying
out this enquiry are at the present day threefold : (1) embryo-
logy, (2) the comparative morphology of the various human races,
and (3) palaeontology. The importance of the first-mentioned
study, viz. embryology, depends upon the well-known generalization
made by Kowalewsky following v. Baer and Meckel, to the effect
that the individual organism recapitulates in its own developmental
history the several stages through which its ancestors passed in
their evolution. The second study, viz. the comparative mor-
phology of human races may be expected to reveal the most recent
stages only, and to indicate the steps by which the more highly
evolved of human beings have arisen through the modification of
their lowlier and more archaic brethren. The last-mentioned
science supplies information as regards extinct forms of life, some
of which may be regarded as at any rate representative of, if not
themselves actually human ancestors.

156

HUMAN EMBRYOLOGY

[SECT. B

It is thus that the study of human embryology now demands
attention. It follows from the principle of recapitulation which
is set forth above, that the human embryo should provide
material for the reconstruction of the history of the human race,
that the developing human being should pass through every phase
of the evolutionary path trodden by the human family. But
embryological study soon shews that this history is at best
epitomised or abstracted, that certain episodes are glossed over,
certain phases either so abbreviated as to be hardly perceptible,
or actually omitted.

The evidence of embryology must not therefore be expected
to prove exhaustive, and with this proviso, the application of the
recapitulation theory to the special case of Man maybe attempted.
Concerned as we are with the later stages of human evolution,
the later stages of human embryology may be expected to
provide information of the kind required. It may be at once
stated that studied from the general zoological standpoint,
the embryology of Man indicates his descent from an uni-
cellular form of life through invertebrate phases to a vertebrate
series of stages; in certain of the latter, definite resemblances
to a fish-form can be traced; these are followed by other phases,
in which are seen features transitory in the human foetus but
permanent in the lower mammals, and hence indicative that the
path of human evolution has passed through stages corresponding
to these. Following up this train of evidence, it seems reasonable
to suppose that in the progress of human development, periods
occur at which the condition of the foetus reproduces that of the
later or less-removed of human ancestors; and in fact, the con-
clusion is arrived at, that on the hypothesis that evolution is the
method of origin of animal forms, there should be demonstrable
in the human foetus characters distinctive of non-human ancestors
rather than of Man himself. In other words, the human foetus
should present transitorily the permanent morphological features
of lower members of the Primates, and this is the subject now
proposed for consideration1.

1 Should the answer to this enquiry be in the affirmative the validity of the
theory of evolution will be much enhanced : should it on the contrary receive
a negative reply this will not necessarily ring the knell of that theory: foi it

CHAP. VIl] HUMAN EMBRYOLOGY 157

With these preliminaries, we may turn to a matter of practical
study and approach the subject in the form of an examination
into the morphology of the developing human embryo. It
will be convenient to retrace the steps of human development,
and to deal with the human foetus, primarily at the time of birth1,
secondarily at about half-way through its foetal life, and to
enquire what are its morphological characters, and whether these
can be justifiably regarded as more ape-like than those of the
human adult.

The anatomy of the foetus may be most profitably studied
under the following headings :

(a) external features,

( b ) topographical anatomy,

and brief summaries of the results will be appended to each section.

(a) External features, (i) In reviewing the principal dis-
tinguishing external characters of the human infant at birth
the proportionately large size of the head at once claims notice.
The eyes appear more widely separated than in the adult (Blind2).
The nose of the infant is flat and wide, presenting characters
which are retained to maturity by the lowlier human races.
Owing to the relatively diminutive size of the mandible and the
lack of development of the maxilla, the face is broad rather than
long. This appearance is enhanced by the existence of special
encapsulated fatty masses lying beneath the risorius muscle (and
superficial to the buccinator muscles) on each side. They are
termed the “sucking pads.” The trunk is relatively stout, its
parietes are straight in direction and nearly parallel, a condition
retained in the negro races. The umbilicus is situated low down

is possible that the phases in question are hurried over very rapidly, or are even
omitted from the story of human embryology as being comparatively unimportant
events in the history of the human family, events far less impressive at any rate
than the substitution of lungs for gills as the organs of respiration ; or again,
it may be that our observations are not at present sufficiently exact, and that
though the ape-like features are present, yet we cannot recognise them.

1 In the following pages the anatomy of the new-born infant is not distinguished
from that of the foetus during the last month of pregnancy, except as regards the
respiratory and circulatory systems.

2 Hugo Blind, NasenbiUhniy bei Neu-tjeborenen, Munich.

158

HUMAN EMBRYOLOGY

[SECT. B

on the abdominal surface, and the incomplete development of
the pelvis is shewn by the lack of breadth at the hips, and by
the prominence of the abdomen, which at this stage contains
organs, such as the bladder, which are subsequently accommodated
rather in the pelvic than the abdominal cavity. While in the
foregoing respects, the infant differs from the adult, yet the
permanent conformation has been nearly attained in the hand,
which is broad, and provided with cutaneous grooves expressive
of the actions respectively of the flexor, adductor, and opponens
groups of muscles1. The proportions of the foot too are similar
to those of the adult, but the plantar arch still awaits develop-
ment. The hallux is parallel to the other toes, and there are
cutaneous grooves on the plantar surfaces, which are very charac-
teristically inverted. The mobility of the human toes at this
epoch constitutes a merely superficial resemblance to apes, as the
difference in the anatomical conformation of the foot of the human
infant and of the apes precludes absolute similarity. At most, as
Howes has pointed out, the so-called grasping action of the infant’s
hallux is a movement of adduction, unaccompanied by opposition.
The upper limb is almost as long as the lower limb, and
herein lies a simian feature which will be further dealt with in
Chapter xm.

The downy covering of lanugo has been almost completely lost,
and an abundant cutaneous (sebaceous) secretion (the so-called
vernix caseosa) is very remarkable.

The external female genitalia appear to be incompletely
developed as compared with adult examples, the labia majora
being relatively smaller, and exposing the labia minora (Ballan-
tyne). In both .sexes the gluteal fold in the infant is obscured,
owing to the lack of development of the underlying and adjacent
muscles, and the anal aperture is much more prominent than in
later stages. The last-mentioned character must be. claimed as
simian.

(ii) When we pass from the study of the foetus at the ninth
month to that of the foetus at the fourth or fifth month (Fig. 122)
(measuring 150 to 200 mm. in length), we notice that the eyelids
are closed, that the nose is fiat, that the chin lacks prominence, and

1 Cf. Hepburn, J. A. dk P. xxvii. p. 112 ; xxix. p. 31 : also Chapter v, p. 100.

CHAP. VII]

HUMAN EMBRYOLOGY

159

122- A and B, outline drawings of a human foetus (said to be 4>, mouths
ota), from photographs, and of the actual size of the specimen.

C and D, similar drawings (of actual size) of foetus of gorilla.

160

HUMAN EMBRYOLOGY

[SECT. B

that the head is unduly large. The general appearance of the
foetus is almost emaciated as compared with the ninth-month
foetus, owing to subcutaneous fat being scanty in amount in the

Fig. 123. A and B, outline drawings from photographs of palmar and plantar
surfaces of the extremities of a human foetus (No. 29 of the Lee Collection), said
to be 4 months old.

C and D, corresponding palmar (C) and plantar (D) surfaces of the extremities
of a foetal gorilla (Mus. Zool. Cant.).

All these are enlarged from photographs of the original parts. Thus C, with an
original length of 13 mm., has been enlarged 34 times, and D (original length
15 mm.) has been enlarged 3# times. A and B were originally of smaller size
than C and D respectively, but have been enlarged to similar dimensions for
the sake of comparison.

CHAP. VII]

HUMAN EMBRYOLOGY

161

former. Partly owing to a similar reason, the neck looks longer
and thinner at the fourth to the fifth month than at the later
epoch. The sucking pad has not developed sufficiently to give the
characteristic effect to the countenance. The umbilicus is situated
very low upon the abdominal surface, and the breadth at the hips
is small. The hand and foot (Fig. 123) at the end of the fourth
month appear to have nearly attained the proportions which they
exhibit at birth : the plantar surfaces of the feet seem less
inverted than in the later stages, and the distinction from the
hand and foot of the Simiidae (whether adult or foetal) is perfectly
easy and clear. It is uncertain whether the cutaneous grooves,
even at the third month, may not be due to shrinkage caused
by the preservative fluids in which the foetus has been immersed.
The lanugo (a down-like covering of fine hair) at the end of the
fourth month is widespread. The external genitalia of the two
sexes are perfectly distinct, and do not occupy positions similar
to those which they possess in the Simiidae, so that there is
no suggestion at this stage of a closer resemblance to those animals.

The external ear is still imperfect, owing to the union of the
several tubercles to which it owes its origin being still incomplete.
The proportions of the limbs distinctly suggest simian relations,
for the upper limb is relatively to the lower much longer
(varying from 98*6 % to 120 °/0) than in the adult (69 Vo)1.

Conclusions from the external conformation of the foetus
at 9 months, and at 4 — 5 months respectively.

In both stages certain simian characters are recognisable, but.
it is remarkable that the younger stage does not shew these in any
greater frequency or degree than the later stage. The inference
is that though human evolution through a simian stage is
su££este(l> many and essential details are lacking, or at least
are unprovided by the external features.

(b) Topographical anatomy, (i) The topographical anatomy
of the foetus at the ninth month has been studied by Merkel,
Chievitz, Cunningham, and Ballantyne2; the following account is

1 Cf. Chapter xm.

Manual of Antenatal Pathology and Hygiene , 1902. (Camb. Univ. Lib. 310 b
90. 2.)

D. M.

162

HUMAN EMBRYOLOGY

[SECT. B

largely based upon the work of the last-mentioned authority.
Considering the head first in order, the average dimensions of
the cranium (when it has recovered from the distortion attendant
upon birth), are stated to be about 130 mm. in maximum length,
100 mm. in maximum (biparietal) breadth, and 87 mm. in the
temporal region, the latter diameter being unaffected by pressure
during parturition, which may result in very considerable, though
as a rule temporary, modification of the other diameters. The cir-
cumference of the head is from 340 to 350 mm. (Gonner1), (or
rather less; 325, W.L.H.D.).

As regards cerebro-cranial topography, it would appear from
the researches of Cunningham that the angle of the Sylvian
fissure is more acute (62°) in the human infant than in the
adult (67°), and that the posterior limb of the fissure is placed
above the line of the squamous suture, which however it has been
approaching from the time of its earliest formation. The change
is due, not only to the growth of the squamous portion of the
temporal bone, but also to the enlargement of both the fronto-
parietal and the temporal parts of the cerebral hemisphere, an
enlargement in which the growth of the fronto-parietal element
predominates, so that the posterior limb of the Sylvian fissure
moves downwards laterally at the expense of the temporal lobe.
The upper end of the central sulcus is nearer to the coronal
suture than in the adult, but with reference to the cerebral
hemisphere, i.e. its distance from either pole of the hemisphere,
the upper end of this sulcus is remarkably constant in position,
from the time of its appearance. The variation in relation to the
coronal suture is therefore expressive of the variable extent to
which the parietal and frontal bones respectively cover this region
of the brain. Though very nearly complete, the opercula fail in
most cases to entirely overlap the central lobe (insula).

The cerebellum is fully overlapped by the occipital poles of the
hemispheres. The spinal cord ends at the level of the first or
second lumbar vertebra (Ballantyne).

In considering the anatomy of the neck and trunk, it is to be
remembered that the normal position of the infant is one in which

1 Gonner, Zeitsclir. fiir Geburtshilfe und Gynfikologie. Bd xxxm. p. i.

CHAP. VIl]

HUMAN EMBRYOLOGY

163

the spine is flexed, so that when this attitude is exchanged for
that of extension, in which comparisons with the adult form are

Levels of the Viscera, etc., in a Foetus
at the 9th month.

Epiglottis.
Hyoid bone.

Cricoid.

Isthmus of Thyroid.
Oesophagus inclines to left.
Manubrium.
Coracoid
Acromion.

Upper limit Aortic arch.
Bifurcation of Trachea. Thymus. -

Aorta reaches spine. I
Heart base.
Ensiform cartilage.

Spleen.

Central tendon of Diaphragm. Heartapex.
Spleen. Oesophagus pierces Diaphragm.

Spleen.

Pylorus.

Pancreas. Termination of Spinal Cord.

Duodenum crosses Spine.
Aorta divides into Iliac Arteries.

Lowest limit of Peritoneum on Rectum.

Vertebrae.

C I

• II

• Ml

• IV

• V

• VI

• VIl

Thi

• II

• III

• IV

• V

• VI

• VIl

• VIII

• IX

. X

• XI

. XII

L I

• II

• III

• IV

• V

S 1

• II

• III

• IV

• V

C 1

• II

• III

• IV

Levels of the Viscera, etc., in a Foetus
of 4—5 months.

Cricoid.

Isthmus of Thyroid.

Upper limit of Sternum and Thymus.

Upper limit of Aortic arch.

Thymus and Pre- and Meso-sternum.
Aorta reaches spine.

Bifurcation of Trachea. (Manubrium
Lower limit land Thymus.

Heart apex ; upper limit of vault of
Diaphragm.

Ensiform cartilage.

Oesophagus pierces Diaphragm.

Pylorus.

Duodenum crosses Spine.

Termination of Spinal Cord.
Umbilicus.

Aorta divides into Iliac Arteries.

Top of Bladder. Fundus of Uterus

Top of Symphysis pubis.

Fig. 124. Diagrammatic representation of the topographical relations of important
organs to the vertebrae in the foetus at two different epochs.

11—2

164

HUMAN EMBRYOLOGY

[SECT. B

more profitably made, the new condition is (to say the least of it)
anomalous. Bearing this in mind, however, it may be noted that
in the neck the hyoid bone and the larynx are situated higher up
than in the adult, and are thus in a state of transition. Reference
to the diagram (Fig. 124) shews the general position of these
structures with reference to the cervical vertebrae.

Like the cervical organs the thorax is situated nearer the head
in the infant than in the adult. The positions of the manubrium
(Th. I.) and of the central diaphragmatic tendon (disc between
Th. viii. and Th. ix.) shew this. The high position of the latter
is perhaps associated with the lack of development of spinal curves,
but more directly with the conjoined .conditions of uninflated
lungs and relatively large liver. The sulcus pulmonalis on either
side of the spine is shallower than in later life.

In accordance with the position of the thorax the pectoral
limb girdle occupies a high position, the coracoid being above the
level of the first rib, and the clavicle thus being higher at its outer
than its inner end. The whole scapula is about one rib higher
than in adults, and in consequence of the peculiar shape of the
infantile thorax is placed more nearly in the sagittal plane than in
the adult. (Fig. 125.) The sternum is very obliquely placed, the

Fig. 125. Section through the upper thoracic region in a human infant
(at birth): the scapulae are placed laterally, and have not acquired the posterior
position which they occupy in the adult.

lower end projecting anteriorly far beyond the upper. The ribs
are rather more horizontal than in the adult. The heart (in the
foetus) is placed more transversely and horizontally in the thorax
and at a higher level as regards the spine. Its limits will be
seen indicated in the diagram. (Chievitz notes that in the flexed

CHAP. VIl]

HUMAN EMBRYOLOGY

165

intra-uterine position these limits are quite different ; the disc
between D. iy. and D. v. being replaced by D. in., and the disc
between D. vm. and D. ix. being replaced by D. viil). Anteriorly,
a considerable area of the heart uncovered by the lungs is overlain
by the thymus, but the lower part has only the pericardium inter-
vening between it and the sternum. The chief anterior relations of
the heart are thus with the thoracic wall and thymus. The heart is
situated midway between the cephalic and pelvic extremities of
the foetus, but with regard to the spinal column, its central point
is nearer the upper than the lower end of the latter.

The aorta rises as high as the second thoracic vertebra (at
which level the innominate trunk is given off), and reaches the
vertebral column at the level of the fourth thoracic vertebra.
Here the oesophagus passes forwards to the middle line from the
left side, then rather to the right side, and at the level of the 9th
thoracic vertebra the oesophagus pierces the diaphragm. When
the abdomen is opened, the constituents of the umbilical cord
will be seen diverging, the umbilical vein passing upwards, the
urachus downwards, and the hypogastric arteries downwards and
laterally outwards.

The liver (Fig. 126) is relatively great in size, the left lobe

Fig. 126. Section through the abdomen of a human infant (at birth) ; the
lower surface of the section is shewn. There is no duodenal mesentery.

being especially remarkable, for it obscures the stomach. The
stomach is situated on the left side of the body, the pylorus being
immediately in front of the centrum of the first lumbar vertebra.

Left

166

HUMAN EMBRYOLOGY

[SECT. B

The stomach is in relation, anteriorly with the left lobe of the liver,
and posteriorly with the spleen, the tail and body of the pancreas,
the left suprarenal body, and the upper part of the left kidney.

The pancreas has similar relations to those which obtain in
adults, but does not touch the left kidney. The line of mesenteric
attachment is almost horizontal : the caecum is variable in position,
and has by no means always reached its permanent locality in the
iliac fossa, though frequently found here.

The supra-renal bodies are of relatively large size, and the
chief difference between their relations in infant and adult consists
in the fact of their covering more of the surface of the infantile
kidney. The position of the latter with regard to the vertebral
column is indicated in the diagram (cf. Fig. 124); renal lobulation
is still distinct, and there is a difference as regards anatomical
relations from the adult, the embryonic kidney being covered to a
larger extent by the supra-renal bodies. The ureters open into the
bladder at the level of the pelvic brim. The bladder, when not
distended, has the form of a simple tube: when empty, it extends
to about 25 mm. above the symphysis pubis, and when full (in
the new-born infant), may rise above the level of the umbilicus.
Anteriorly no peritoneal pouch separates it from the abdominal
wall : but posteriorly the peritoneum passes down till it comes
into relation with the prostate gland. Behind the bladder there
may be, in addition to the rectum, coils of small intestine, or a
portion of the sigmoid flexure of the colon, or the rectum alone
may be found. In the female the uterus intervenes. In the
pelvis are found the rectum, the prostate gland, and sometimes
a loop of the sigmoid flexure. On the rectum the peritoneum
descends to the level of the fourth sacral vertebra. In female
infants the uterus is an abdominal organ in its upper half or
third, the ovai’ies also lying above the level of the pelvic brim,
but the vagina must be added to the pelvic contents in the female.
The urinary meatus in the female is 10 mm. in front of a perpen-
dicular line drawn from the lower end of the symphysis pubis.

(ii) The topographical anatomy of the foetus at the middle
of intra-uterine life may be partially illustrated by the diagram
submitted for comparison with that of the ninth month foetus
( v . Fig. 124). It will be noticed that the general result of the

CHAP. VII]

HUMAN EMBRYOLOGY

167

observations is to shew that the various organs and structures
occupy levels rather higher at the end of the fourth month than at
the end of the ninth. A special note must be made with regard
to the cerebral hemispheres, which do not overlap the cerebellum
so completely as at the end of foetal life, though in the case
examined they overlapped the mid-brain (cf. Fig. 127) (contrary
to the description of Ballantyne, Foetal Pathology, p. 87). The
cerebral opercula are still rudimentary, leaving the central lobe

NJar)diCjle
-^yoid borje

- -Toroid

cartilage

-Tb^ipus

glared

-.Oesophagus

heart

—Liver

-Lurrjbar portiorj
of vertebral
rprj

pubis

Li gem pled
tooth

Lunpljar

Curvature

_ , 127. Mesial section (A) of a human foetus at about the end of the

oth month oi pregnancy. It is convenient to compare with this the corresponding
section (B) of an adult cynocephalous monkey.

168

HUMAN EMBRYOLOGY

[SECT. B

(Island of Red) freely exposed on the cerebral surface (Fig. 128),
and to judge from Cunningham’s preparation of the head of

Fig. 128. Lateral (A) and ventral (B) aspects of the right cerebral hemisphere
of a foetus of five mouths.

a foetus at the sixth month, the central lobe is covered more by
the frontal than by the parietal bone, owing to the more rapid
development of the frontal element up to this stage. The supra-
callosal part of the hippocampus is distinct (cf. Fig. 129), and
forms the stria of Lancisi.

Conclusions from topographical anatomy. The conclusions
from the topographical anatomy of the foetus will not differ
appreciably whether the earlier or the later stage be considered.

HUMAN EMBRYOLOGY

169

CHAP. VIl]

They amount to the statement that in each case there are differ-
ences in topographical relations from the adult condition, and that
some of these differences constitute resemblances to those obtaining

Strja larjc'isii

Fig. 129. Mesial aspect of the right cerebral hemisphere of a foetus of slightly
greater age than the preceding example.

normally in the lower Primates. For instance, it is remarkable
that while the obliquity of the posterior limb of the Sylvian fissure
(cf. p. 162) is in the ninth month foetus different in degree from
that of the adult human being, this very difference is one that
associates the foetus with the lower Primates. But it is also
noteworthy that the association is with the lower Primates, and
not with the higher members of that order, i.e. it is with the
Cercopithecidae, and not with the Simiidae.

Again, in the incompleteness of the opercular coverings of the
central lobe of the brain, the fifth-month foetus and the ninth-
month foetus, while differing from the human adult, resemble
lower forms, not only of the Primates, but of other Eutherian
orders. In both the stages of foetal life considered the thorax
and the contents of the thoracic and abdominal cavities occupy a
position relatively anterior with regard to the vertebral column
than in the adult human being (cf. Table on p. 170). While thus
differing from the latter, they agree in resembling certain of the

Table from Cunningham Memoir IT. (D. J. Cunningham).

170

HUMAN EMBRYOLOGY

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General note on the foregoing table.

The orang-utan and human foetus agree in differing from adult human beings in respect of the positions of the Larynx
(as judged by the Epiglottis, the Cricoid, and the Tracheal Bifurcation ; v. supra), of the Heart (as judged by its
lower margin; v. supra) and of the Duodenum, all being placed nearer the head in the former than in adult man.
The evidence from the sections of the Chimpanzee and Gibbon is not clear.

CHAP. VII]

HUMAN EMBRYOLOGY

171

lower Primates, especially the Orang-utan, but not, apparently, the
Chimpanzee1.

The difficulty again meets us that the indications are genei’al
and that no special Primate form or forms are indicated as de-
finitely ancestral to Man. But this need cause but little surprise
when it is considered that the modern Primates have all themselves
undergone modifications in the course of their descent from the
common ancestral forms which we lhust expect to have indicated
to us in the recapitulated evolution (ontogeny) of any one of them.

(c) Systematic anatomy of the foetus: (i) The Skull.
A review of the systematic anatomy of the human foetus at
the end of its intra-uterine development may be conveniently
commenced with the study of the skeletal system, beginning
with that of the skull. Of the latter it is essential to recognise
the morphological divisions into cranial and facial portions,
and to note that in several instances, notably in the upper
maxillary, occipital, and temporal bones, several elements are
recognisable which subsequently fuse to form the continuous
masses to which the respective names are severally applied. In
most cases the sutural lines are straight, the adjoining bones being
barely in contact. The bulk of the cranial portion of the skull is
greatly in excess of that of the facial part (and though this is an
anticipation, it must be remarked that in this, perhaps its most
striking feature, the foetal skull departs further from the simian
form than does that of the human adult).

The cranial arc is well developed, and measures nearly four
times the length of the cranial base, a proportion which is sub-
sequently only slightly modified (Ballantyne’s figures are not quite
corroborated by mine: comparison, Ballantyne gives the following;
foetus 3; adult 2'8 to 2'7; while I found the following: foetus 3'9 :
adult 4 L; a chimpanzee 2-2)2. The actual dimensions of the foetal
skull have already been mentioned (cf. the section on topographical
anatomy, p. 162). In form, very considerable variations may be
met with as a result of difficult parturitions, and on the whole there

1 See note on topography, p. 170.

Turner’s figures are (•/. A. and P. Vol. xxxv.) : 20 s Australians 2-7, 20 J Scots
2-8, a gorilla 1*9, a chimpanzee 1*7.

172

HUMAN EMBRYOLOGY

[SECT. B

seems fairly distinct evidence that antero-posterior elongation is
usually produced, though this is usually transitory (cf. Gonner).

When the foetal skull is viewed from above (Fig. 130), the follow-
ing points are to be noticed: the frontal element is smaller than in

Fig. 130. The skull of a foetus at the ninth month, viewed in norma verticalis.

the adult; muscular ridges are absent; the parietal eminences are
very outstanding; and the zygomatic arches are not visible (the
skull is cryptozygous). Turning to the facial portion of the skull
(Fig. 131), the lack of prognathism owing to the small size of the

Fig. 131. The skull of a foetus at the ninth month, viewed in norma lateralis.

upper maxilla (the antrum is small also) is noticeable , the piohle
is flattened, partly owing to the flatness of the nasal bones. The
mastoid process is not yet developed and the tympanic bone is
a shallow, imperfect annulus. The alisphenoid does not extend far

HUMAN EMBRYOLOGY

173

CHAP. Vll]

upwards, and the ascending ramus of the mandible is characteris-
tically short. Viewed from in front, a well-rounded transverse
cranial arc is seen : but the facial skeleton is narrow in comparison
with the broad appearance of the face when covered by the soft
tissues. The interorbital space is wider than in adults according
to Blind 1. The last-mentioned author’s statements that the frontal
ends of the nasal bones are usually narrower in proportion to their
lower ends in the new-born, must be received with caution : in a
certain number of cases such narrowing is marked (the shape then
being comparable to that in the Gorilla, though Blind erroneously
compares it to that of the Orang-utan): again, the upper and
lower diameters may be equal, and then confer an appearance
designated the Hylobates type (Blind). The inferior nasal margins
are quite indistinct (Prenasal grooves 22 °/0, Blind). As regards
the nasal aperture, very exaggerated platyrrhiny, i.e. great width
as compared with height is the rule (index from 7 9 to 50 ; the mean
being 62‘2, Blind). On the facial surface the premaxilla has
already fused with the maxillla.

Viewed from below, the palate presents an hypsiloid (U-shaped)
contour; the spheno- maxillary fissure is wide; the glenoid fossa
shallow ; the anterior lacerate foramen widely open ; and there is
marked projection of the occipital end of the skull beyond the
foramen magnum, which is therefore central in position. Viewed
posteriorly, the cranial contour is often nearly circular, and the
divisions of the occipital bone are seen. The flatness of the
condyles results in their being overshadowed by the squamous part
of the bone. As regards the endocranium, the presence of the
fioccular fossa beneath the superior semicircular canal is to be noted.
There is a suture — the petro-squamous — crossing the roof of the
tympanic cavity.

The vertebral column. In the vertebral column a striking
character is the mobility which enables the foetus to adapt itself
to its confined surroundings: at the same time this mobility and
flexibility render an exact estimate of the characters of the
curvatures of the column a matter of great difficulty. It must be
admitted that the statement (Ballantyne, op. cit. p. 106) is justified,
which reduces the curvatures to two, both concave forwards, and

1 Op. cit. v. p. 157 supra.

174

HUMAN EMBRYOLOGY

[SECT. B

separated by the prominence of the upper sacral margin1. The
cervical portion is relatively to the lumbar portion longer than in
the adult (cervical 18%; thoracic 40%; lumbar 225; sacro-
coccygeal 19%). Macalister ( Human Anatomy, pp. 114, 130)
makes two statements regarding these proportions. Thus in one
connection the proportions (per cent.) are stated to be C. 18, Th. 45,
LS. 37, and a few pages later we find the same proportions stated
as C. 21, Th. 39, LS. 39, in both cases in the new-born infant. The
inference is that the range of individual variation is extensive.
For adults, the percentages given by Macalister ai’e C. 16, Th. 40
for males (39 for females), L. 25, S. 19.

The anterior arch of the atlas is still cartilaginous, and the
spine of the seventh vertebra not yet specially prominent.

The vertebral centra in the lumbar region have not yet attained
the characteristic breadth seen in the adult bones. As regards
the sacrum however there seems little doubt but that it presents
its characteristic of breadth from the fourth month of foetal life
(Thomson).

The ribs are rather more horizontal than in the adult ( v . supra,
page 164); the section of the thorax below the axillae is shewn to
be ndarly circular by the high figure representative of the thoracic
index (the percentage relation of the antero-posterior and the
transverse diameters), and this constitutes a quadrupedal, if not
a definitely simian resemblance.

In this connection the foetus must be distinguished from the
new-born infant, for the inflation of the lungs with air will
naturally react to some extent on the form of the thoracic cage.

The sternum is flattened, and in this respect does not differ
from that of the adult. The subcostal angle is said to be more
open (100° than in the adult, 67° to 80°).

Upper limb girdle. The scapula has much the same form as in
the adult, though owing to the softness of its substance in the

1 Balandin (Virchow's Archiv, 1873), excepts the cervical region, which he
describes as straight. Macalister ( Human Anatomy, p. 129) makes the following
statement. “The primary curve is the dorsal curve of accommodation, concave
forwards, the remains of the primitive embryonic curve, and present from the earliest
period. The sacral curve is also a curve of accommodation for the pelvic viscera,
and appears about the fifth month of foetal life.” But Cunningham shews that
the sacral curve appears before the fifth month, v. infra p. 182, footnote 1.

CHAP. VII]

HUMAN EMBRYOLOGY

175

foetus, exact comparative measurements are not easy to make.
Judged by the scapular index, its proportions are certainly different
from those obtaining in the adult, and constitute a condition
resembling those found in the lower Primates and quadrupedal
mammals.

Lower limb girdle. The sacrum (cf. Fig. 132) has been
already mentioned : its anterior surface is almost plane and the
sacral alae are incompletely developed, so that the appearance of
the bone is elongated. Nevertheless, Thomson states that accurate
measurements shew that this appearance is misleading, and that

^8* 132. The os innominatum (A ventral aDd B side view) and sacrum
(C ventral and D side view) of a foetus at the ninth month.

176

HUMAN EMBRYOLOGY

[SECT. B

the real increase in width is provided for chiefly by the growth of
the posterior parts of the iliac bones.

The ilia (cl. Fig. 132) are much splayed (as in Simiidae)
and anteriorly the iliac fossae are scarcely recognisable. The
proportions ol the pelvic brim have been carefully investigated
by Thomson1, who states that the commonly-accepted account
(which assigns a greater length to the sagittal than to the
transverse diameter), is incorrect, the reverse being the case, so
that the proportions are similar to those which obtain in the adult
pelvis, and different from those of Simiidae and most lower
Primates and Eutheria.

Ballantyne’s results do not altogether confirm these, so that the
proportion is probably a variable one. It seems established that
sexual differences in pelvic form already exist, even as early as
the fourth month of foetal life, that the male pelvic cavity tapers
downwards more suddenly, that the ischial spines are more
inverted (12 mm. inter-ischial diameter in males, 14 mm. in
females, at the ninth month), and that the male sub-pubic angle
(50°) is more acute than that of the female.

Skeleton of the limbs. In the skeleton of the lower limb the
angle between the neck and shaft of the femur is greater (160°)
than in adult life (125°), the foetal condition thus being the
further removed from the quadrupedal one : and that the angle at
which the neck of the astragalus is set is smaller than in later
life, and consequently suggestive of the simian condition2.

A special extension of the upper articular surface of the
astragalus, supposed to be associated with extreme flexion of the
ankle joint, and presumably reminiscent of the squatting position
assumed in ancestral forms, is also to be remarked. The external
malleolus is longer than the internal, thus resembling the adult
malleolus and differing from that of the apes3.

1 Journal of Anat. and Phys. Vol. xxxvm.

2 Bland Sutton, in Morris’s Human Anatomy ; also Shattock, J. A. and P. Vol.
xxrii. and Trans. Path. Soc. xxxv. 1884 ; also Sewell, J. A. and P. Vol. xxxvm.
The internal divergence of the astragalar neck is denoted in the infant by an angle
of 30°; in the adult European, of 10° ; in the ancient Egyptian adult, of 18° ; and in
the anthropoid ape, of 27°. Volkov has recently published an important article on
this subject : Bull dc la Soc. d’ Antin', de Paris, 1903.

3 Keith, Human Morphology , p. 315.

CHAP. VIl]

HUMAN EMBRYOLOGY

177

Musculature. Little precise information on this subject is
accessible. Chievitz ( Topographical Anatomy of the Foetus,
Copenhagen, 1899), has described the course of muscle fibres as
being very straight in the foetus just before birth. The fol-
lowing note from Le Double’s Traite des variations du systeme
musculaire (Tome 11. p. 464) is of much importance. “ In young
children the M. semi-membranosus and semi-tendinosus are pro-
longed below the knee as in certain lower members of the
Primates1.”

Nervous system. The cerebral convolutions (cf. Fig. 133)
are slightly less tortuous in the foetus at the ninth month (or
infant at birth) than at later stages, and this is chiefly due to the

nrn.M%/

?Sulcus>
lui^atu s>

'Rarallel,

Sulcus

lr)tVa parietal
Sulcus

(Betptra I

C w r + SulcuS
O. post CCrjt Sup. /

Sylvi orj
fissure. vallecula
Svlv'ius

Fig. 133. The lateral surface of the right cerebral hemisphere of a new-born
infant.

later development of small secondary sulci which complicate, but
do not essentially modify the pre-existing arrangement. With
regard to particular features, the general arrangement is so similar
to that obtaining in the brains of adults, that the search for
distinctive features is a somewhat minute one. All the character-
istic fissures and sulci of the adult cerebrum are present ; the
rh inencephalon is as much reduced as in the adult brain : the

D. M.

1 Fascial extension is probably indicated. W.L.H.D.

178

HUMAN EMBRYOLOGY

[SECT. B

Rolandic angle (between the median longitudinal inter-hemispheric
sulcus and the central sulcus) is not appreciably different from that
of the adult brain. With regard to the Sylvian region and fissure,
it is to be noticed that the central lobe is not always completely
operculated : the point at which the stem of the Sylvian fissure
reaches the outer surface of the hemisphere is situated relatively
further back in the human infant (and the Catarrhine apes) than
in the human adult. The angle of the Sylvian fissure (i.e. with a
vertical line) is more acute in the infant (and in the Catarrhine
apes) than in the adult. As regards other sulci, it will suffice to
note that the relative length of the sagittal portion of the
intraparietal sulcus is greater in the human foetus than in the
adult (the Simiidae varying in this respect, cf. Cunningham Memoir,
No. VII.). No special remarks can be made with regard to the
peripheral nervous system.

Vascular System, and associated systems and organs. The
heart is (relatively to the body-weight) heavier in the foetus, and
the right ventricular wall (relatively to the left) is thicker. The
foramen ovale is patent, and the valve of the fossa ovalis, the valve
of Vieussens, the Eustachian valve, and the valve of Thebesius are
all distinct. The ductus arteriosus is conspicuous, overshadowing
the pulmonary arteries; the orifice of aperture into the aorta is
guarded by a valve and is peculiar in being oval in form
(Strassmann, quoted by Ballantyne).

The umbilical arteries overshadow in point of size the external,
and indeed the internal iliac vessels. As regards the venous
system, it is to be noted that the vena cava superior is short, and
is vertical in direction. The left innominate vein is nearly
transverse in direction and is covered by the thymus. The latter
body is as broad as it is long, and is usually bilobed, with an
inconstant median lobe. No peculiarities of the lymphatic system
or thoracic duct seem to be known.

Ductless glands. The thyroid body differs in no important
external features from the adult organ. Of the characters of the
spleen but little seems to be known; it has a large area of contact
with the left supra-renal body. The supra-renal bodies are

CHAP. VIl] HUMAN EMBRYOLOGY 179

relatively large (the right larger than the left), they are pyramidal
in shape, and extend as already mentioned, far over the anterior
renal surface.

Respiratory System. The high position occupied by the larynx
has already (p. 170) been noted. The trachea is flattened antero-
posteriorly. The distinctive characters of the lungs depend upon
the lack of inflation in the act of respiration ; the right lung
is larger and heavier than the left. After respiration has been
established, all the pulmonary diameters increase, and there must
be a considerable degree of expansion downwards, to judge by the
amount of space in the lower parts of the thoracic cavity (between
the diaphragm and the parietes) unoccupied by lung before this
occurrence : before respiration too, the lungs have a liver- like
consistency, do not crepitate, little or no blood oozes out under an
incision, and when firmly squeezed under water, they yield no
air-bubbles (Ballantyne). But these phenomena do not essentially
affect morphological comparisons. No lobus azygos impar is seen.

Alimentary system. The stomach is small and more cylindri-
cally elongated than in the adult ; the lesser curvature is directed

Fig. 134.
is shewn.

°T

Caudate

• , . Fibsure^ lobe

'^O'jrjd : Quadrate Call °0 'of""”-

L^rr^t lobe aftPr;Jr°f|ote

The liver of a human foetus at the ninth month ; the inferior surface

lobe

ISuctus veijosus

Spigel

lobe

downwards, first parallel to the side of the vertebral column, and
then transversely to the right across that structure. There is no

12—2

180

HUMAN EMBRYOLOGY

[SECT. B

vestige of a duodenal mesentery, so. that the permanent human
condition has already been attained ; the vermiform appendix
(cf. Fig. 135) is present. The ascending colon has no meso-colon,
the sigmoid flexure (omega-loop) is distinct, and the rectum is
straighter in direction, and thus more simian, than in the adult.

The Liver. (Fig. 134.) The large size of the left lobe of the
liver has already been noticed. Passing over the various anatomical
relations of the organ, it is to be noticed that there is no trace or
suggestion of subdivision of the left lobe ; on the inferior surface
of the right lobe however, certain small fissures may occur, which
are not seen in adult livers; suggest the fissured condition of
this part of the liver in gorilla (Thomson)1.

Genito-urinary system. The kidney (which shews traces of
lobulation) is found on section to
possess several pyramids; it thus re-
sembles the adult organ, and differs
from the kidneys of the lower Simiidae
and Anthropoidea. The bladder is
somewhat tubular in form. In the
male the prostate is distinct; the
testicles are in the scrotum. In the
female, the cervix uteri is relatively
thicker and longer than the corpus,
and the rugae may be prolonged to the
fundus : rugae may also be seen on
the vaginal aspect of the cervix : the
os is sometimes patent : the Fallopian
tubes are sinuous, the ovaries lie
above the pelvic brim, and are ellip-
tical, shewing many follicles on section.

The vagina is relatively long, vertical jrjg 135, Caecum, with vermi-
in its upper part and turning only ‘°°tm

slightly forwards at its lower end.

Thus the female organs of generation differ markedly in the foetus
at nine months from those of the sexually mature individual, but

1 J. A. and P. Vol. xxxiii.

CHAP. VIl]

HUMAN EMBRYOLOGY

181

with the exception of the vagina, none provides distinct evidence
of simian resemblance.

Systematic Anatomy of the human foetus : (ii) The

skeleton. The skull. (Cf. Figs. 136, 137.) The spaces between
the several cranial bones are widely open ; ossification has
commenced in the cartilage of the auditory capsule. The post-
orbital wall is not yet fully formed, owing to the non-development of
the orbital portion of the alisphenoid, and the adjacent part of the
malar bone. The lacrymal bones are relatively large, as compared

Fig- 136. Fig. 137.

fig- 136. Cranium of a human foetus at about the fifth month, viewed in
norma verticalis.

Fig. 137. Cranium and mandible of a human foetus at about the fifth month,
viewed in norma lateralis.

with later stages. The alveolar portion of the maxilla is practically
non-existent. The mandibular symphysis is unclosed, there is
practically no distinction into body and ascending ramus, and
remnants of Meckel’s cartilage are distinctly visible. The foramen
magnum is situated on the inferior aspect, not merely on the
posterior surface, of the skull. In the nasal fossa, as many as six
turbinated bones are recognisable. There is thus a resemblance
to the crania of the Simiidae.

The vertebral column. Throughout the whole length of the
column the neural arches have just closed: ossific centres are

182

HUMAN EMBRYOLOGY

[SECT. B

seen in the centrum and in the odontoid process of the axis
vertebra. The lateral parts of the sacrum are still cartilaginous,
but according to Thomson, this segment is relatively as broad as
in the adult. The vertebral column (cf. Fig. 138) being even more
flexible than at the ninth month, the only constant curves are a
cervico-thoracico-lumbar and the sacral curve1. The thorax
presents a circular appearance in section, the sagittal and
transverse diameters being nearly equal.

iqa^diGle
)-)yoi d borje
■Toroid cartilage

Oesophagus

Heart

A'-i/J. Lun-jbar portiorj

o| ve.r1e.ljr a I
Colurprj

»**9 'Recturr;

Bladder

■S^n^p^sis puUis

Fig. 138. Mesial section of a human foetus at about the fifth month of
pregnancy.

1 Cunningham Memoir ii. p. 76, Fig. D. Embryo of 46 mm.

HUMAN EMBRYOLOGY

183

CHAP. VI i]

The skeleton of the limbs. The clavicle is relatively large (and
herein is a simian resemblance) differing thus slightly from that
of the ninth month foetus and the adult. The scapula is but
partly ossified. The proportion of scapular breadth to length is
about 80 °/0 (at 4| months: at the 4th month it is 84-6 °/o = scapular
index). The olecranon fossa is rudimentary, and the diaphyses
of the shafts of the limb bones only are ossified. The os centrale
has already joined the os radiale carpi. The pelvis is fairly wide
in appearance, but the brim is variable in proportions owing to the
soft nature of the pubis. The ilia and ischia are partly ossified,
and according to Thomson, sexual differences are already distin-
guishable.

The femoral diaphysis has a slight convexity forwards and in
the early part of the third month is almost equalled in length by
that of the tibia. The fibular diaphysis extends lower than the
tibial one but no definite description of the comparative sizes of
the malleoli is possible at this epoch, despite the (quoted) account
given by Keith1.

Both in hand and foot, the ossific centres in metacarpus,
metatarsus and phalanges stand out in striking contrast to the
comparatively soft-tissued carpus and tarsus.

Musculature. Judging from the figures published by Lewis in
the American Journal of Anatomy (Yol. I.), the muscular attach-
ments appear, at an even earlier stage than that considered here, to
have assumed their definite and permanent characters. The special
case of the tendon of the long head of the M. biceps humeri must
be particularly mentioned. At the sixth month, this tendon has
sunk into the capsule of the shoulder joint (to which it was at first
external) and is enclosed with a special envelope derived from the
joint synovial membrane (cf. Macalister, Text-book of Human
Anatomy, p. 286). The case of the M. flexor longus pollicis is of
interest also. Lewis (op. cit. supra) states that in the human
embryo, this muscle has early acquired its independence of the
general deep flexor mass of muscle : nevertheless the drawing in
Fig. C, Plate II. of the article referred to, strongly suggests the
community and fusion of the long flexor of the thumb with the

1 Human Morphology , p. 315.

HUMAN EMBRYOLOGY

[SECT. B

long flexor muscles of the other digits at the epoch in question,
viz. about the 7th week.

The central nervous system. The limits of the rhinence-
phalon (Fig. 139) on the ventral surface are quite distinct, and
the olfactory nerve is relatively large and stout ; bending sharply
outwards at its posterior end and close to the central lobe (insula),
it may now be described as an olfactory tract which is continuous
with the region of the temporal lobe subsequently recognisable as
the uncus. The cerebral hemispheres are characteristically devoid

CHAP. VIl] HUMAN EMBRYOLOGY 185

of sulci1, especially on their cranial aspect : on the mesial surface
there may be distinguished, the hippocampal fissure, the calcarine
and less constantly the internal parieto-occipital sulci. The Sylvian
opercula are quite rudimentary and bound a widely open Sylvian
vallecula or fossa. The occipital extent of the hemispheres is far
from complete, and the corpus callosum is distinct, though also
incomplete in backward extent. (Some discrepancy as to this exists
in the several accounts; cf. especially Kollmann2, Fig. 322 ; and
Minot3, Fig. 392, both from Marchand).

Transverse grooves are beginning to appear on the surface
of the cerebellum.

Vascular, respiratory, alimentary and genito-urinary systems.
In position, the heart is more mesial than at later stages, the
inter-ventricular septum has already been long closed. The thy-
roidal acini are in places still solid masses of cells. The thymus
and supra- renal bodies are relatively much developed in point
of size, but the pituitary body is not conspicuous in this respect.
Apart from topographical relations, there is little to note in the
respiratory system. There is a rudimentary lobus azygos impar
at the root of the right lung and the correspondence of the upper
lobes of the two lungs has been pointed out by Minot3, p. 776.

1 The fissures called “transitory” seem to be proved to owe their origin to
decomposition and to the uneven action of the preservative fluid. Mali’s article in
the Am. Journal of Anat. (Vol. xi. p. 333) gives the most recent literature. Genuine
sulci seem to be equally deficient on the cerebral surface of the foetus of Gorilla at
a corresponding epoch. Only one specimen is however known, viz. that in the
Zoological Museum of the University at Cambridge. The nature of the causation
of the transitory fissures was still under discussion in April 1904, at the meeting of
the German Anatomical Society at Jena, and in a work published in the same year,
Professor His shewed that he had not yet relinquished entirely a belief in the view
that these are veritable fissures and not artefacts.

It remains to indicate a point of interest concerning the fissura perpendicularis
externa (Bischoff). This fissure or sulcus is of common occurrence in the brain of
the foetus at about the fourth month ; corresponding, as it does in position, to the
“ape-fissure” of the brains of Simiidae and other Primates, its appearance was
thought to mark the simian epoch in the development of the human brain, and its
subsequent disappearance claimed as a sign that the epoch in question had been
passed. But Elliott Smith has shewn that the sulcus is really due to the imprint
of the posterior margin of the parietal bone. (Cf. Anat. Am. Bd xxiv. No. 8.)

2 Fntwick. des Memchen.

3 Human Embryology.

186

HUMAN EMBRYOLOGY

[SECT. B

The tonsils are just apparent, and muscle fibres are being
differentiated in the stomach wall. The vermiform appendix
(Fig. 140) is quite distinct, and by the commencement of the
fifth month has been seen in the iliac fossa. (The sigmoid
flexure is quite clearly differentiated also and the rectum pursues
a straight course.) The liver (Fig. 141) is very large, and its
left lobe extends far enough across the abdomen to touch the
spleen : but neither right nor left lobes are subdivided in the

Fig. 140. Right lateral aspect of the abdomen of a human foetus of about
5 months; the caecum with its appendix is exposed; the final position ol both will
be lower and some circumduction of the latter may occur in later stages.

(Catarrhine) ape-like fashion. Several papillae project into the
pelvis of the kidney, which is very large and lobulated. The testes
are abdominal in position, the gubernaculum is distinct, and the

CHAP. VIl]

HUMAN EMBRYOLOGY

187

Caudate lobe.

Trace of

d l V l S 1 0 13

’of riah)t
lobe

Caudate lobe

Trace* of

cWi Sion .
of viqht
lobe

Fig. 141. Livers of two human foetuses at about the 5th month. In
neither is the caudate lobe so distinct as in the Cercopithecidae, nor is the quadrate
lobe yet detached from the (parent) right lobe. (A is a spirit specimen, B has
been preserved in Muller’s fluid and shews the true form of the organ.)

HUMAN EMBRYOLOGY

188

[SECT. B

prostate can be identified. In the female, the lumen of the
vagina is closed.

The enamel-organ of the deciduous teeth is now differentiated.

Conclusions from the study of foetal systematic anatomy
at the ninth month. When the general characters of this, the
most advanced foetal stage in Man, are reviewed with the object
of examining evidence bearing upon the question of Man’s more
immediate ancestry, it seems as though the observations may be
ax-ranged in tln*ee groups. First of all, there ai-e to be noticed
characters, such as the relatively large size of the liver, of the
hypogastric arteries, or of the fontanelles, which appear to be
quite irrelevant ; these are in fact, conditions associated with, and
determined by the particular and peculiar mode of development
in the higher Eutheria, and therefore they may be expected to
obtain in all these animals alike1. Secondly, there are a number
of characters, such as the great size of the head and of th'e cere-
brum, which are related to the specific and peculiar characters of
the Hominidae, and which might well be expected to be so im-
pressed in their organization as to appear, prematurely, so to
speak, in his individual development, just as in all Amniota the
brain is early differentated, grows with precocious energy, and
rapidly attains an apparently disproportionate size. The estab-
lishment of these two categories leads to the recognition of the
fact that a vei-y considei-able number of the chai-acters of the
ninth-month foetus cannot be directly applied to the elucidation
of the problem of human descent, and that indeed they must be
eliminated with gi-eat care. They lead however to the conclusion
that at this epoch, human peculiarities are pei-fectly patent and
strongly imprinted.

But when due allowance has been made for the occurrence of
such characteristics, there remains a residue of observations which
may be collected and associated in a category of pithecoid affinities.
The flatness of the nose, the imperfect power of opposition of the
pollex (shewn by the mode of gx-asp in the new-born infant), the
straighter lumbar column, the flattened sacrum, the imperfectly
extensible hip and knee, the proportionately long upper limb, the

1 See note on page 189.

CHAP. VIl]

HUMAN EMBRYOLOGY

189

s » s i * I5

P cs ® g 'H 2

P P

'g 'O

•S 'o £,'3 3
qT~ A ^ jj“

190

HUMAN EMBRYOLOGY

[SECT. B

incurved feet (and, in the female, the straight vagina), may be
mentioned as features of this kind, which definitely support the
theory of an ancestry inclusive of ape-like forms. Further,
though the evidence is not yet so complete as could be wished,
there is no reasonable doubt but that the associations are with the
Simiidae rather than with their lower congeners among the
Primates, due account being taken of resemblances first to one,
then to another of the lowlier forms in that Order. Among the
Simiidae, it is difficult to choose between the three larger forms,
but, again upon the whole, the associations with the Chimpanzee
are maintained longer than with the remaining examples.

And upon these considerations the view is based, that of living
animals, this (the Chimpanzee) represents, not necessarily very
closely, but on the whole more nearly than any other, that com-
paratively late human ancestor, which were it still in existence in
an unmodified form, we should be induced to associate morpho-
logically with the Family Simiidae, while excluding it from the
Family Hominidae.

Conclusions from systematic anatomy at the fifth month.

When we pass to the earlier stage of foetal existence, the con-
ditions are somewhat altered as regards our estimate of the
evidence. For in passing to the middle of intra-uterine de-
velopment, we have retraced the individual back to a stage at
which the group of characters expressive of the mechanical and
physiological conditions of embryological growth are more promi-
nent than at the later epoch. Examples of such characters have
already been given, to which may be added for the sake of
illustration, such phenomena as the cartilaginous condition ol
the tarsus and carpus, and the intra-abdominal position of the
testes.

Combined with these, the specific human characters are
asserting themselves, and combined with those of the preceding
group, leave but a very small residue of features upon which
to base conclusions as to the exact phylogenetic path of Man
through the Primate phase. So small a minority indeed is it,
that we are at a loss for evidence to enable us to assign to Man
ancestors represented by any forms taken from the Primates im-

CHAP. VIl]

HUMAN EMBRYOLOGY

191

mediately below the Simiidae. A more detailed exposition and
enumeration of details, and a more subtle analysis of their import,
may yield this information at a later date, but for the moment we
have to admit that the problem remains unsolved.

Examination of the human foetus at the mid-term of its
development having provided an imperfect response to our
enquiry, it is but natural to pass still further back, and to take
up the question of the very earliest stages of embryology as
affecting Man, and to review, however briefly, the available
information, which will therefore form the subject of the next
chapter.

CHAPTER VIII.

HUMAN EMBRYOLOGY (. oont .).

In entering upon the consideration of the early embryology of
Man and his nearest allies, it may be remarked again (cf. Chapter I.
page I I ) by way of introduction, that upon the general similarity
in the embryological processes in Man and other Eutheria, have been
based arguments as to the community of origin of these mammalian
forms. One of the early triumphs of embryological investigations
was the demonstration that the process of development consists (in
its early stages) in the evolution of a multicellular from an unicel-
lular organism. In the unicellular condition, the several mammals
closely resemble each other, the chief differences at present
demonstrable being those of size. As the process of development
advances, the various forms are found to resemble each other for a
longer or shorter period according as they are more or less nearly
related.

Passing now to a later epoch in the history of embryological
discovery, we may refer to the state of that science in so far as it
bears upon the development of the higher Eutheria, at the time
(1863) when Huxley was delivering the course of lectures on “Man’s
Place in Nature.” At that date, Huxley was able to state, that for
30 years past it had been known that the human embryo pursued
a path in development which ran parallel to, if it did not coincide
with, that for instance taken by the embryo of a dog, during
a very considerable period in embryological history. Facts and
illustrations were adduced in support of this statement.

Not only is the human embryo similar in appearance to those
of other Eutheria, but much general similarity obtains in respect

HUMAN EMBRYOLOGY

193

CHAP. Vlll]

of the conformation and structure of the embryonic tissues and
membranes of both. And it might well appear that where such
similarity obtains between the Hominidae and Eutheria of an
Order (the Carnivora) far removed from the Order Primates, it
would be futile to seek for evidence of the more intimate relations
of Man with animals included within the latter Order. In fact we
might presume that the evidence, if any were forthcoming, would
be of the vaguest description. And yet, even at the time at which
Huxley wrote, indications that such a search might not prove
altogether fruitless were to some extent forthcoming, and with the
progress of embryological investigation a body of facts of not
inconsiderable amount has gradually been brought to bear upon
the point at issue, as to the closeness of the relation between Man
and the higher Primates.

Another suggestive point remains to be dealt with. It is
admitted that although in the comparison of the bodies of the
developing human individual and the carnivore, similarity can be
traced for a considerable distance, yet divergence in certain adjuncts
occurs, and is evident even in comparatively early foetal stages.
Huxley (in 1863) pointed out three morphological features in
which this difference was to be observed. These points are:

(1) the form (in its later stages) of the yolk-sac whence the
early embryo draws its nourishment.

(2) the form of the allantois, a protrusion from the embryo
which is intimately connected with the outgrowing blood-vessels ;
the latter spring from the body of the embryo, and are directed
towards the maternal tissues, which they penetrate, and so provide
for the nourishment of the embyro after the yolk-sac has fulfilled
its functions.

(3) the form and disposition of the placenta, the organ in
which the interchange of material between the maternal organism
and the embryo takes place.

In respect then of the outward appearance and the microscopical
structure of these organs, the human embryo is found to possess
a distinctive character, which differentiates it from the dog at a
corresponding stage. But the important point brought out by
Huxley is, that precisely where the human embryo differs from the

D. M.

194

HUMAN EMBRYOLOGY

[SECT. B

carnivore, there it is to be found in agreement with the apes. In
the same respects too, the human organism finds itself associated
with the higher apes, and differentiated (just as it is from Carnivora)
from the lower Primates, from Cheiroptera, Ungulata and other
Eutheiian Orders. Phis point being established, we may proceed
to investigate the nature and the results of some of the more
recent embryological researches on human and simian organisms.

h or present purposes, embryology may be conveniently divided
into phases which may be entitled chapters, although in reality
no hard and fast lines of demarcation are to be drawn, and the
distinction of the several phases is made purely and simply for
convenience in dealing with a complicated history. With this
premise, it is proposed to deal with the subject as far as there are
concerned :

(1) The early history of the events accessible to observation
and immediately subsequent to the fertilization of the ovum.

(2) I he history of the formation of that characteristic and
protective covering of the embryo known as the amnion.

(3) The history of the formation and the relations of the
embryonic yolk-sac.

(4) The manner of attachment of the embryo to the maternal
tissues, and the mode of nutrition.

Chapter I. The early history of the events immediately sub-
sequent to the fertilization of the human ovum. During the last
forty years an immense number of observations has been added to
the store from which Huxley was able to draw. Huxley’s descrip-
tion of the changes which the spherical ovum undex-goes sub-
sequently to fertilization (changes which consist in an equatorial
fission of the sphere into hemispheres, each of which assumes a
spherical form and again divides, the process continuing till
the single original sphere is replaced by a mulberry-like body
(morula), was based upon observations on other mammals than
Man, for no observation had been possible in the case of the human
ovum. So great are the difficulties in the way of observation, that
absolute facts are still lacking as regards the exact details of the
history of the human ovum immediately after fertilization, and
there is a similar lacuna of observations as regards the higher xipes.

HUMAN EMBRYOLOGY

195

CHAP. VIII]

Thus it is, that what we have termed Chapter I. of the embryo-
logical history of the higher Primates remains still to be written.

When we turn to Chapter II. (the history of the formation of
the amniotic covering of the embryo “amnion ), we find that while
abundant observations are now available as regards this subject in
the embryology of such animals as the Rabbit, Mouse, or Hedgehog
(to consider the Eutherian mammals only), yet in respect of the
embryos of the higher Primates, information, for the same reasons
as are responsible for the vagueness of the earlier events, is here
lacking almost entirely. For in all but a very few of the early
embryos of Man that have been hitherto available for examination
the amniotic covering has been found already completely1 formed
(cf. Figs. 142 and 143). In the exceptions to this remark, of which
about eight have been recorded in the space of half-a-century, no
embryo was to be seen, and the state of preservation of these
specimens was probably not satisfactory as a basis for reliable
information.

EMBRYO

ALLANTOIC

DIVERTICULUM

Fig. 142. Diagram of the appearance in section of an early human ovum (from
Kollman, after Graf v. Spee). The amnion is complete.

Disappointing though this may be, there are nevertheless
observations which throw some light on this part of the history of
the embryo. For from the comparison of the Old World monkeys
and the higher apes with Man in respect of early development, the
close similarity if not the identity of these processes is fully
established (notably by the researches of the late Professor Selenka).

1 This is the case in a human ovum, the estimated age of which is seven days.
(Cf. Peters; quoted by Robinson, J. A. aiul P., July, 1904.)

13—2

Fig. 143. Diagram (modified from Selenka) of the section through an early
ovum of a Semnopithecus monkey, and the adjacent uterine tissues. A general
similarity to the arrangement which obtains in the human ovum is here seen.
A. Decidual cells of uterine mucous membrane. B. Deeper decidual cells.
C. Maternal capillary vessels opening into the intervillous spaces. D. Eemnant
of the wall of a maternal capillary vessel. E. Foetal ectoderm (chorionic).
E'. Foetal ectoderm (non-chorionic). M. Foetal mesoderm. II, Foetal
entoderm. S. Syncytium. As in Fig. 142, the amnion is complete.

CHAP. VIII]

HUMAN EMBRYOLOGY

197

And as regards the apes, observation leads to the supposition that
their early embryonic history is characterised by a very remarkable
process affecting the spherical vesicle (blastoderm) into which the
morula or mulberry-like mass of cells is transformed. In the first
place, this vesicle at a very early period acquires its attachment to
the maternal tissues, and presumably takes its nourishment from
these, instead of prolonging the period of nutrition from its own
original yolk material. Such precocity in attachment to the
maternal tissues constitutes a mark of distinction shared by apes
and a comparatively small number of mammals.

In the second place, the blastodermic vesicle subsequently
appears to undergo a process termed “inversion,” by which one part
of its surface is depressed and invaginated into the other part, the
form thus changing from that of a hollow sphere to that of a cup-
shaped hemisphere with double walls. (Cf. Fig. 144.)

Sphere

Fig. 144. Diagram representing the process of inversion of the germinal
layers.

The process of “inversion” has been clearly observed in such
rodent animals as rats and mice, but its progress has not been
actually noticed in the apes, though Selenka has figured cases
which suggest its occurrence most strongly; even in the Hominidae
“inversion” was suspected as long ago as 1889 by Graf von Spee :
nine years later Selenka’s observations lent great support to his view:
and finally in 1900, Mall (cf. Fig. 145) described a human embryo
whose appearance, it is believed, leaves no doubt as to the occur-
rence of this process in Man. The phenomenon of inversion confers
on the embryos of the Hominidae and higher Primates a mark of
distinction shared, as stated above, by a few mammals only.

Into the details of the phenomena it would be impossible now
to enter, but it will suffice to note, that in this, the second chapter

198

HUMAN EMBRYOLOGY

[SECT. B

of embryonic development, there is a remarkable conformation of
the suspected similarity of the events in the apes and Man. And
at the same time it is to be remarked that where, as in these
Primates, “ inversion ” occurs, it follows that the amnion owes its

Ail.

Fig. 145. Diagram (adapted from Mall’s figure) of an early human embryo in
which evidence of inversion of the germinal layers may be found. E. Ectoderm

(chorionic). E'. Ectoderm (non-chorionie). II. Ectoderm. All. Allantoic

diverticulum.

formation to a process essentially different from that obtaining in
most of the other placentalia, a process which however is described
as occurring in the hedgehog and guinea-pig (Hubrecht), besides
the rodents just mentioned, so that in this respect man does not
stand accompanied by the apes and higher monkeys only1.

1 It appears a matter for surprise that so many writers on embryology during
the last fourteen years should have neglected to discuss the application of Hubrecht’s
description of the formation of the amnion, and the phenomena of 1 ‘ inversion ”
(first described by Selenka in 1883) to the case of Man and his allies. This is the
more remarkable because we note that as early as 1889 Graf v. Spee suggested the
possibility of inversion occurring in human embryology, and if inversion occurs it

CHAP. VIII]

HUMAN EMBRYOLOGY

199

Chapter III. The Yolk-sac. We now come to the chapter which
deals with the early development of the yolk-sac. The importance
attaching to this part of the subject depends upon the fact that in
certain mammals the (in mammals fluid, in Sauropsida solid)
contents of the yolk-sac provide for the nutrition of the embryo
for a very considerable period ; this provision is effected, both by
direct withdrawal of the contents of the yolk-sac, and also through
the agency of the vitelline vessels, which are distributed
abundantly over the surface of the yolk-sac. Now as far as can
be judged of human ova, the essential mode of formation of the
yolk-sac, and its relation as part of the entoderm to the other
important layers (mesoderm and ectoderm), follows the general rule
for mammals. The characteristic difference is met with in the
further development of the sac: in the most primitive mammals
the sac forms a complete lining to the whole of the blastodermic

Fig. 146. Diagram of the human embryo and its coverings, to shew the
proportionate sizes of the allantois and the yolk-sac. (Cf. Kollmann, Entiv. des
Menschen, Fig. 35, p. 79, and Fig. 104, p. 175.)

follows that the amnion is probably formed, not as usually described by uprising
folds which coalesce, but by fission, as described in Hubrecht’s account of this
structure in Insectivora and certain rodents. But if we consult recent works, we
find that while Minot (Human Embryology , p. 286) mentions these suggestions, and
Parker and Haswell (Zoology, Vol. ii. p. 550) give a resinnS of Hubrecht’s work,
yet such authors as Marshall, Kollmann, Gilis, and more recently Keith, either
entirely pass over in silence the work referred to, or only record the titles of the
original papers, without any pronouncement either of acquiescence in, or dissent
from the conclusions formed therein.

200

HUMAN EMBRYOLOGY

[SECT. B

vesicle : a good example of this may be seen in the young rabbit
embiyo (cf. Figs. 146 and 147). But in the higher apes and Man,
such a development is not seen; at no period, apparently, does
the yolk-sac form such a complete lining, and on the contrary it is
in relation with the wall of the blastodermic vesicle for a very
short period and over a small area of surface only1.

Fig. 147. Diagram of a rabbit embryo and its coverings, for comparison with
Fig. 146 ; to shew the proportionate sizes of the allantois and the yolk-sac. Adapted
from van Beneden’s figure as modified by Marshall.

The yolk-sac in Man has thus entirely lost the function ascribed
to it by Osborn (cf. Kollmann, Entwick. des Menschen, p. 169) and
others, in Opossums and other marsupials, of coming into contact
with the uterine walls, and of producing villi which enter the
uterine mucosa, which, being invaded by vitelline capillary vessels,
act as the villi of the placenta act in higher mammals. Nor does
it appear to be the case that in Man, any more than in certain
other higher mammals, the entoderm of the yolk-sac contributes
processes which enter a placenta formed on the embryonic side by
mesodermal allantois (i.e. an allantois composed of mesoderm

1 So far therefore as is known, the human blastodermic vesicle differs from that
of the rabbit in the important respect of the conformation of its wall. For from
His’ description of Reichert’s ovum (cf. Marshall, Vertebrate Embryology , p. 473)
it would appear that in the human blastodermic vesicle the wall consists of ectoderm
only, whereas in the rabbit ectoderm and entoderm combine to form the wall. Cf.
Figs. 146 and 147. But this difference is not generally insisted upon.

HUMAN EMBRYOLOGY

201

CHAP. VIII]

without entoderm) only, so that the entoderm and mesoderm may
share in the formation of the placenta even where the allantois
provides mesoderm only. (Cf. Hughes, Brit. Med. Journal, 1895,
p. 1341.)

On the contrary, the human yolk-sac has a most transitory
nutritive function, and although still capable of recognition in the
placenta at birth, its physiological significance is practically nil
after the first few days of development1.

Chapter IV. Attachment of the ovum. The fourth chapter of
events proposed for consideration deals with the method of attach-
ment of the human ovum to the maternal tissues, and the mode of
nutrition of the embryo. In the first place, there is now evidence
(Leopold’s case quoted by Barlow, Obst. Trans. 1898) that the
ovum is not, as had been previously suggested, implanted upon a
denuded area of the maternal surface (in other words, an area of the
uterus denuded of its mucous membrane). The appearances
described by Peters in a human ovum (seven days after fertilisation)
corroborate this, but as to the details of the process of attachment,
no evidence is provided either by this, or by the earliest Hylobates
embryo described by Selenka2.

Secondly (though this is perhaps arguing in a circle), the
researches of Selenka on the embryos of the higher Primates
shew that, on the contrary, the maternal tissues hypertrophy, the
lining (epithelial) cells of the uterus proliferate and produce
a syncytium, or mass of rapidly developing cells. It is to be
particularly noted that in the lower apes such proliferation and
hypertrophy occur on two aspects of the embryo (with the
subsequent formation of two placental areas3). This occurs as a
rare anomaly in Man, and then provides an exception to the
rule that but one such area of hypertrophy is to be found ; never-
theless it is an anomaly which suggests in the Hominidae a
former similarity to the process which has been retained in the
Apes. Selenka thus regards the syncytium as derived neither
from the chorion-entoderm (Kollmann), nor from the submucous

1 Ballantyne seems to dispute this ; cf. Obst. Trans. Edin. Yol. xxm.

2 Cf. Robinson, J. A. and P. xxxvm., 1904, p. 490.

3 Bee footnote (1) on p. 212.

202

HUMAN EMBRYOLOGY

[SECT. B

uterine decidual connective tissue cells (Minot, Human Embryology,
pp. 13 and 3/5), nor from the foetal ectodei’m (Robinson, Hunterian
Lectures, J. A. and P. Vol. XXXVIII. p. 493), but from the epithelial
lining of the uterus. Into this area of hypertrophied mucous lining
of the uterus the ovum enters, and it would seem to be entirely
enveloped in the spongy mass. From one pole of the ovum, the
ectodermal covering (primitive chorion) is still further projected
in tufts into the maternal tissue, and behind and within these
ectodermal tufts or villi come masses of mesoderm cells, which are
ultimately permeated by blood vessels.

Meanwhile from the portion of the ovum not thus deeply
projected into the maternal tissue the embryo has been developing,
and in the course of time the connection between the embryo and
the projected part of the original blastodermic vesicle is provided
by a solid stalk of mesoderm called the Ventral -stalk, or Haft-stiel,
which in its solidity and precocity of development is characteristic
of the human embryo and the embryos of a few exceptional
mammals, including the Primates (Selenka). Turning back to
what has been called the “deeply-projected part” of the vesicle, it
is found that both this and the adjoining maternal tissue become
vascularised to an extraordinary extent (cf. Fig. 148) on the
embryonic side by the arrival of vessels diverted from the primitive
and transitory yolk-sac system of blood vessels, and on the maternal
side from the uterine capillaries. On the maternal side, the
capillaries work their way in between the cells of the hypertro-
phy ing mucosa, and project in the interstices with a covering of
the thinnest description of endothelial cells ; these are destroyed,
probably by the action of the syncytial cells of the mucosa, and
thenceforward the contents of the maternal capillaries bathe the
projections or villi of the blastodermic vesicle. These villi themselves
being honeycombed with capillary vessels, derived as already
stated from the embryo, provide an approximation of the closest
nature between the blood of the mother and that of the embryo,
the only intervening layers between the two being embryonic in
oi'igin, and consisting (theoretically at least) of the remains of the
embryonic ectoderm (which practically vanishes) and the endo-
thelial coat of the embryonic capillary. The closeness of this
connection, and the degree of the entwinement of the embryonic

Fig. 148. Diagram of an early embyro of Semnopithecus (Cercopithecidae)
(after Selenka), to shew that the “ intervillous ” space is primarily an intercellular
space of the uterine epithelium. A. Decidual cells of uterine mucous membrane.
B. Deeper decidual cells. C. Maternal capillary vessels opening into the
intervillous spaces. D. Remnant of the wall of a maternal capillary vessel.
E. Foetal ectoderm (chorionic). E'. Foetal ectoderm (non-chorionic). M.
Foetal mesoderm. H. Foetal entoderm. S. Syncytium.

204

HUMAN EMBRYOLOGY

[SECT. B

villi and their capillaries, with the maternal mucosa and its blood-
sinuses, constitute peculiarities of the placenta shared by Man and
the apes, distinguishing them from other mammals (in which
the connection of maternal and embryonic derivative structures
is not so close). The two resulting types of placentation are
commonly contrasted as the deciduate and non-deciduate varieties1.

But the nature of the intervening layer of tissue between the
maternal and the embryonic blood, and the destructive action of
certain cells and their reference to the maternal or to the
embryonic organism, have been matters of longstanding discus-
sions, not to say disputes which have only been comparatively
recently composed by the brilliant researches of Selenka. Thus
Duval described the intervening layer in Rodentia (the rabbit) as
consisting of embryonic endothelium (mesoderm) alone, but the pre-
ceding statements are the first dealing specifically with Primates.

Marchand ( Anatomische Hefte, Band XXI. 1903) describes the
histology of some early human ova and their uterine surroundings,
but does not appear certain (of. p. 256, op. cit .) of the source of the
syncytial layer : as regards the general relation of the ovum to the
uterine tissues (the implantation or “ Einlagerung ”), Marchand
{op. cit. p. 262) points out that the ovum sinks into the uterine
decidua basalis; that, like the rodent (guinea-pig) ovum as described
by v. Spec, the embryonic tissues act towards the maternal
structures much as a malignant neoplasm, reminding one of that
variety of growth known to pathologists as Deciduoma malignum.

Robinson {op. cit., cf. p. 201 supra), appears to dissent from
Selenka’s view as to the maternal origin of the syncytium, which
he ascribes to the ectoderm of the foetus. For Robinson, the
foetal tissues therefore play a more important part in the pro-
duction of the placenta, of which they form a larger constituent
than on Selenka’s view. If this is so, opinion as to the nature of
the tissues ruptured and separated with the placenta at birth
must be modified accordingly, as will be indicated in the appro-
priate connection (p. 207).

From Selenka’s researches (cf. Selenka, Menschenaffen, Kapitel
in. Das Ei des Gibbon, also Placentaranlage des Lutung'*, Biol.

1 v. infra, p. 205 ; and footnote (1), p. 209.

2 Lutung ; the native name for a species of Semnopithecus found in Borneo.

HUMAN EMBRYOLOGY

205

CHAP. VIII ]

Gentralblatt, XVIII. No. 15, with Kollman, Entw. p. 164, Fig. 94,
and Leopold, op. ait., cf. p. 201 supra), it would nevertheless appear
that there is the very closest similarity between the process in Man
and in the higher Primates.

The Placenta. Attachment of the ovum, and nutrition of the
early embryo ( continued ). In the chapter descriptive of the Order
Primates it will be noticed that the placenta is enumerated among
the criteria used for distinctive purposes, and indeed to the
characters of this organ as a means of classifying the mammals
possessing it much importance was at one time attached. A brief
note on this subject may therefore not be out of place in this
connection. One of the chief contributions to the comparative
anatomy of the placenta was made by Turner, and the classification
suggested by him was quoted (as recently as 1900), by Kollmann
{Entw. d. Menschen). This classification was as follows :

(1) Deciduata: characterised by the close connection of the
uterine mucous membrane and the placenta foetalis, detachment
of both structures occurring in parturition : ex. Man, Apes and
probably Lemurs.

(2) Demi-deciduata : characterised by the less close con-
nection of the above-mentioned structures, and by a partial
detachment at birth : ex. Carnivora, Insectivora, Proboscidea,
Cetacea, Edentata (Dasypus and Choloepus among the latter).

(3) Indeciduata: characterised by an even less close con-
nection ; ex. Ungulata, such as Ruminants, Swine, Horses, Tapirs,
and also certain Cetacea: while Marsupialia (Metatheria) and
Prototheria were supposed to be implacental. Diagrams now
well-known1 were published in illustration of the various
conditions.

Later research caused a modification of this scheme, for among
the Edentata in particular, the latitude of variation in placental
structure has thrown doubt on the value of this character as a
classificatory criterion.

In 1889 Hubrecht suggested a complete revision of the fore-
going classification, and submitted (as specially antagonistic to

1 Cf. Foster and Balfour, Embryology , Macmillan.

206

HUMAN EMBRYOLOGY

[SECT. B

Turner’s views of the homologies of the several histological strata
involved, and particularly to Turner’s suggestion that in the human
embryo the arborescent villi are invested by prolongations of the
uterine mucous membrane) the following statements :

(1) That in numerous Orders the epithelium of the uterus
entirely disappears over the future area of attachment of the
blastocyst. (But from Leopold’s researches it seems that this
statement does not apply to the human embryo, W.L.H.D.)

(2) That in some (the more primitive) of these Orders, the
lacunary blood-spaces are in contact with the blastocyst before the
appearance of the embryonic area vasculosa. Hubrecht suggested
later that the embryonic epiblast causes absorption of these
maternal tissues ( Proc . Interned. Zool. Congress, 1898).

(3) That the communication between the lacunae and the
maternal vessels is not a mere dilatation of capillary vessels as
described by Turner, but a more complicated process.

(4) That embryonic epiblastic tissue (termed trophoblast)
appears between the villi of the blastocyst and the maternal blood.
Later (in 1898, op. cit.), Hubrecht urged that maternal blood enters
into clefts in the trophoblast, and that, subsequently, embryonic
villi are introduced into these blood-filled clefts, pushing a layer
of trophoblastic epiblast before them.

An essential point in Hubrecht’s work is the indication that
before the establishment of the ordinary placenta the embryo may
receive nutriment from the maternal blood, which enters and
circulates in the clefts or lacunae in the embryonic trophoblast.

It would thus appear that as far as the human embryo is con-
cerned, Hubrecht is inclined to derive the placental tissues more
largely from the embryonic side than from the maternal mucous
membrane, and with regard to this (and particularly to the syncytial
cells), it is to be noted that Turner’s view rather than Hubrecht’s
is supported by the latest observations of Selenka on the Semno-
pithecus pruinosus, observations which are almost certainly
applicable to the human embryo1.

1 Hubrecht also pointed out that among the Primates, the Lemuroidea are non-
deciduate, with the remarkable exception of Tarsius, an animal already in a
somewhat exceptional position as judged by morphology, and which thus finds

CHAP. VIII]

HUMAN EMBRYOLOGY

207

Robinson (op. cit. cf. p. 201 supra ) would presumably support
Hubrecht’s view. But if the placenta is so largely foetal, it becomes
doubtful whether any maternal tissues are ruptured or detached
when the placenta is separated from the uterus. In fact Robinson
suggests that foetal tissue may even remain in utero, there to be
subsequently absorbed. But with this view, the application of
the term “ deciduate ” to these placentae (of the Hominidae and
Simiidae) falls to the ground, for we have just seen that detach-
ment of maternal tissue is a necessary qualification by reason of
the terms of definition laid down. Indeed a revision of the
classification of placental types was seen to be necessary by Strahl ;
Robinson however rejects Strahl’s amended classification, and has
submitted another amendment, with which his name may be
associated, and which is appended. (Cf. p. 210, footnote 1.)

Mode of nutrition. The enquiry into the mode of the earliest
nutrition of the embryo has received a considerable amount of
attention. Selenka shewed twenty years ago that secretions of the
uterine glands apparently nourish the ovum of the Metatheria
(Marsupials); in Rodentia, Insectivora and Cheiroptera this is less
likely to be the case, since the uterine glands early vanish; in
Carnivora and Primates, it is suggested that nutriment is derived
from the uterine lining in this way, but exact information seems
to be lacking, and against this view it may be urged (in spite of
Minot’s statements, op. cit., p. 375) that hypertrophy (not absorption)
seems to be the characteristic of the uterine epithelium. Hubrecht
has suggested another method whereby the early embryo may
derive nourishment (cf. the preceding paragraph), and Ballantyne
( Obstetrical Transactions, Eclin., Vol. xxm.) urges that the vitelline
circulation may also play a part, in addition to possessing the

itself associated with the Anthropoidea, and accordingly among the Deciduata. On
these grounds Hubrecht has attempted to separate Tarsius entirely from the
Lemuroidea, but recent criticism by Dr Elliott Smith, Proc. Linn. Soc. 1903, shews
that this attempt cannot be regarded as successful.

Subsequently, Hubrecht proceeded to shew evidence of blood-formation in the
placenta of Tarsius, and to urge that there may be an actual and absolute com-
munication between the circulatory systems of the maternal and embryonic
organisms. A final pronouncement on this question seems to be still in abeyance,
but its importance as occurring in a placenta so like that of the Hominidae cannot
be ignored.

208

HUMAN EMBRYOLOGY

[SECT. B

ordinary functions attributed to it. The characters of sympodial
human monsters, in which allantoic and therefore “umbilical,” as
contrasted with “vitelline,” vessels are conspicuously absent, are
urged in support of the latter view, as are also cases of Exomphalos,
and observations on Rodentia, Cheiroptera, and Insectivora. Minot
does not support Ballantyne, and the question of a primitive
vitelline placental circulation must be left undecided.

It remains to notice the later character of the placenta, and
its specific features in the Primates.

In the higher members of the
Order including the Hominidae, the
placenta is disc-like in form, and is
termed metadiscoidal (Figs. 149
and 150). In the Lemuroidea (ex-
cept Tarsius and perhaps Dauben-
tonia), the placenta is diffuse; into
the differences between the two
varieties it is not necessary to enter
in detail, but it may be remarked
that the chorionic villi in the An-

thropoidea persist only in thelimited

Fig. 149. Foetus of Hylobates
x x miilleri, about 57mm. in length ; the

area corresponding to the eventual discoid placenta is shewn. (Specimen,
... - , ■ ,, Hose donation, III. Mus. Anat. Gant.)

placental disc, whereas in the

Lemuroidea the villi remain and develop on the whole periphery
of the embryo. Accompanying these differences between the
Anthropoidea and Lemuroidea are others chiefly dependent upon
the development of the allantois.

Fig. 150. Foetus of an Orang-utan, with discoid placenta. (After Stralil.)

HUMAN EMBRYOLOGY

209

CHAP. VIII]

The anthropoid placenta has been termed metadiscoidal in
distinction from the discoidal placenta found in certain lodents
(especially the rabbit). The distinction is stated (Foster and
Balfour, Embryology, p. 358) to depend on the fact that in the
human embryo the allantois spreads over the whole inner surface
of the sub-zonal membrane, whereas the allantois is of limited
extent in the rabbit. Now there are two objections to this state-
ment. In the first place, the subzonal membrane is defined by
Foster and Balfour (p. 346, op. cit.), following Turner, as a compound
of the false-amnion and the wall (entoderm) of the yolk-sac ; but
we are given to understand (cf. His’ interpretation of Reichert s
ovum, and Marshall’s comments, Vertebrate Embryology, p. 476),
that the latter is a comparatively insignificant structure in the
human embryo ; that it does not extend far in the direction of the
wall of the blastodermic vesicle ; and certainly is not comparable
in this respect to the yolk-sac of the rabbit. (Cf. Figs. 146
and 147.)

Secondly, so far from the allantois extending over the whole of
the inner surface of the sub-zonal membrane, or wall of the blasto-
dermic vesicle in Man, we are now given to understand that the
allantois of the higher Primates is a very insignificant structure
when compared with that of such a form as the rabbit.

For these reasons it is impossible to distinguish the discoidal
and metadiscoidal placentae in the way suggested by Foster and
Balfour, and it is suggestive to notice that the distinctions are not
insisted upon by later writers. Of these, Minot suggests a more
intelligible classification of placentae into, (1) true chorionic, and
(2) allantoic varieties ( Human Embryology, p. 376). In the former,
the chorion receives the blood vessels from the embryo by way of
the allantoic stalk, which may be a solid mass for the greater part
of its length (Haft-stiel); in the latter, the allantois grows rapidly,
its cavity enlarges, it becomes vesicular and covered with blood
vessels; its enlargement brings it into contact with the chorion,
and when the wall of the allantois touches the choi’ion, blood
vessels begin to pass from the former to the latter layer. The
higher Primates (and Tarsius) are found to be associated with the
unguiculate Eutheria in the first of these classes, while the lower
Primates (the Lemuroidea, except Tarsius) fall, with the Ungulata

D. M.

210

HUMAN EMBRYOLOGY

[SECT. B

and the other Eutheria, into the second group1. In this respect,
then, Man and the Anthropoidea are, as before, closely associated ;
it only remains to mention here that the recent researches of
Strahl (Selenka’s Studien, Heft XII. 1903), on the histology of the
fully- formed placenta of the Orang-utan reveals a practical identity
of structure with the corresponding human organ2.

We have thus considered the elementary conditions of the ovum,

1 It has already been remarked that a complete revision of the classification of
placentae is necessitated by the acceptance of the views of Hubrecht and Robinson
on placental structure. Robinson has proposed the following classification (op. cit.
p. 500, ibid.).

Placental varieties :

(A) Placentae appositae : no rupture, but simply separation occurs at birth.

(B) Placentao conjunctae : in which maternal and foetal tissues are closely
conjoined.

Both divisions are again sub-divisible, Group (A) including the varieties known
as (a) diffuse, (b) cotyledonary, and (c) some forms of zonary placentae. Group (B)
includes other forms of zonary placentae, and the discoidal form shared by Man,
the Apes, and certain other Eutheria.

2 Strahl’s researches on early Orang-utan embryos (Anat. Anz. 1902, p. 173).
The author has examined Selenka’s material, viz. five pregnant uteri of Simia
satyrus.

The youngest embryo would correspond to human embryos of about two weeks,
and is in general appearance very similar to these, but two striking differences were
noticed :

(a) The blastodermic vesicle is larger, the villi are stouter and more stunted
than in Man, and also less thickly aggregated : in each case the typical human cell-
layer and syncytial-layer were observed. Extension of an ectodermic covering to the
villi was not observed.

(b) The stnicture of the uterine wall is distinctive, particularly that of the
basalis-layer. Strahl says that the “basalisleisten ” (corresponding to the septa
placentae of Man, in whom the septa are much less regularly arranged than in the
Orang-utan, where they are radial), and the (radial) arrangement of the enlarged
uterine glands, constitute diagnostic peculiarities distinguishing the Orang-embryo
from that of Man at the corresponding stage. The older uteri confirm these obser-
vations, otherwise there is a close similarity to the human condition. Langhan’s
fibrin-layer could not be seen. More detailed accounts are given by Strahl in the
latest volume of the series commenced by Selenka, dealing with the embryology of
the higher Primates. A resume of this was given at the Heidelberg Meeting
of the German Anatomical Society in 1903. In the larger monograph, Strahl states
that the placenta of the Orang-utan approaches that of Man more nearly than that
of the Gibbon. Otherwise a general similarity in respect of the forms of the gravid
uterus and placenta in its later stages, obtains between the three types. The chief
differences are microscopic, and consist in the conformation of the uterine decidual
tissues. In Man, the syncytium is more extensive than in the Simiidae.

HUMAN EMBRYOLOGY

211

CHAP. VIII]

the mode of its attachment to the maternal tissues, and the
method of its nutrition. For the establishment of the close
connection between the circulations of embryo and parent is
followed by the exchange of nutritive material and products of
metabolism which fulfil the necessary conditions for progressive
development. And because the processes in other animals are so
fully and clearly described in the text-books, we have here dwelt
upon only such points as are of importance in the particular case
of Primate development. Up to this point we have seen that while,
in general, the human ovum goes through a series of phases which
find their counterpart in most mammals (some of them being
common to all vertebrates), yet the closest resemblances are with
the apes1.

We may further note that since the Primates present such very
distinct characteristics of development, it is not correct to describe
their embryology, as is so often the case, without clearly distin-
guishing it from that of other mammals. Again, we should notice
that of the peculiarities observed, it happens that in several
instances the characteristic feature is precocity of the formation
and appearance of certain structures, which are acquired more
slowly by other mammals. And the explanation offered for this
characteristic precocity seems a valid one, viz. that where so high
a specialisation in certain respects has to be attained, there will

1 One of the most recent reviews of the subject comes from the late Professor
Selenka (Centralblatt fiir Biologie, 1901), who points out the following close resem-
blances between the developing embryos of the Hominidae, of the Cercopithecidae,
and Simiidae:

(1) Precocious concrescence of the blastoderm with the newly formed uterine

mucous membrane.

(2) Precocity of development of the chorionic villi.

(3) Precocity of development of the mesodermic tissues.

(4) Precocity of development of the closed amnion.

(5) Precocity of development of the vitelline vessels.

(6) Tardy differentiation of the embryonic area.

(7) Reduction of the allantois to a short hollow cylinder.

(8) Pronounced retroversion of the vertebral column up to the 6th week.

(9) Modification of the allantoic stalk into a stout shaft of support.

(10) Attachment of the stalk of the yolk-sac to the shaft so formed (9).

On the other hand, cerebral differentiation makes its appearance as early as the
sixth to seventh week of development, and it is on considerations of the appearance
of the brain that reliance must be placed in distinguishing the human embyro at
this stage.

14—2

212

HUMAN EMBRYOLOGY

[SECT. B

of necessity be a tendency to abbreviation of the earlier phases,
•which are more protracted in such forms as have not to travel the
same distance beyond those early stages. The very early formation
of the amnion, the precocious appearance of the allantois, the early
formation and transitory functional period of the yolk-sac are thus
explained as abbreviations of the recapitulated history. But while
we find the closest approximation between Man and the Anthro-
poidea, in respect of early embryology, the chief evidence in those
portions of the history thus studied, of the close association between
Man and the Simiidae, is that discovered by Strahl in the charac-
ters of the histological structure of the placenta. (Cf. p. 210,
footnote.)

With regard to this part of the subject, the disc-like character
of the external form of the placenta has already been mentioned
(cf. Figs. 149 and 150, p. 208): in the Simiidae the disc is,
normally, single as in Man. Among the Cercopithecidae, as has
been already mentioned, two discs are normally formed (this occurs
as an abnormality in the Hominidae, v. supra, p. 201), and both
provide the foetus with nourishment. Pregnant uteri of Cerco-
pithecidae, with the fully formed placenta in situ, have been
described by Selenka1 ( Beitrdge zur Entwiclc.), Kollmann (Anat.
Anzeiger, 1900), and Keith ( Proc . Anat. Soc., May 1900, p. xlvi):
the latter observer remarks that the appearance of the two pla-
centae suggests their derivation from a zonary placenta, and the.
inference is submitted, that the ancestral forms of the Cerco-
pithecidae possessed the latter type of placenta. Keith further
recalls the fact that the Cebidae on the other hand are characterised
by a single disc-like placenta. We thus find the Hominidae,
Simiidae, and Cebidae allied, while differing from the Cerco-
pithecidae in respect of the external form of the placenta.

Other evidence we shall find, if we pass to the consideration of
a stage in embryonic development intermediate between those just
studied and the earlier of those (viz. 4 — 5 months) investigated
in the previous chapter. In the first place we may notice the very

] The description of twin placental discs in Hylobates is ascribed by Kollmann
to Owen. Selenka also described the placentation of Hylobates as bi-discoidal, but
wider research led him to the conclusion that this is anomalous, a single disc
occurring normally in the Hylobatidae (cf. Strahl in Selenka s Beitviige, Heft xu.,
p. 4‘21).

CHAP. VIIl] HUMAN embryology 213

peculiar dorsal flexure seen in the embryos of the Hominidae and

Figs. 151, 152, 153.

Fig. 151. (A) Human embryo; (B) Embryo of Hylobates rafflesii.

Fig. 152. (A) Human embryo; (B) Embryo of Semnopithecus cephalopterus.

Fig. 153. (A) Human embryo ; (B) Embryo of Macacus cynomolgus.

214

HUMAN EMBRYOLOGY [SECT. B

the higher Primates, at the 3rd week; it is considered by Minot to
be characteristic and distinctive of these.

Secondly, we may with the aid of Selenka’s illustrations in
the memoir just quoted ( Centralblatt fur Biologie, 1901), trace
the close similarity that obtains between the embryos of Cerco-
pithecidae and Hominidae in general appearance, and at the same

W.L.H.D. (after Selenka).
Fig. 154. (A) Human embryo; (B) Embryo of Semnopitbecus mitratus.

W.L.H.D. (after Selenka).

Fig. 155. (A) Human embryo; (B) Embryo of Macacus cynomolgus.

HUMAN EMBRYOLOGY

215

CHAP. VIII]

time note how marked a difference is produced by the elongation of
the tail in the former even at an early period. (Cf. Figs. 151 — 156).

The human embryo at successive stages from about the twelfth
day to about the forty-second day is indicated in these figures by
the letter (A), and compared with embryos of apes of corresponding
ages. The illustrations are slightly modified from those published
by Selenka.

W.L.H.D. (after Selenka).
Fig. 156. (A) Human embryo; (B) Embryo of Macacus cynomolgus.

Finally, when we compare the human embryo of about the
sixth week with the simian embryo figured by Selenka ( Beitrdge
zur Entw., Heft vn., p. 167, cf. Fig. 157), we note a very re-
markable similarity, most evident perhaps in the facial develop-
ment, and in the lack of prominence of the caudal vertebrae,
whose elongation even at this early stage characterises the embryos
of the lower Anthropoidea. It has not been demonstrated that
the tail of the human embryo at this stage contains any greater
number of caudal vertebrae than those which ultimately form the
coccyx1.

On the whole question then of the evidence to be drawn from
Embryology, we find that of Comparative Anatomy corroborated ;

1 Cf. Waldeyer, Sitz. der. kais. preuss. Akad. 1896.

216 HUMAN EMBRYOLOGY [SECT. B

we conclude that this evidence associates Man, firstly with the
Primates, and within that Order, in turn with the Anthropoid ea
and the Simiidae. With the embryology of the members of the
latter family (Simiidae), the development of the human embryo
runs parallel for so long a period, that the conclusion is confirmed,
which claims that tire Simiidae reproduce in many, if not all, respects,
a definite and comparatively recent phase in the history of Human
Evolution.

Fig. 157. A. Human embryo. B. Embryo of Hylobates mulleri
at an age corresponding to that of the human embryo represented in A.
C. Another aspect of the embryo Hylobates represented in B.

SECTION C.

VARIATION IN ANATOMICAL CONFORMATION.

CHAPTER IX.

ANATOMICAL VARIATIONS.

Following the evidence provided by Embryology, will be
taken that derived from the study of anatomical variations. The
investigation of variations has long attracted the attention of
biologists, and the recent advances, particularly in the statistical
treatment of data are extraordinarily great. While the lower
forms of animal life lend themselves more profitably to investi-
gation than the higher, yet even in the latter research has not
been barren. Of those who are foremost in this field, Bateson,
Pearson, and Weldon in this country, and Davenport in America
must be specially mentioned. In regard to the particular depart-
ment with which we are now concerned, the chief contributions
have been made by Testut1, Le Double2, Kohlbriigge3, Dwight4,
Macalister5, Cunningham6, and Huntington7, while at an earlier
date, Stieda8 published a treatise on the application of the theory

1 Testut, Les variations musculaires de Vhomme expliquees par Vanatomie
compurde.

2 Le Double, Traite des anomalies musculaires de Vhomme ; also Traite des
anomalies des os du crane.

3 Kohlbriigge, Atavismus, Utrecht, 1898.

4 Dwight, Anatomischer Anzeiger, Band xix.

5 Macalister, Boyle Lecture, Oxford, 1894.

6 Cunningham, J. A. and P. Yol. xxxm.

7 Huntington, American Journal of Anatomy, Yol. n., 1902-03, p. 157.

8 Stieda, Archiv fiir Anthropologic , Band xiv.

218

ANATOMICAL VARIATIONS

[SECT. C

of probability to the treatment of anthropological data, of which
the full value has only comparatively recently been realized.

Macalister’s Boyle Lecture is so important that a few notes
as to its purport must be added in the present place. The author
points out that the extensive study of anatomical variations leads
to the formulation of at least four generalised propositions, to the
following effect : —

(1) Organs which in the human body are least subject to
variations are, in the animal series also, the most constant and
uniform as regards their characters : and conversely, organs which
in the vertebrate series exhibit very diverse forms in different
groups of animals, present in the human body a high degree
of variability both in point of frequency and also of range or
extent. The mesencephalon may be cited in illustration of the
former, and the caecum, of the latter statement.

(2) Organs which have had a simple (ontogenetic) develop-
mental history are more stable than those whose formation is
the result of more complex processes.

(3) Of such parts as are repeated in series (such as teeth,
ribs, or vertebrae), the terminal members of the series are more
variable than the medial.

(4) Those parts are least variable which are the most uniform
and constant in their function ; and those are most variable which
present the greater range of function, or whose action is limited
by any conditions.

The foregoing generalisations are designated by the author,
(1) the ontological, (2) the embryological, (3) the homological, and
(4) the teleological propositions.

Secondly, Macalister insists on the desirability of a natural
classification of variations, and proposes the following categories,
viz. : anomalies of (1) quantity, (2) material, (3) repetition, (4) co-
hesion, (5) alternation, (6) position, (7) series, (8) inheritance,
(9) new formation : examples of the several classes are given and
their significance is fully discussed1.

1 It will be noticed that no special class is set apart for anomalies commonly
recognised as pathological deformities. As a matter of fact such pathological
variations, if their nature is investigated, will fall within one or other of the above
divisions.

CHAP. IX]

ANATOMICAL VARIATIONS

219

Finally, the questions of (a) the direction or trend of variation,
and (b) the continuity or discontinuity of variation are discussed.

Huntington (op. cit., cf. p. 217 supra) has proposed a classifica-
tion of muscular variations under the headings of (1) Fortuitous,
(2) Progressive, (3) Reversional variations, and has ingeniously
illustrated the third group with reference to the modifications
presented by the pectoral group of muscles in the Primates.

The application and significance of the study of variation in
the present connection is closely bound up with the study of
variations of the eighth class proposed by Macalister (Huntington’s
third group), i.e. variations of inheritance, or atavisms, the interest
of this branch of investigation depending on the consideration
that among the recorded departures from what may be regarded
as the normal (in other words the most frequent) conformation,
certain instances occur of the reproduction of characters constantly
found in other mammalian groups. Such occurrences, it has been
suggested, should be explained on the hypothesis that reversion
to an ancestral phase of evolution has here taken place ; and from
this it is argued that the abnormality is indicative of a stage
through which the ancestors of the individual passed in their
evolutionary progress. Like the pineal body, the thymus gland,
or the embryonic branchial clefts1, such variations are to be
interpreted as “ histogenetic memories ” (to quote again Professor
Macalister) of the features of ancestors of whose existence no trace
would otherwise remain. We have spoken above of “ certain
instances” and the qualifying adjective is used advisedly in view
of the fact that while, as explained in the preceding paragraph,
some anatomists have regarded all or almost all variations as
endowed with a reversive or atavistic significance, others are
disposed to deny to them any such value. As an exponent of
the “atavistic” school, the name of Testut may be mentioned2.
Diametrically opposed to the adherents to this view is Kohlbriigge.

1 A long list of anomalies considered by the author to fall within this class was
published by Raphael Blanchard, Revue il' Anthropologic, 1885, p. 425.

2 Although in the Boyle Lecture Macalister couples the name of Le Double with
that of Testut as referring all anomalies to atavism, it may be noted that Le Double
in his work on Muscular Anomalies, Vol. ii., p. 459, demurs to this; for, as he
explains, he adopts at least a threefold classification.

220

ANATOMICAL VARIATIONS

[SECT. C

Between these extremists will be found authors who, like Macalister,
prefer to steer a middle course, as safest in view of the limitations
of actual knowledge. For those who reject “atavism,” the difficulty
arises of explaining the undoubted occurrences of the abnormal
reproduction in one animal, of a structure normally found in
a second form (otherwise morphologically distinct), or of an ab-
normal type of conformation, which corresponds to the type which
is normally presented by a second form. The problem is further
complicated in many cases by the fact that the embryonic history
fails to provide any confirmatory evidence. It is, however, im-
portant to note that Huntington makes the following pregnant
statement: “...under adequate physiological stimulus an organ
may even be evolved de novo, along the same paths and following
the same developmental lines which far back in the phylogenetic
history of the species led to the production of its prototype, which
has in the course of the intervening evolutionary period become
rudimentary or adapted to other functional purposes.” If admitted,
the above possibility seems to render extraordinarily difficult the
establishment of the claim to base phylogenetic affinity on the
evidence of a given muscular anomaly.

Kohlbrugge regards all or almost all (for he makes the axillary
muscle almost the only exception) these occurrences as accidents,
explicable on mechanical ontogenetic grounds as yet but im-
perfectly surmised.

Were Kohibriigge’s views to receive universal assent, such
evidence of the descent of the Hominidae as might be forthcoming
on the hypothesis of the atavistic significance of variations would
fall to the ground ; and in anticipation of such a contingency, this
line of investigation might well be ignored in the present con-
nection.

But it cannot be said that such universal consent has as yet
been accorded to Kohlbriigge’s expression of opinion, and moreover
that author admittedly makes an exception to the general state-
ment. Until, therefore, a definite theory based upon considerations
of the action of mechanical forces in influencing embryonic develop-
ment shall have been evolved, it seems justifiable to review this
part of the subject, even though such a review be somewhat super-
ficial.

ANATOMICAL VARIATIONS

221

CHAP. IX]

Two slightly different lines of enquiry should here be dis-
tinguished. In the first place, the foregoing statements refer in
the main to variations at the extremes of oscillation from the
normal form, though linked to it by numerous intermediate and
less aberrant instances. Such extreme cases, when investigated
statistically, provide percentages too feeble numerically to render
instructive any comparisons instituted between forms in which the
normal types of conformation are not otherwise strongly contrasted.
The objections that may be raised to the interpretation of such
striking abnormalities will be diminished in the case of the less
startling divergencies, but the statistical study of the latter in
two groups of animals may also be productive of interesting results.
It follows therefore that in entering upon the study of variation
as elucidative of the relations of the Hominidae, we ought to dif-
ferentiate the cases of the very aberrant from the less divergent
types of anomalies.

In the second place, we must limit the range of comparison,
and clearly define the field into which our investigations shall
carry us. In accordance with the scheme laid down in Chapter I.
the comparison will here be limited for all practical purposes to
the Primates, and it would be manifestly irrelevant therefore to
deal seriously with such anomalous conditions as for instance hare-
lip, divided parietal bone, the musculus sternalis, congenital defect
of the radius, or of the corpus callosum, within such limits.
Numerous anomalies occur in Man which can only be paralleled
in comparatively lowly mammals, or even only in lower vertebrata,
such as reptiles or fishes1. But although, through limitations of
space, such wide considerations must be passed by with a simple
mention, it is important to reiterate that in the sum total of their
variations, the Hominidae are more closely allied to the Primates
than to any other Eutherian group. This demonstration has in
some degree been provided in the first six chapters of this book.

And yet again, within this range, we shall find it necessary to
further subdivide the work: for we have first of all to enquire
whether the variations from the normal structure constitute bonds
of affinity between the Hominidte and the higher Anthropoidea ;

1 An excellent introduction to this aspect of the case is provided in Wieders-
heim’s Structure of Man.

222

ANATOMICAL VARIATIONS

[SECT. C

and in the second place to institute a comparison of the variations
within the limits of the Hominidae, with a view to distinguishing
morphological types within that family: and should the latter-
expectation be realised, an attempt must finally be made to deter-
mine which, if any, of the types thus distinguished stands in the
nearest relation to the lower Primates.

We may therefore in the first place review some of the human
anomalies or variations which are found normally in one or other
of the Primates, after which the subject of the enquiry will
be the Hominidae themselves. Our examples of such reversive
anomalies are best exhibited in a tabular form, with references
to the lists of characters already provided in Chapter IV. (q.v.).
We there saw that in reference to the anatomy of normal examples
of the Lemuroidea the following conditions, which may ano-
malously obtain in the Hominidae, are of interest.

1. Extensive lacrymal bone.

2. Post-glenoid foramen.

3. Imperfect post-orbital wall. (Cf. Fig. 158.)

4. Entepicondylar (supracondyloid) foramen.

5. Twofold layer of cervical cutaneous muscles.

6. M. dorsi-epitrochlearis.

7. Extensive M. coraco-brachialis.

8. Bicornuate uterus.

While in comparison with the normal anatomical conformation
of the Anthropoidea, the following conditions are noteworthy :

9. Fronto-maxillary suture on the inner orbital wall. (Cf.
Fig. 159.)

10. Fronto-squamous articulation, instead of a parieto-sphenoid
articulation on the side of the skull. (Cf. Fig. 159.)

11. Additional rib-bearing vertebrae, especially in the lumbar
region.

12. The following muscles: M. omo-cervicalis, M. dorso-hume-
ralis, M. occipito-scapularis.

13. Absence of a vermiforrh appendix caeci.

14. Caudate lobe of liver.

15. Lobus azygos; impar.

CHAP. IX] ANATOMICAL VARIATIONS 223

Fig. 158. Imperfect post-orbital wall : the spheno-maxillary fissure being abnor-
mally wide : cranium of Australian aboriginal. (Mus. Anat. Cant. W.L.H.D. photo.)

Fig. 159. Fronto-squamou8 articulation in the temporal region, and fronto-
maxillary articulation on the inner orbital wall of the skull of an aboriginal native
of Australia. Cf. Figs. 21 and 33. (Mus. .Anat. Cant. W.L.H.D. photo.)

224 ANATOMICAL VARIATIONS [SECT. C

With special reference to the Simiidae the following characters
are to he noted :

16. Non-bificl cervical spinous processes.

17. A pre-sternal and meso-sternal articulation persisting at
the level of the third costal cartilage. (Cf. Fig. 162.)

18. Perforation of the olecranon fossa humeri.

19. Independence of the M. ischio-condylaris (adductor mass).

20. Variable origin of the M. soleus.

21. Disposition of the M. interossei pedis.

22. The formula for the great arterial vessels arising from
the aortic arch. The formula 3 + 1, viz., a common origin for the
right subclavian, right and left common carotid arteries with
independence of the left subclavian arteries is found in many of
the lower Primates. (Cf. Keith, J. A. and P., Vol. xxx. and
Parsons. J. A. and P., Vol. xxxvi.)

23. The arteria saphena longa.

Saccule

Fig. 160.

Fig. 160. Dilated laryngeal sacculus (from a specimen in the Anatomy School
at Athens).

Fig. 161. Simian type of the appendix caeci in a human infant.

CHAP. IX]

ANATOMICAL VARIATIONS

225

24. Dilated laryngeal saccules. (Cf. Fig. 160.)

25. The “simian” type of appendix caeci. (Cf. Fig. 161.)

Fig. 162. (A) Human sternum (of an Australian aboriginal) resembling the

stemun) of a Gorilla (B), inasmuch as the pre-meso-sternal articulation is opposite
the third, instead of the second costal cartilage. (Mus. Anat. Cant. W.L.H.D.
photo.)

With the foregoing list of illustrations, our consideration of
the first part of the subject of anatomical variations must ter-
minate, giving place to the more detailed comparison ( inter se )
of the various morphological types of the Hominidae. Incidentally,
however, it may be necessary to recur to the consideration of some
of the anomalies of conformation which have found a place in the
above selection. This detailed comparison will form the subject
of the next six chapters.

d. m. 15

CHAPTER X.

COMPARATIVE CRANIOLOGY AND CRANIOMETRY.

An appeal was made (in Chapter vm.) to the embryological
history of Man, in the search for evidence indicative of the precise
path traversed by his ancestors in their evolutionary progress
towards the actual human stage. And from embryology the
evidence forthcoming, while it indicates that what may be termed
an ape-stage marks an epoch in that progress, has not yet provided
more exact details than such, for example, as suggest that the
history runs for a longer period with that of the Simiidae than of
the Cercopithecidae. But no single example among the larger
Simiidae can be pointed out with confidence, as embodying the
characters of the human ancestor at the simian stage of evolution
more completely than any other, though there is a slight margin
of evidence in favour of the Chimpanzee, rather than the Gorilla
or the Orang-utan. We must therefore acquiesce for the time in
what is admittedly a somewhat disappointing result, and await
the acquisition of more delicate means of analysis and observation
applicable to embryological study. Of the other remaining lines
of investigation, that which treats of anatomical variations and
departures from the modal type was shewn to be appropriately
divisible into two sections. The first of these indicated very briefly
the general evidence for the occurrence in human morphology of
variations to which an atavistic significance may reasonably be
attached. There remains for consideration the second section,
viz. that which relates to the comparison of the human
races, with the object of ascertaining whether simian characters

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 227

are present in any particular race more numerously or in a higher
degree than another. Thus we are concerned with studies, which
may be collectively designated of the comparative morphology
of the human races.

These studies consist in the examination of the varieties of
mankind, and of their relations one with another. For present
purposes indeed, the field in which evolution is supposed to have
occurred must be here regarded as circumscribed within narrow
bounds.

Hitherto we have considered mankind as uniform in morpho-
logical characters, and this uniform type has been compared with
several other Eutherian types. Henceforth we are to take account
of the differences existing within the limits of the family
Hominidae, and to enquire whether any evidence (and if any of
what nature) is forthcoming as to morphological evolution within
those limits : to compare or contrast the white man with the negro,
with the yellow man or pigmy, and to deal with these as
zoological forms subject to the same variations of environment as
so many larger groups of mammals. With this object in view the
material and the methods of study claim attention : inasmuch as
the former is at present limited almost entirely to the skeleton,
we must commence with the study of this system, proceeding
afterwards to the consideration of either material representative of,
or data drawn from descriptions of other systems. As before, so in
the present connection, the skull will be first considered, and we
have now to take up the subject of Comparative Craniology and
the methods employed in its elucidation.

(1) With a view to coordinating observations upon skulls, certain
preliminary considerations must be submitted, and the first of these
consists in the recognition of the fact that a skull, being roughly
comparable to a cubical object, of necessity presents six surfaces
for examination. The view obtained of any of these surfaces is
defined as the norma of that surface, and consequently normae are
recognised as follows ; norma verticalis, the view of the vertex,
from a point above the skull, this term was devised by Blumenbach;
and to it were subsequently added, norma lateralis (the side view),
norma facialis (the full-face view), norma basilaris (the basal view),
and norma occipitalis (the back view of the skull). (Cf. Fig. 163.)

15—2

228

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

Fig. 1(53. The human skull viewed in (1) norma verticalis, (2) norma lateralis,
(3) norma facialis, (4) norma basilaris, and (5) norma occipitalis. In (2) the skull
is so placed that the “ base line of the Frankfort agreement ” (viz. the line passing
through the lower margin of the orbit and the upper margin of the auditory
meatus) is horizontal. The dotted lines in (2) represent the maximum cranial
length, as well as the cranial length in a direction parallel to the “ base-line,” i.e. the
cranial length in “ projection,” measured from the glabella anteriorly. The crosses
in (3) mark the points between which the cranial, facial, orbital, and nasal widths,
and also the orbital and nasal heights are measured. The dotted lines in (4) indi-
cate the diameters of the hard palate, as measured conventionally in Flower’s
system.

(2) Secondly, the definition of certain points on the surface of
the skull facilitates “regional” descriptions. The most important
of these points are included in the following list, in which their
positions are verbally defined. The numerical references are to
Fig. 164.

Bregma. The point at which the sagittal and coronal sutures meet (1).
Obelion. A point in the sagittal suture midway between the parietal
foramina (2).

Lambda. The point at which the sagittal and lambdoid sutures meet (3).
Inion. The most prominent point on the external occipital protuberance (4).
Opisthion. The mid-point on the posterior margin of the foramen magnum (5).
Basion. The mid-point on the anterior margin of the foramen magnum (6).
Prosthion. The most prominent point on the alveolar margin between the
two upper median incisor teeth (7).

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY LL'd

Akanthion. The most prominent point on the nasal spine (8).

Ehinion. The most prominent point at which the nasal bones touch each
other (9).

Fig. 164. Diagram of a skull with indications of the principal named points ;

the lines refer to certain measurements “in projection” to which further reference

will he made in the text.

Nasion. The point at which the internasal suture meets the naso-frontal
suture (10).

Glabella. The most projecting point of the frontal bone, at the level of the
supra-orbital ridges (11).

Ophryon. A point in the median plane, and at the level at which the
temporal ridges (which converge immediately above the external
angular processes) are most closely approximated (12).

Pterion. A point at the posterior end of the parieto-sphenoid suture (13).

Stephanion. The point of intersection of the coronal suture and temporal
ridge1 (14).

Asterion. The point of confluence of the lambdoid, squamo-parietal and
squamo-occipital sutures (15).

Pogonion. The most prominent point of the chin as represented by the
mandible (16).

Dacryon. The point of confluence of the fronto-lacrymal, fronto-maxillary,
and lacrymo-maxillary sutures on the inner orbital wall (17).

1 Where an epipteric bone is present the exact situation of this point is

indeterminate.

230

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

A note on the derivation of the foregoing names may not be
without interest.

Bregma, fipeyp.a, /3p<?xco, to wet ; hence to soften. Hippocrates considers it
is so called because this part of the skull remains soft longest.

Obelion. o/JfXdy, a spit. Application obscure.

Lambda. Fi-om the resemblance to the Greek letter.

Inion. Ivlnv, the “tendon-point” from the attachment of the nuchal
ligament.

Opisthion. oma-d t, the “ hind”-point.

Basion. ftdair, the “ base ’’-point.

Prosthion. npdarOt, the “ fore ’’-point.

Akanthion. aKavOa, the “ spinous ” point.

Rhinion. pis, the “ nostril ’’-point.

Nasion. JVasus, the “ nasal ” point. (A barbarism.)

Glabella. Qlabcr, smooth, from the smooth area round this point where the
hairs of the eyebrows are deficient.

Ophryon. dcfrpvs, eyebrow. The “ eyebrow ’’-point.

Pterion, nrepov, the “ wing ’’-point.

Stephanion. arri^avas, the “ crown ’’-point.

Asterion. aa-rrip, the “star ’’-point.

Pogonion. ira>ywviov, the “ beard ’’-point.

Dacryon. baiKpvov (or Sanpv), the lacrymal point.

(3) Orientation. In the third place, it is a matter of con-
venience to determine some definite position in which crania shall
be placed for examination and comparison, for it is found that the
eye may be greatly deceived as to such features as prognathism,
frontal prominence or the reverse, by the amount of tilting forward
or backward to which the specimen has been subjected. Several
“ planes of orientation ” have been suggested, and in most cases
a horizontal plane, determined by the natural conformation of the
skull, has been sought: thus the plane of the “ visual axis,” and the
alveolo-condylar planes (of which the names are sufficiently descrip-
tive), have been used by some observers, the latter being
particularly associated with the name of Broca. Less natural
perhaps, but on the other hand more accurately horizontal and
quite as easily defined, is the plane adopted by German observers,
which is determined by the line passing from the inferior margin
of the orbit in front, to the superior margin of the external
auditory meatus posteriorly (cf. Fig. 165). It will however be

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 231

noticed that this line should be drawn on each side of the skull,
and that owing to asymmetry of form, the four points (viz. two

Fig. 165. Human skull placed in position, with the “ base-line ” of the
Frankfort agreement in the horizontal plane.

infra-orbital and two supra-meatal) may not be strictly in one and
the same plane. . Allowance for this drawback has to be made, and
the asymmetry which determines it must naturally occur in every
object not constructed with absolute regard to strict geometrical
principles. But the same objection applies to the other planes of
orientation mentioned above.

The last mentioned plane is named from the determining line
which is called the horizontal line of the Frankfort agreement
(from the locality at which a conference of German observers drew
up a system of craniometrical instructions) : and it will be seen
that when the skull is placed so that the plane determined by this
line is horizontal, the natural resting position of the head of the
living individual though inclined forwards rather than backwards, is
nevertheless closely imitated. The recognition and determination
of such a base-line is of much use in the comparison of cranial forms.

Being thus acquainted with the significance of the term norma
and with the various normae, and recognising the named points

232 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

on the skull and the points by which the horizontal or base-line is
determined, we may proceed to consider briefly the method of
drawing up a craniological description.

The method here proposed involves the consideration of the
skull as morphologically composed of, (a) the cranial part proper,
consisting of such bones as are developed in connection with the
coverings of the encephalon, ( b ) the derivatives of the visceral-arch
skeleton, and first and second sense-capsules, which are collectively
described as the facial portion ; and (c) the cephalic portion of the
axis of the skeleton, locally termed the basis cranii. Each of these
divisions should be examined in turn, the appearances seen in the
several normae being noted and particular features localised by
reference to one or more of the mimed points (of which a list has
been given). The accompanying scheme does not pretend to be
exhaustive, but it has been found of practical use in the further
systematisation of observations. It is moreover similar to the
scheme adopted in the description of simian skulls in Chapter v.
(q. v.).

I. Cranial Portion.

General Contour : In norma verticals this may present an elongated
narrow appearance, or on the other hand be short or almost
circular. In norma lateralis the transverse curve of the
vault may be uniformly rounded, or it may be scaphoid, i.e.
keel-shaped.

Sutures : these may be absent : or be very tortuous, or almost
rectilinear. They may be abnormal in number.

Ridges : these vary considerably as regards their prominence.

II. Facial Portion.

Orbit : General contour and margins : the cross diameters of the
orbital aperture may be nearly equal, or the vertical may be
much less than the horizontal.

Lacrymo-ethmoidal suture : this may be short, or long, or absent,
when a fronto-maxillary suture usually replaces it.

Lacrymal hamulus : very variable in size, more usually small than
large.

Infra-orbital suture : variable in persistence.

Nasal aperture :

General contour ; ovoid, pyriform or cordate.

Lower margins : distinct or obliterated, with or without subnasal
fossae.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 233

Nasal spine : variable in prominence.

Nasal bones : variable in size and shape.

Palate. General contour: this may be elliptical, hypsiloid ox-
parabolic according as the two alveolar arcades are con-
vergent, parallel or divergent.

Post-palatine spine : variable ixx prominence and sharpness, often
notched.

Tuber maxillare : variable in size.

Palatine sutures: frequently depart from the cruciform arrange-
ment descx-ibed in text-books.

III. The Temporal Fossa.

Sutures at pterion : these may assume an H-form, inverted H1, or X.

Depth of fossa : variable and dependent on several factors.

Post-oi-bital wall : variable in degree of completeness.

IY. Base of the Skull.

Glenoid fossa : sometimes very shallow.

Max-gin of foramen magnum : such variations as accessory articular
facets for the atlas (posterior arch) or the odontoid process of
axis are to be remarked.

Styloid process : variable in length.

Y. Dentition.

Number of teeth.

Characters of teeth.

VI. The Mandible. »

The foregoing characters having been noted, the evidence pro-
vided in this manner is to be brought to bear, first upon the
approximate age of the individual, i.e. whether still infantile, or
at the age of puberty, or mature ; secondly, upon the question
of sex; and thirdly upon the general status of the specimen as
judged by its morphology. A fuller discussion of these three
subjects will provide material for subsequent chapters (Nos. xi.
and xvi.).

These remarks will furnish some idea of a scheme which has
proved of practical use both in research and instruction, and the
several anatomical points contained in the various sections are
accompanied by the briefest of statements as to what should be
specially recorded. Very many other characters might be added
to the list, but it is believed that those just enumerated are the
most valuable for the purposes described.

The outcome of these observations as regards the human skull

1 The letter H placed on its side was thus described by Broca.

234

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

in comparison with those of the Simiidae for instance, may be
gathered from references to the description of the skulls of
Simiidae given in Chapters iv. v. and VI., while the results of such
investigations when directed to the skulls of various types of
humanity will be considered in a later chapter.

While an historical account of the development of the com-
parative study of skulls is without the scope of the present work,
it may be noted that the subject is dealt with certainly as early
as the sixteenth century by Vesalius, though the fanciful may
claim Herodotus or even Homer1 as the earliest craniologist. In
our own time, descriptive craniology has been largely supplemented
by craniometry, an account of the methods of which naturally
follows in this place. Nevertheless certain observers, who have
achieved no little notoriety in this field, have almost absolutely
rejected numerical or craniometrical methods. Chief among these
is the Italian Sergi, who has elaborated a system devised originally
by von Baer at Gottingen at the beginning of the nineteenth cen-
tury. But Sergi has carried the purely descriptive method to such
an extreme as renders its use almost impracticable, owing to the
minuteness of detail which suffices for the creation of new specific
cranial types, and their consequent multiplication. In spite how-
ever, of this objection to craniometry, we must note that Sergi
retains measurements of capacity. We shall see in the sequel
that the craniometrical method has been similarly extended to an
exaggerated degree, with a somewhat similar result as regards its
practical utility.

In this study (Craniometry), which consists essentially in
supplementing descriptive by numerical data, we find at once that
several distinct groups of methods claim attention. For dis-
tinctions must be drawn between the several kinds of measurement
employed, and thus we are led to the recognition of measurements
which may be described in order as

(1) rectilinear,

(2) curvilinear,

(3) angular,

(4) cubical, or measurements of capacity,

(5) ponderal, or measurements of weight,

1 Herodotus, Book in. chap, xii; Homer, Iliad, ii. 219.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 235

and a few words of explanation may now be added in relation to
each of these classes1.

(1), (2). Rectilinear and curvilinear measurements : these
are so closely allied that they may be considered together. It
seems very natural that the inspection of a skull, with a view to
measuring it, should result in the posing of the questions “ How
long, broad, and high is it?” or “how much does it measure
round ? ” the answers to these questions are arrived at by the aid
of measurements of length, breadth, height and circumference, and
these are in fact the most firmly established measurements in
systems of craniometry. One finds moreover that any one of these
four dimensions will vary, according to the plane in which the
measurement lies, so that numerous measurements of the length
as well as of the breadth, height and circumference of the skull
have been devised. But whatever be the particular measurement
adopted, one should be guided in its selection by considerations
of its value as expressive of the proportions of the brain by which
the skull is protected.

It will be noticed that although not based upon strict con-
siderations of morphology, measurements were soon made upon

1 A brief note on the historical aspect of Craniometry (as distinct from simple
Craniology) is appropriate here. The earliest record is probably that of Bernard de
Palissy (1563), who suggested, though he did not apparently practise, cranial
measurements. In 1600, Spigel made similar suggestions with a view to expressing
differences in skull-forms by this method. In both these instances only human
crania were taken into account. Tyson (1699) made some measurements of the
skull of the Chimpanzee dissected by him (cf. Chapter i. foot-note); and in 1764,
Daubenton published observations of great importance dealing with the relative
position of the foramen magnum in the lower animals and in man (cf. Chapter v.
pp. 114 to 119) ; lack of precise methods in making measurements somewhat
vitiated the value of Daubenton’s work. He was followed by Peter Camper
(1722-1789), to whose work, including the “method of projection,” and the
description and measurement of facial angles (he devised at least two), allusion
has already been made ; and in subsequent succession come the names of Cuvier
and Geoffrey S. Hilaire, to whom credit is due for having made comparative
craniological investigations on the Primates, utilising an angular measurement
since associated with their names. While Blumenhach paid less attention to
measurement than description, the Swedish anatomist Retzius made important
craniometrical observations in the earlier years of the XIXth century, and we are
thus carried to the days of Broca, Lucae, and modern observers too numerous
to mention.

236

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

the cranial as distinct from the facial part of the skull: but it was
not till distinct advances had been made in the morphological
study of the skull, that guidance in the selection of appropriate
measurements was obtained. Measurements whether of the
spheroidal cranium, or of the face and mandible, were rapidly
augmented in number, and when it is added that the actual
operation of making measurements demands no high degree of
manipulative skill, nor, when undertaken empirically, as has so
often happened, does it involve very extensive preliminary ex-
perience or prolonged preparatory study, it is easily intelligible
that such augmentation might occur as has actually been the
case, and that, as is also the case, thousands of measurements
have been published though accompanied by very little elucidative
literature. Empiricism was once the order of the day ; as a guiding
principle it proved unproductive; indeed it has brought craniology
into disrepute. To the definite enunciation and application of
morphological principles to craniological studies and craniometrical
methods we owe much to British observers, among whom Huxley,
Flower, and Turner must be specially mentioned, while progress
in this respect has been indirectly due to all whose work has
contributed, like that of Gegenbaur, Lucae, Cleland, and Topinard,
to the fuller knowledge and appreciation of cranial morphology.

With these introductory remarks we may pass to the appended
list of rectilinear and curvilinear measurements, a list of no great
length, but yet containing the measurements believed to be of
most importance from the stand-points of research, of demonstra-
tion, and instruction.

Dimension.
Cranial Portion.
Maximum length.

Maximum breadth.

Method of Measurement.

From the glabella to the most prominent
point of the occiput in the median
sagittal plane. Crania of women and
children may occur in which the maxi-
mum length will pass from the upper
part of the frontal bone (above the
ophryon and glabella) to the occiput.

Measured on the cranial part (not the face)
above the auditory meatus, and usually
on the parieto-squamous suture.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 237

Dimension.

Basal height.

Auricular height.
Horizontal circumference.

Facial Portion.

Auriculo-nasal length.
Auriculo-prosthionic length.
Basi-nasal length.
Basi-prosthionic length.
Nasi-prosthionic length.
Bi-zygomatic breadth.
Bi-stephanic breadth.
Orbital height.

Orbital width.

Nasal height.
Nasal width.

Method of Measurement.

From basion to bregma.

From the inter-auricular line to the bregma.

The flexible measure passes along the brow-
ridges and glabellar prominence in front,
and over the projecting portion of the
occipital bone behind.

From the inter-auricular line to the nasion.

From the inter-auricular line to the prostliion.

From basion to nasion.

From basion to prosthion.

From nasion to prosthion.

Greatest diameter of zygomatic arches.

From stephanion to stephanion.

The maximum vertical height of the orbital
aperture.

From the dacryon to the outer margin of the
orbital aperture, at right angles to the
preceding line.

From nasion to akanthion.

The maximum width of the nasal aperture.

As in descriptive craniology, the divisions of cranial and facial
portions of the skull have been recognised. With the names of
the measurements in the foregoing list instructions and definitions
are given, to which may be added a few remarks in the present
place. It will be noticed that in several instances the measure-
ments are made between points to which are applied the particular
names detailed at an earlier period in this chapter; in perusing
the instructions for making the measurements, reference is thus
necessary to Fig. 164 respecting the positions, and to the list of
definitions of those points, which therefore need not be recapitu-
lated in the present connection.

Maximum length, maximum breadth. These measurements,
and indeed all the others in the list with the exception of the
horizontal circumference, are most conveniently made with the
aid of a pair of callipers such as Flower’s Craniometer (Fig. 166),
or the model more commonly used in Germany (Fig. 167).

Besides the maxima, various other measurements have been
suggested both of length and breadth, such as the ophryo-occipital,

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

or the ophryo-iniac, the nature of which is indicated by their names
(they are determined by the ophryon anteriorly, and not by the
glabella) ; but on the whole it has not been shewn that they are

Fig. 166. Fig. 167.

Fig. 160. Flower’s Craniometer in the position for measuring the maximum
cranial length.

Fig. 107. A second variety of Craniometer.

of greater value than the maximum length, though no doubt they
supplement the information conveyed by the latter measurement.
To the description of the mode of measuring the maximum
breadth, it should be added that this breadth is practically always
in excess of the diameter at the base of the mastoid processes,
which may be considered as the diameter of the skull-base,
a chord which is less modified by the growth of the encephalon
than that measured higher up between points in the membrane-
bones of the skull-cap.

Basal height. This measurement might be made from the
basion in a plane at right angles to the horizontal plane as defined
by one or other of the methods mentioned in the note on “ orien-
tation ” ; but as a matter of practical utility the results afforded
by the basi-bregmatic height are not appreciably inferior to those
yielded by the strictly vertical height.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 239

Auricular height. To make this measurement, Cunningham’s
craniometer or Pearson’s head-spanner must be used. As indi-
cated in the note appended to this measurement in the list (q.v.),
the object in view is to determine the distance separating the
bregma from the inter-auricular line, i.e. the line drawn from the
centre of one auditory meatus to the other. The instrument (cf.
Fig. 168) consists of the following parts. Two bars (A and A') are

}

Fig. 168. Pearson’s head-spanner in the position for measuring the auricular
cranial height.

joined by a crosspiece about 200 mm. long, so that the bars and
crosspiece form a frame representing three sides of a square. At
their free or lower ends, A and A' cany geometric slides in which
slender rods (B, B') play towards, or away from each other, and at
right angles to A and A', but always in the plane of the frame.
B and B' are terminated at their inner ends by conical tips
adapted to the form of the auditory meatus. The crosspiece also
bears, at its middle point, a geometric slide in which a graduated
rod B , similar to B and B', plays at right angles to the crosspiece,
but like B and B', in the plane of the frame.

In using the instrument, B and B' are first separated to admit
of a skull being placed between them and then they are approxi-

240 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

mated till their conical ends enter the meatus each side. Rotating
on B and B' as an axis, the whole frame can now be moved for-
wards and backwards over the skull. Two adjustments are now
necessary : in the first place B and B' are moved so that the mid-
point of the crosspiece and B" are in the median sagittal plane of
the skull : and secondly, B" is moved towards the skull till any
desired point in that plane is touched. Here the bregma is the
point in question, and B" is so graduated as to give directly the
distance of the bregma from the line joining B and B', i.e. the
inter-auricular line.

Horizontal circumference. This measurement is made with
a flexible measure of steel or linen ; the latter material is less
exact, for it is liable to stretch, yet its employment is justified by
the fact of its fitting more closely the form of the skull than the
more rigid metallic ribbon does. The maximum circumference
including the glabellar, supra-orbital, and occipital prominences
is measured. The measurement of the horizontal circumference
as made by Flower does not include
the glabella. The retention of this
particular method is not justifiable in
view of what has just been written
regarding the measurement of maximum
length, and it is only retained because
of the existing comparative data, a
consideration of much less force in the
case of the maximum length. Turner
measures the maximum circumference
(Fig. 169) as described above ( v . p. 237).

The auriculo-nasal and auriculo-
prosthionic lines are measured with
Pearson’s or some similar craniometer, and represent the radii
from the ear to the nasion and prosthion respectively. Their
value depends largely on the consideration that the corresponding
measurements are easily made on living subjects (cf. infra,
Chapter xm. “Anthropometry”).

The basi-nasal length is important as representing the length
of the cranio-facial axis. The only objection that might be urged

Fig. 169. Diagram in which
the broad band represents the
line of the horizontal circum-
ference according to Flower;
the narrow band represents the
line adopted by Turner and
described in the text.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY * 241

against it, is that the nasal bones are liable to variations in vertical
extent, and that the position of the nasion (which determines
the line) is in consequence subject to variations which are only
remotely connected with those of the bones of the cranio-facial
axis. In man these variations are probably only slight, but in the
Simiidae they are more important, and hence introduce an element
of uncertainty into comparisons of the Hominidae and Simiidae
based on the actual dimensions (though less on those based on
the position and relations) of this line.

The basi-prosthionic and nasi-prosthionic lines complete a tri-
angle which may be termed the facial triangle.

The next two measurements are diameters of the cranial and
facial portions of the skull respectively, and are chiefly of interest
when compared with one another, as described in the sequel (cf.
Chapter XI.), as the stephano-zygomatic index.

The orbital and nasal measurements were devised to represent
the proportions of the height and width of the orbital and nasal
apertures respectively: it may be mentioned that the orbital-
width-measurement includes the whole of the lacrymal bone within
the orbit. Upon morphological grounds this is incorrect, and it
has been urged that the line of the crest or ridge on the lacrymal
bone should be taken, so that the measurements should include
but one half only of the bone within the orbit. The position of
the dacyron is however so definite, and the difference between the
two alternative diameters so slight, that the simpler line, as more
easily measured, has been retained in the foregoing list.

It will doubtless be remarked that in the preceding notes no
mention is to be found of the principle of making measurements
in projection, nor has the method of projections been recommended
in this connection. The method may be briefly explained in
reference to the example of the measurements recommended by
the Frankfort Congress. In the first place the skull to be
measured is so orientated that the base line is horizontal (cf.
fig- 170). Suppose that the length and height (basal) of the
skull are to be measured. Ordinarily, the maximum cranial
length from the glabella1 would be measured : “ in projection,”
however, the dimension measured is the length from the glabella
1 Between the points marked 11 and 4 in Fig. 170.

D. M.

242

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

to the occipital end of the skull, in a plane parallel to that of the
base line \ In regard to basal height, the height measured from
the basion is, according to our system, the basi-bregmatic height2,

Fig. 170. A human skull in which the principal points are indicated by numerals.
The line from 11 to 4 is the maximum length of the cranium : that from 11 to x is
the length “in projection.” The line from 1 to 6 is the basi-bregmatic height: the
line immediately behind this is the height “in projection.”

and in the diagram is represented by the line drawn between
basion and bregma. In projection, the basal height is the height
of the line drawn from the basion perpendicularly to the base line,
and is accordingly shewn by a line in the diagram cutting the top
of the skull at a point which does not coincide with the bregma.
The method of projections demands that all measurements shall
be in planes parallel or perpendicular to the horizontal plane of
orientation determined by the base line. Such a refinement is
undeniably a step in advance as regards accuracy of comparison
and uniformity of treatment. But against these advantages we
have to set off the increase in labour entailed for the measure-
ments, and when it is added that the results of the more compli-
cated system have not as yet been shewn to be markedly superior

1 Between the points marked 11 and x in Fig. 170.

2 Between the points marked 1 and 6 in Fig. 170.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY

to those simpler methods described in the text, it is submitted
that there is justification for adherence to the latter.

(3) Angular measurements. From linear measurements we
pass to the measurements of angles. From a considerable number
of angles of which descriptions have been given we shall select five,
the choice being determined by the value of the angle as illus-
trative of morphological conformation and its variations from skull
to skull.

The best known of these angles is the facial angle, which is
used as a means of illustrating the difference between the pro-
jecting “prognathous” facial skeleton of various animals and the
corresponding portion of the skull of the Hominidae. The term
“facial angle” is no longer new: tradition ascribes to Albrecht
Diirer the description and employment of a facial angle1 in artistic
studies : but there is no doubt that the capabilities of this method
of comparison were originally recognised by the Dutch artist and
anatomist Peter Camper (to whom reference has already been
made) in the eighteenth century. As described by Camper, the
facial angle was determined upon the intact skull, unmodified, that
is, by any section having been made. But it is to be noted, that
the median sagittal section of the skull provides a plane surface
revealing several morphological characters susceptible of illustra-
tion by means of angular measurements, also conveniently made
on such a surface. We must therefore distinguish angles measured
on the external surface of the skull from those determinable upon
sections of the kind just described. Camper’s facial angle is an
example of the former variety, and though the including lines as
defined by Camper have been amended, and various other facial
angles of a similar nature have been proposed, we shall describe it
with one other in the list of angular measurements to be made on
non-sectionized skulls.

The facial angle of Camper is included by two lines (cf. Fig. 2),
viz., a facial line, and a base line or “ horizontal ” line. The facial
line is tangential to the most prominent part of the frontal bone
in the neighbourhood of the glabella, passes downwards, and is
tangential to the slight convexity forwards of the upper incisor
teeth : the lack of definition of the latter (lower) point is due to

1 And it is certain that this artist made use of a facial line, on the subject
of which he wrote a treatise.

16—2

244

COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

the fact that the angle was described by Camper as determinable
upon the head when clothed with the soft tissues as in life, just as
conveniently as upon the macerated skull. The facial line in the
head passed through the point of contact of the lips (as seen in
profile): this is best represented by the most anterior point on
the surface of the upper incisor teeth, and this consideration has
determined its selection in the skull1.

The horizontal or base line adopted by Camper passed through
the lower part of the nasal aperture, backwards along the line of
the zygomatic arch, and through the centre of the external
auditory meatus, and in the case of the measurement being made
upon a head, the line approximately corresponds to that of the
nostril as seen in profile2.

The two including lines are found to intersect in the neighbour-
hood of the nasal spine, and the angle thus formed was shewn by
Camper to vary from a comparatively small number of degrees
representing its value in the skull of a lowly mammal or reptile,
ascending through the higher Mammalia, and the apes, and thus
gradually through the negro to the white human type, culminat-
ing in the idealised heads which Greek artists of antiquity gave
to their masterpieces of sculpture.

With the remark that a weighty objection to this angle was
the lack of definition of the points by which its including lines
were determined (and in particular the presence of the incisor
teeth is essential in this respect), we pass at once to the considera-
tion of another facial angle, the including lines of which are more
definitely fixed. The facial angle recommended by the members
of the Frankfort Congress is included like that of Camper, by
a facial line, and a base-line.

The facial line passes through the nasion above and the
prosthion below : the horizontal or base line is that already defined

1 Camper’s description is not quite clear: it runs as follows (cf. Camper's
Works-, ed. by Cogan, 1821): “As the closing of the teeth marks the mouth at
‘G,’ I was able to draw an oblique line from ‘G’ to ‘M’ along the nasal bone of
the forehead.” But inspection of the diagrams leaves no doubt that the meaning is
that given in the description above.

2 Topinard remarks that the base line of Albrecht Diirer, passing through the
lower part of the nose and through the lowest part of the lobe of the ear, is more
exactly horizontal than Camper’s line.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 245

as the base line of the Frankfort agreement, and passes through
the infra-orbital margin and the upper margin of the external
auditory meatus. Like that of Camper, this angle may be deter-
mined upon the head as well as on the skull, and the results of
a comparison of its value in various animals are similar to those
derived from the study of Camper’s angle.

Before passing from the description of the angles measured on
the skidl exteriorly to the consideration of angles determinable
only upon median longitudinal sections, it must be noted that the
angles of Camper and of the Frankfort agreement (the latter may
be termed the Frankfort angle) are in practice best determined
by measurement upon projected drawings whether of head or skull.
Ranke’s goniometer is an instrument specially devised for the
purpose of measuring such angles, but (without raising objections
on the score of the costliness of the instrument) it is submitted
that equally good results are obtained upon projected outlines, and
the latter method was actually practised by Camper. The stereo-
graph affords an excellent means of making the desired drawings
(this applies to section-
ized as well as to in-
tact skulls), and it is
not necessary to draw
a detailed contour, no-
thing more being need-
ed than an indication
of the four points de-
fining the two lines by
which each angle is
included. The simplest
method of making such
a projection-drawing is
to place the object on
a sheet of paper and
to run a pencil, per-
pendicularly to the
paper, round the cir-
cumference of the ob-
ject. But where the
object is not adapted

Fig. 171.

246 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

to the plane surface of the paper it must be held in position.
The stereograph (cf. Fig. 171) consists1 then (a) of a craniophore
or skull-holder ; secondly ( b ) of a drawing-board on which the
paper for receiving the drawing is pinned, and lastly (c) of a
frame in which the pencil is held accurately and perpendicularly
to the plane of the paper. When we add that the frame is so
modified as to admit of other features than the circumferential
contour being drawn in, an idea will be gained of the nature and
capabilities of the instrument of which a figure is appended2.

It will be apparent that when angles are to be measured no
contour is necessary, all that is required being the position of the
several points by which the lines are determined ; these can be
indicated very rapidly and accurately, and the desired lines drawn
upon the paper.

We now pass to the angles measured on the sectionized skull.
A retrospect of the remarks (cf. Chapter vi.) on the appearance of
the component parts of the skull as revealed in a median longitu-
dinal section, shews that the principal elements displayed may be
classified under the three categories, or three portions of the base,
known as the anterior base, middle base, and posterior base respec-
tively. It will further be remembered that from the comparison
of various skulls the inference is drawn, that in evolution, changes
have occurred in the inclination of the several segments of the
cranio-facial axis represented by the anterior and middle bases
respectively. The angles now to be described are measured with
the object of obtaining numerical expressions for the degree of
inclination in such examples ; as well as for the demonstration,
with the aid of numerical data, of the mode and degree of trans-
formation observed from skull to skull, whether the subjects of
comparison be human and other animal skulls, or the comparison
be confined within the limits of the Hominidae. For such
purposes several angles have been devised, but the three which
follow are considered ample for all practical purposes.

1 v. also supra, Chapter i. (p. 9).

2 Another method was devised by Camper; the object is placed behind a frame
across which strings are stretched: the drawing is made on paper, with lines
corresponding to the strings, marked upon it. This method has been elaborated in
the instruments of Lucae in Germany, Matthew in the United States, and Martin
in Switzerland.

'ki.nS.

Fig. 172. Mesial section of the skull of
an aboriginal of Australia, shewing the
three divisions of the cranial base, viz.
Pr — N, B — Pr, and Op — B : and the spheno-
ethmoidal angle (6).

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 247

It may be repeated that the surface of section (cf. Fig. 172)
presents the following points
of importance, viz., N, the
nasion, Pr, the spheno-eth-
moidal junction (the upper-
most limit of which may be
designated the prosphenion),

B, the basion, and Op, the
opisthion : and that the line
from nasion to prosphenion
represents the “anterior base,”
the line from prosphenion
to basion the “ middle base,”
and that from basion to
opisthion the “ posterior base ”
according to the system of nomenclature devised by Cleland.
We have seen that in the process of evolution, the portion repre-
sented by the anterior base of the cranio-facial axis has been
inflected upon that indicated by the middle base : and that the
inclination of the middle to the posterior base has also varied. It
remains to draw the lines representing the several bases and to
measure the angles included by these lines. Thus between the
anterior base1 and the middle base an angle is included which is
called the spheno-ethmoidal angle (cf. Fig. 172, 0). This angle is
regarded as salient upwards and backwards, so that in the
Hominidae its value falls short of 180°. Between the middle
base and the posterior base is the angle known as the foramino-
basal, which is regarded as salient downwards, and thus like the
spheno-ethmoidal angle does not amount to the value of two right
angles (180°) in the human skull.

One angle remains, viz. the spheno-maxillary, included by the
lines drawn from basion and prosthion respectively to the pro-

1 Apropos of this angle, it will be remembered that the determination of the
“anterior base” by the nasion, is attended by the disadvantage that the nasal bones
extend to a very variable degree upon the surface in different skulls : a point more
suitable for determining the anterior end of this part of the cranio-facial axis would
be perhaps the margin of the foramen caecum, as a substitute for the nasion ; but
in view of the inconstancy of this, and of the small probable difference in the
results of measurements, the nasion may well be retained as originally described.

248 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

sphenion. This angle affords a most excellent measure of pro-
gnathism, and is to be preferred before the facial angles measureable
upon the non-sectionized skull. Unfortunately but few com-
parative data for this (the spheno-maxillary) angle exist. The
numerical values of these angles in terms of degrees will be
mentioned in the sequel.

“ The so-called facial angle, in fact, does not simply express the
development of the jaws in relation to the face, but is .the
product of two factors, a facial and a cranial, which vary inde-
pendently. The face remaining the same, prognathism may be
indefinitely increased, or diminished, by the rotation of the
frontal end of the skull, backwards or forwards, upon the anterior
end of the basi-cranial axis1.”

The spheno- ethmoidal and spheno-maxillary angles are asso-
ciated with Huxley’s important research on the cranio-facial axis:
the foramino-basal angle is associated with the name of Turner2.
While omitting detailed descriptions of the angles historically
older, we have already alluded to the work of Daubenton in the
18th century, on the inclination and position of the foramen

Fig. 173. The same specimen as that shewn in Fig. 172, to indicate the angle
of Daubenton (6").

Fig. 174. The same specimen as that shewn in Fig. 172, to indicate the occipital
angles (6 and 6') of Broca.

magnum in the crania of mammals, and the later development of
this subject by Broca, from which we derive the occipital angles
of Daubenton and Broca (cf. Figs. 173 and 174); historically of

1 Huxley, Journal of Anatomy and Physiology , Vol. i.

2 Challenger Reports, Human Crania.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 249

interest also are the researches which gave rise to the invention of
the angles of Landzert, of Virchow, and of Welcker. The facial
angle recently mentioned by Keith1 corresponds to none of those,
nor to the spheno-maxillary angle of Huxley, to which it cannot
be considered superior3.

(4) Measurements of Capacity. From angular measure-
ments we turn to measurements of capacity : such measurements
have been applied to the endocranium and to the orbital cavity :
but the first of these only need detain us here (the capacity of the
vertebral canal of the spinal column being considered in another
connection). The sinrplest way of determining the capacity of the
skull is to plug all foramina and orifices save the foramen magnum,
and to fill the skull with some suitable substance which can then
be withdrawn and measured in a graduated vessel. Experience has
shewn however, that the results are very variable, and that the chief
sources of error are dependent on the nature of the substance used
to fill the skull, the personal equation of the observer, affecting the
tightness of packing both the skull and the vessel in which the
contents of the skull are subsequently measured. To obtain
trustworthy results, therefore, care must be exercised in regard to
these points : of the various materials used, No. 8 shot is perhaps
the best, though peas and various other seeds and even sand have
been used. The shot is always to be poured in through a funnel
of certain dimensions, and the process of shaking the shot into
place and arranging it with a wooden rod are to be made as
uniform as possible. Unsatisfied with the results and in view of
the conditions which exclude fragile skulls from measurement,
certain observers (such as Benedikt in Vienna and Poll in Berlin)
devised a method whereby an india-rubber bag was introduced
into the cavity of the skull and then inflated with water under a
pressure which was made constant in a series of observations.
This is certainly a better method than the older and simpler one,
but has the disadvantage of necessitating somewhat costly appara-
tus, while the possible perforation of the india-rubber bag under
tension by some endocranial spicule of bone necessitates great care

1 Human Morphology and, Embryology , p. 173.

The very important frontal and bregmatic angles, devised by Schwalbe, will be
considered in Chapter xvii.

250 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

in manipulation. At the present time another method of obtaining
a measure of cranial capacity is available and it is one which
depends upon the linear dimensions of the skull. Topinard puts
the matter in the following way. Supposing that one multiplies to-
gether the length, breadth and height of a skull, one obtains a figure
which represents the contents of a parallelopiped having these
dimensions. This figure divided by 2 would give approximately
the contents of the1 sphere that could be contained within this
parallelopiped figure: or if this divisor (2) be mutiplied by 1T75
the volume of an ellipsoid body would result, But in consideration
of the facts that the cranium is neither precisely spheroidal nor
ellipsoidal, and that the thickness of the skull wall has to be
allowed for in estimating capacity, the result is not reliable. An
empirical value for a factor which should replace the figure 1T75
was sought by Broca, who obtained the figure 1T2, and this was
subsequently shewn by Manouvrier to vary in the sexes, 1T35
being the more correct figure for the male, 1T08 for the female
skull. This factor is introduced into the formula,

~ Length x Breadth x Basal Height

Capacity = 2 x 1-138 (or 1-108) '

and is stated by Topinard to be correct to within 4 °/0.

Inasmuch as the total figure is represented by about 1500 c.c.,
the error may thus be as much as 60 c.c., no inconsiderable amount,
but not conspicuously greater than occurs in the old method when
great care is not exercised. It is to be noted too that the formula was
devised primarily for French crania and will almost certainly need
modification for other skulls. Quite recently, a pupil of Karl
Pearson (Dr A. Lee) has resumed observations, and using the
auricular height instead of the basal height, has published for
German and Egyptian skulls, formulae of much greater value and
accuracy than the foregoing. The values of the capacity of crania
will be the subject of further mention in the next chapter.

(5) It remains to consider the method of weighing, and in this
connection it may be mentioned that the skulls, mandibles, and
other bones of various animals and of man have been weighed, the
results tabulated and compared. The value of the results depends

1 Presumably the greatest sphere.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 251

on those comparisons, the consideration of which does not come
within the scope of the present chapter.

We have thus briefly reviewed the fundamental principles of
comparative craniology, and insisted that comparative human
craniology must be based on similar considerations of morphology
to those which determine comparison of human with other crania.
From this we passed to the numerical methods, dealing particu-
larly with those best adapted for recording morphological structure
in a form suitable for comparative studies. We are now in a
position to consider the uses to which such data may be put, after
they have been made and collected according to the instructions
given.

APPENDIX TO CHAPTER X.

CRANIAL DEFORMATIONS.

Cranial deformations are met with in most collections of
human skulls, and as they vary considerably in respect of causation
as well as in appearance, the following remarks are appended with
a view to affording some guidance in the diagnosis of examples of
the cases of most frequent occurrence.

Distorted or deformed crania may be best classified according
to the scheme first devised by Turner, of which the following
is a modified form.

I. Synostotic deformation : this is consequent upon irregu-
larities of cranial development, accompanied by precocious union
of two or more cranial bones.

II. Artificial deformation, consequent on compression applied
in infancy.

III. Pathological deformation ; the result of disease.

IV. Posthumous deformation ; due to the pressure exerted
by the soil surrounding a skull after interment.

I. Synostotic deformation. Synostosis of the cranial sutures
may be either precocious or retarded. In the event of premature
synostosis, some deviation from the normal cranial form is very

252 COMPARATIVE CRANIOLOGY AND CRAN IOMETRY [SECT. C

common, and a general rule has been formulated (by Virchow)
to the effect that premature synostosis is followed by restricted
growth in a direction perpendicular to that of the synostosed
suture. Thus if a longitudinally-directed suture be closed by
premature synostosis, the skull-growth in the transverse or coronal
direction will be checked. Should the coronal or other trans-
versely-directed suture be thus obliterated restriction of growth
in the sagittal direction will ensue.

(a) Scaphocephalus (cf. Fig. 175): probably the commonest
deformation associated with premature synostosis. There may be
an appearance of annular constriction (see under Klinocephalus),
and the specimens are always dolichocephalic, the narrowness
which gives this character being due to restricted growths trans-
versely, in accordance with the law formulated above, following
upon closure of the sagittal suture.

Though scaphocephalus is so often the associate of premature
synostosis, yet this is not always the case, for in many scaphoid
(scaphocephalic) crania, the sagittal suture is not obliterated. Good
examples of this may be seen in collections of crania of Green-
landers, or of Oceanic negroes or aboriginal natives of Australia.
Conversely, the sagittal suture maybe entirely obliterated without
the production of scaphocephalus, so that the foregoing statements
are evidently liable to numerous qualifications and possess a general
significance only.

(b) Klinocephalus (cf. Fig. 17G): when the fore-part of the
sagittal suture is closed prematurely and at the same time the
parieto-sphenoidal suture also disappears, the growth of the skull
is arrested locally, at the sides and top ; this results in the produc-
tion of a depression encircling the skull as though a band had
been tightly applied. A slight degree of this deformity seems to
be very common in female skulls of whatever race. The character
is sometimes referred to as “ annular constriction, and is quite
distinct from the artificial deformation produced by bands, in
which the sutures remain open.

(c) Trigonocephalus (cf. Fig. 177): where the inter-frontal
or metopic suture closes prematurely, there may ensue localised
arrest of transverse growth ; the frontal region will then remain
narrow and stunted in growth, while the posterior parts of the

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY

253

cranium expand normally. The result is the production of a skull
which viewed from above presents a peaked or rostrated appearance
and has been described as triangular or trigonocephalic. It is
worth notice that the suggestion has been made that the skull of
the fossil Pithecanthropus erectus partakes, to a slight degree,
of this character. (Cf. Chapter xvii.)

Fig. 177.

Fig. 175. Scaphocephalus. Fig. 176. Klinocephalus and annular constriction.
Fig. 177. Trigonocephalus. Fig. 178. Plagiocephalus.

(cl) Plagiocephalus (cf. Fig. 178). The skull is asymmetrical.
In typical cases there is closure of part of the coronal suture at
a premature stage : the arrest in growth is then unilateral and the
skull becomes flattened on one side, while in compensation the
opposite side projects. In extreme examples almost a reniform
outline is produced.

254 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT. C

But asymmetry is not always associated with premature syno-
stosis. Slight degrees of deformation of this kind may be possibly
produced in childhood, if the infant lies habitually on one side
rather than the other. Injuries, disease, and pressure of soil
after interment must also be considered in the category of pro-
ductive factors of asymmetry.

(e) Thyrso- or Akro-cephalus (cf. Fig. 179): the bones of
the cranial vault are upraised, so that the height
of the skull is much increased. These crania
are usually very brachycephalic, and the coronal
suture is often closed, while part of the sagittal
(near the bregma), and the basilar sutures may
partake in the synostotic processes

In the foregoing deformations the cranial
capacity is little if at all modified: the central
sulcus (of Rolando) does not bear a constant rela-
tion to the coronal suture considered as its superficial landmark.

II. Artificial deformations: in these, pressure is artificially
applied in various ways and to various regions of the head. Thus
the pressure may be

( /') Frontal : exercised by means of a board, as for example,
among certain N. American Indians ; probably the deformed crania
of Mallicollese, of prehistoric Avars, and Makrocephali of the
Crimea are attributable to a similar cause.

(r/) Fronto-occipital : pressure exercised in front and behind
the head : there are bi-lobed and tri-lobed varieties, in which a rod,
being substituted for a flat surface, indents the young head to
which it is applied. The most striking examples are found among
American aborigines.

(A,) Annular : due to a bandage wrapped round the head :
examples occur in France (Toulouse) and Switzerland as well as
in more remote lands, such as Borneo.

(i) Plagiocephalic : where the compression is unequally
exerted and the deformation is asymmetrical.

( j ) Platybasia : the deformation in which the basis cranii
appears to be thrust up into the cranial cavity: this variety of
deformation is however more commonly associated with defects in

Fig. 179. Thyrso-
ceplialus.

CHAP. X] COMPARATIVE CRANIOLOGY AND CRANIOMETRY 255

the texture of the bones, and thereby enters more fitly into the
next class.

III. Pathological : this group includes many plagiocephalic
and most platybasic forms.

(k) Hydrocephalus : excessive and even expansion of the con-
stituents of the cranial walls; many wormian bones1 2 are commonly
developed to make good the gaps formed along the sutural lines by
the separation of the bones in consequence of the expansion. The
ventricles of the brain are distended with cerebro-spinal fluid, and
the varieties of hydrocephalus have been classified according to
the causes of accumulation of the fluid.

(l) Rachitis (or Rickets) : the frontal bone has a remarkable
appearance : it is unusually prominent in its upper portion : the
term used by French writers is “bombe.”

(m) Other bone diseases produce characteristic deformations.
Among these Congenital Syphilis, Leontiasis ossea, and Acromegaly
are perhaps the most important.

A map (cf. Fig. 180) is appended to shew the distribution of
the practice of artificial cranial deformation geographically.

Fig. 180. The horizontal shading marks the geographical distribution of the
practice of artificial deformation of the skull. The Malay Peninsula should be so
marked in addition to the other regions2.

1 It was probably in such a specimen that the great number (172) of wormian
bones were found, as recorded by Charles A. Parker. Cf. Bolk, Petrus Camper,
Di. n. Afl. 2.

2 Cf. Annandale, Fascic. Malay : 1904.

256 COMPARATIVE CRANIOLOGY AND CRANIOMETRY [SECT/ C

IV. Posthumous deformation is due to the action of the
medium in which a corpse has been interred. Perhaps the most
common effect is the production of plagiocephalus, owing to
pressure being exerted unevenly on the skull. Besides this, every
degree of flattening in almost any plane, may be produced. These
conditions are usually distinguishable from other- varieties of
deformation by the facts that the skull is commonly excessively
fragile, and can rarely be removed intact from the surrounding
earth : moreover the cranial sutures will not be closed by syno-
stosis, except in senile specimens whose age would be indicated
by other characters such as those of the mandible and dentition.

CHAPTEK XI.

THE CRANIAL INDICES, ANGLES, AND CAPACITY.

In the preceding chapter a scheme for drawing up a cranio-
logical description was set forth, and to this was appended a list
of measurements which prove of use in enabling comparisons to be
made more exact than by the method of inspection alone. It was
pointed out incidentally that certain writers disregard, to a large
extent, the numerical craniometrical method. The other extreme
has been reached by such observers as v. Torok1 in Buda-Pesth,
and Benedikt2 in Vienna, in whose contributions to craniology
measurements are detailed in vast numbers. The question at
issue is a fundamental one, and involves the view taken of the
nature of such an organic structure as the cranium considered as a
whole ; that is, whether it is justifiable to apply to its study similar
methods to those in vogue with regard to such bodies, for instance,
as possess crystalline form. The point of view here submitted as
most reasonable regards measurements as of unquestionable utility,
and it is incontrovertible that if measurements are made at all, no
pains are too great to bestow on the method by which they may
be made in a strictly accurate and comparable fashion. At the
same time, when the subject is approached from the point of view
of morphology, and not from that of the science of statistics, one
finds that comparatively few measurements have been so employed
as to provide general conclusions applicable to the wide range of
forms under observation, and for this reason it is believed advisable

1 v. Torok, Grundziige einer systematischen Craniologie, Stuttgart, 1890.

2 Benedikt, Manuel technique et pratique d’Anthropometrie cranio-cephalique,
Paris, 1889.

D. M.

258

THE CRANIAL INDICES

[SECT. C

(except in original researches the results of which may subse-
quently contribute to the progress of science), to limit the number
of measurements to the small number which appears in the list
provided in the last chapter.

When numerical data have been collected, the next natural
step is a direct comparison of the corresponding figures relating
to different examples, and the methods of making such comparisons
are found to be numerous. Before proceeding to the consideration
of these it will be well to complete that part of our subject which
bears upon measurements, and to review the more important
measurements to be made upon other parts of the skeleton than
the skull and also upon the soft tissues and the external form. In
the present connection, therefore, the next subject for consideration
is that of the method of indices, which consists in the comparison
of different dimensions of the same specimen, and the closely-allied
method of moduli.

Indices. The fundamental idea in the construction of an index
is that a single numerical expression shall be so devised as to
yield an “ indication ” of the proportion or relation obtaining
between certain quantities, and in the present subject those
quantities are commonly limited in number to two. The simplest
index is then the fractional value of the arithmetical proportion of
the two quantities ; for example, we may suppose that the breadth
of the cranial part of a skull is to its length as 3:4; the index of
length and breadth will then be f or -75. Such an index is called
the breadth index of a skull, and conventionally it is usual to
express it not as the direct, but as what may be called the per-
centage proportion, so that in the foregoing instance the index
would be '75 x 100 or 75, and the index would for similar instances

be derived from the formula I = yX 100. The number 75 thus

imparts an idea of the proportions of maximum breadth and
maximum length of the specimen, which may then be in this
manner clearly contrasted with, for instance, a second skull having
as index the number 90. Moreover, we must not forget that the
indication is one of proportion only, and that in the two instances
quoted, the actual value of one of the two dimensions compaied
by means of the index might be identical in the two skulls, and

THE CRANIAL INDICES

259

CHAP. Xl]

that the difference in the indices would be then due to the
difference obtaining in the other dimension. In the next place it
will be remarked that the quantities compared are rectilinear
measurements of breadth and length, measurements approximately
in the same plane : but it is not necessary that the quantities
compared should be of the same kind though it is advisable that
this should be so : for instance, an index might be obtained from
the proportion borne by the number representing the weight of
the skull to the figure representing its length, or to that repre-
senting its circumference or its cubic capacity : or the proportion
of the weight of the brain to the stature of an individual might
be expressed as an index : nor is it necessary as indeed follows
from the last sentence, that the measurements should be made in
one plane ; for an index may represent the relation of height to
length (or breadth) of a skull, just as it has been shewn to be
capable of expressing the proportion of breadth to length.

The indices in common use may now be enumerated as
follows : —

1. The Cephalic or Breadth Index, by which cranial breadth
and length are compared.

2. The Altitudinal or Height Index, by which cranial height
and length are compared.

3. The Alveolar Index, by which the lines from basion to
nasion, and to prosthion respectively, are compared.

4. The Nasal Index, whereby the width and the height of the
nose1 are expressed.

5. The Facial Index, by which the height and breadth of the
facial part of the skull are compared.

6. The Stephano-zygomatic Index, by which the inter-ste-
phanic and the bizygomatic diameters are compared.

Of other indices a great number have been used in craniometry,
but only one will be here mentioned. The Orbital Index compares the
height and width of the orbital aperture, but its range of variation
is too great to render accurate information in most instances. So
many records of this index exist, however, that at least it must be
mentioned here. Lastly, and as regards the morphological value

1 The nasal aperture of the cranium.

17—2

260

THE CRANIAL INDICES

[SECT. C

of indices, it must be pointed out that historically the oldest is the
Breadth Index, devised by Retzius for the purpose of expressing
the proportion of breadth and length : but that it cannot be said
that more than general morphological information is conveyed by
this index. Flower, on the other hand, conceived the idea of
referring all dimensions to one standard, selected on morphological
grounds, and actually the length of the cranio-facial axis. In this
scheme every cranial dimension might thus contribute to the
formation of an index with a common denominator. As a matter
of fact, we have retained but one such index, the Alveolar, or
Prosthionic Index, which, as will be seen on reference to its
description, expresses the length of the basi-prosthionic, in terms
of the basi-nasal line, the latter being representative of the cranio-
facial axis. In the next place, we come to the consideration of
classifications based upon the numerical values of indices. Our
example contrasted skulls in which the indices of breadth and
length were 75 and 90 respectively : crania are found to provide
indices (of breadth and length) of any value from about 56 to 95,
in specimens that are not artificially or pathologically distorted. So
for the Height and other indices a considerable range of variation
occurs. With regard to the Cephalic Index, it has been conven-
tionally agreed to apply to skulls providing this index with a
smaller value than 75, as dolichocephalic, for such skulls as possess
a maximum transverse cranial diameter less than thi’ee-quarters
of the maximum length give the appearance of elongation : should
the figure be 75 or any higher figure up to and including 80, the
designation of the example is mesati-cephalic (of mean proportions),
and from 80'1 upwards the term applied is brachy-cephalic, the
form then appearing short in comparison with the foregoing.
Proceeding in this manner the following table may be drawn up,
and a few words of explanation will next be added to each of the
several indices : reference should also be made to the general de-
scription. (Cf. p. 232.)

CHAP. Xl] THE CRANIAL INDICES

261

Index

1. Breadth :

Maximum breadth x 100

Maximum length

2. Height:

Basal height x 100
Maximum length

3. Alveolar :

Basion to prosthion x 100
Basion to nasion

4. Nasal :

Nasal width x 100
Nasal height

5. Facial :

Nasion to prosthion x 100
Bizygomatic breadth

6. Stephano-zygomatic :
Inter-stephanic breadth x 100

Bizygomatic breadth

7. Orbital :

Orbital height x 100
Orbital width

Classification

Nomenclature

General indication

Below 75

Between 75 and 80
Above 80

Dolicho-eephalie

Mesati-eephalic

Brachy-cephalic

Variable, and dependent
on Age, Sex, and Race.

Below 72

Between 72 and 77
Above 77

Tapeino-cephalic

Metrio-cephalic

Akro-cephalic

In general, the lower the
index, the lower the
cranial form.

Below 98

Between 98 and 103
Above 103

Orthognathous

Mesognathous

Prognathous

The greater the index, the
greater is the projection
of the jaw, and conse-
quently the more ape-
like is the countenance.

Below 48

Between 48 and 53
Above 53

Leptorrhine

Mesorrhine

Platyrrhine

Lower forms of crania
have the greater indices.

Below 50
Above 50

Chamaeprosope

Leptoprosope

Generally the lower forms
have the lower indices.

Below 100
Above 100

Phaenozygous

Cryptozygous

In the lower cranial forms
the index is below 100.

Below 84

Between 84 and 89
Above 89

Microsemie

Mesosemic

Megasemic

Indication variable : gene-
rally speaking, lower
human forms have lower
indices.

The Breadth or Cephalic Index: the description and defi-
nition of this index have afforded a means of appreciation of the
information which it yields. It is unfortunately not applicable to
the crania of the Simiidae with results strictly comparable to those
obtained from human skulls (for in the Simiidae bony ridges
modify the form of the cranial bones to a very considerable degree) ;
but there is a certain indication that the skulls of Orang-utans tend
towards the brachy-cephalic class, those of Gorilla to the dolicho-
cephalic category (and with the latter are associated many examples
of the Cercopithecidae), while the Chimpanzee may be considered
to represent the intermediate group. Thus, taken by itself, no
absolute indication of morphological inferiority is provided by a
low, moderate or high figure representative of the Breadth Index.

262

THE CRANIAL INDICES

[SECT. C

When the comparison is restricted to human crania, the results
are a little clearer. The chief modifying influences may be summed
up as dependent upon Age, Sex, and Race. The skull-form in the
pre-natal (foetal) stages tends on the whole to brachy-cephaly (see
Gonner : ref. Chapter vn. p. 162), and a comparison of Froriep’s
figures for this index in skulls of infants and adults in the Wiir-
temberg collection points to the same conclusion. In regard to sex,
a good example is that yielded by the almost extinct aborigines
of South Africa, the Bush natives: the female skulls are here
mesati-cephalic, the male crania are dolicho-cephalic on the average.
Finally, there is no doubt that in the darkly coloured races (including
human beings on the lowest known level of culture) the pre-
dominant form is dolicho-cephalic, though at the same time this
character is again found among certain white stocks inferior to
none in intellectual ability.

A table lately compiled by Deniker gives the following figures
as representing the extremes of variation of the average cephalic
index in human skulls :

73 Fijians : average cephalic or breadth index, 67‘2

41 Lapps : „ „ „ „ „ 85 ;

and lastly, that the increase in breadth of the skull, which is the
prime cause of the production of the brachy-cephalic proportions, is
due to general expansion of the cranial contents, has just been
very ingeniously demonstrated by Professor Arthur . Thomson,
whose model (devised for this purpose) is described, and repre-
sented in a private publication (Clarendon Press, Oxford), as well
as in the Journal of the Anthropological Institute.

The Altitudinal or Height Index. Considerations similar to
those which apply to the last index also prevent the use of the
Height Index as a means of accurate comparison of the skulls of
Hominidae and the Simiidae. When we again restrict observation
to the former, we find that, as a general rule, the Height Index
varies with the Breadth Index directly, so that where the skull is
very elongated, then the expectation would be to find a small
figure representing the Height Index (with the corresponding
denomination of tapeino-cephalic). This tendency is shewn by a
study of Froriep’s figures for the indices of crania in the Tubingen

THE CRANIAL INDICES

263

CHAP. Xl]

collection : in children’s crania, the average index is 75‘2 ; with the
increase in dolicho-cephaly as maturity is approached the height
index falls in value, till in adults it averages 72’9. As regards
the influence of sex no definite statement is possible, but in respect
of racial influences, the elongated skulls of darkly pigmented races
yield the best examples of this relation, for such it is, between the
breadth and height of the cranium, but the tendency appears
to be otherwise independent of race. Striking exceptions to
this general statement occur among certain of the Oceanic negro
races, in which the skull being often narrow, and at the same time
vertically expanded , is described as hypsi-steno-cephalic in form . As
extreme examples there may be quoted the figures given by
Topinard, representing average values, though the number of
observations in each case is not stated.

Pre-historic French (Ca verne de l’Homme mort) : 68‘8 : tapeino-
cephalic.

Javanese : 79 : akro-cephalic.

The Alveolar Index enables direct comparisons to be instituted
between the skulls of various mammals. In this index the amount
of projection of the maxilla beyond the cranial base is measured, by
the comparison of the line drawn from the basion to the extreme
anterior maxillary point (prosthion), with the line representing the
cranio-facial axis. We may here confine our attention to the
families Simiidae and Hominidae : and as examples of the value of
the index, representative figures may be quoted (a) for the skulls
of Gorilla1, 139-7(2) Orang-utan 155-3(1) ; Chimpanzee 128-8(1).
(6) for skulls of aboriginal natives of Australia the range is from
about 96 to 108. Within the limits of the Hominidae, we have to
consider first the- influence of age ; and in this connection the
following figures are illustrative.

(a) for new-born children (European) : 93‘52(2).

1 The figures in brackets represent the number of examples whence the figures
are drawn.

2 The question of the prognathism of the infant at birth is a subject upon which
diverse views are held (v. supra Chapter vii. p. 172). In point of fact, the teeth
within the substance of the foetal and infantile maxilla so modify its form as to
render comparison with the fully developed maxilla quite fallacious. The evidence
of this index is however more reliable than that provided by the facial angle, and
the foetal or infantile skull is essentially orthognathous.

264 THE CRANIAL INDICES [SECT. C

(b) For adult Europeans (average from Flower’s Catalogue1)
96-2'184>.

In the second place, the sexual factor has to he considered, but
herein no important differences have been observed in the skulls
of Eui’opeans, though an indication is given of the more pronounced
maxillary projection in female crania. This indication is more
definite in the case of the aborigines of Australia, as evidenced
by the following (average) values of this index; — aborigines of
Australia, average for males lOO^*73' ; for females, 103T(33).
Thirdly, the influence of race must be taken into consideration,
and the figures which follow illustrate the differences obtaining in
different racial types. Examples of these may be given in this
place. Ancient Egyptians (average quoted in Flower’s Catalogue):
95(22). African negroes (average quoted in Flower’s Catalogue):
104,4(361.

The Nasal Index also affords a direct means of comparison
of the skulls of various mammals. Again restricting ourselves to
the Primate families Simiidae and Hominidae, the following data
illustrate the character and value of this index in each case.

Nasal index in Simia, about 50.

Average nasal index in Man (British), 46.

Though the figure representing the index in the ape is higher,
and the nasal aperture thus shewn to be wider relatively to its
height than in Man, the comparison is not very exact, owing to the
length of the nasal bones being reckoned in the height-measure-
ment, and the absence of a nasal spine in the Simiidae. Factors
are thus introduced which, although a comparison may be made,
preclude accuracy. If, instead of the nasal index as defined, we
consider the index of the aperture alone we find the following
figures. Gorilla, 73 : Europeans (Dutch), 63‘7 ; herein the differ-
ences are further emphasized. But this index is not much more
satisfactory than the ordinary nasal index, on account of the
ambiguity in the indices of the apes consequent on the absence
of the nasal spine.

Within the family Hominidae the influence of age must be
taken into account : the value of the index in the new-boni

i Of the Museum of the Royal College of Surgeons in London. The figures in
brackets represent the number of examples whence the figures are drawn.

THE CRANIAL INDICES

265

CHAP. Xl]

(European) infant is about 62*9 (2), and this, compared with the
figure quoted above for adults, shews the wider character of the
infantile apertura pyriformis nasi.

When the influence of sex is considered, the following figures
may be quoted: average European (German) male, 51*9 (Froriep);
female (German, Froriep), 441. But as Topinard remarks (El.
d’Anth. gen., p. 293), the data are too conflicting to admit of a
general statement.

Lastly, the influence of race is clearly shewn by the following
results collected by Deniker.

Average value of the nasal index of the skull.

(a) for Eskimo1, 42*2 <46), (individual examples may yield
figures as low as 32*7).

( b ) for South African negroes, 61*7 (15).

The Facial Index. By means of the facial index skulls are
divisible into two groups, viz., narrow-faced (lepto-prosopic), and
broad-faced (chamae-prosopic) types. The comparison with animals
is unsatisfactory, owing to the modifications in facial length asso-
ciated with prognathism and its converse, which may more than
counterbalance variation in the bizygomatic breadth of the face.
Making allowance for this, we note that the skull of an example
of the Simiidae gives as the value of this index the figure 82*3,
with which we may compare the figure 54, representative of
English (Saxon) crania (Horton-Smith). The gap separating the
Hominidae from the Simiidae is thus very distinct. Turning to
the differences within the human family, the following data are
illustrative: European males ( v . supra), 54<20) : females, 45*5 (2).
The latter figures are taken from Kollmann (“Bericht der XXIX all-
gemeinen Versammlung in Braunschweig,” Archiv fur Anthropo-
logie : Correspondenz Blatt, S. 121). But though the female skull is
generally narrower, the difference has not yet been worked out on
an appropriate number of skulls. As regards the age-factor, the
indices in two human foetuses at the end of intra-uterine existence
are 39*3 and 39*4 respectively. These figures, compared with those
for adults, are expressive of the small proportions of the face-breadth
in the infant and foetus, just as the corresponding figures illustrate

1 The figures in brackets represent the number of examples whence the figures
are drawn.

266

THE CRANIAL INDICES

[SECT. C

the limit of growth in facial breadth in the Hominidae as compared
with the Simiidae. It will be remembered that this facial growth
is expressed by the bizygomatic breadth, which is related to
prognathism, and the mass of the temporal muscles.

Turning lastly to racial differences in this index, we may
compare the average value for twenty European crania, viz. 54,
with that of eight Australian aborigines, viz. 51, the latter figure
one might have expected to be larger; and that this is not the
case is due to prognathism, here associated with great facial
elongation, without a corresponding degree of facial breadth.
In the Eskimo cranium on the contrary, growth in breadth
predominates, and the index is accordingly 55'9 (Ass^zat).

The Stephano-zygomatic Index (fronto-zygomatic index of
Topinard) is not strictly determinate for other skulls than those
of Hominidae. Within the limits of that family Topinard has
worked out the results in reference to the modifying effects of age,
sex, and race. With regard to these three factors, the following
figures quoted by Topinard {El. g&n. cl’ A. p. 936) are of interest.
Europeans: infants (in the first six months) 116'2: adult males
(Dutch) 907 : adult females (Dutch) 94'6 : male aborigines of Fiji,
73'7. The respective influences of increase in age, of the male
sex, and of the primitive nature of the race in contributing to the
production of a small numerical value in this index, are thus most
clearly shewn.

The Orbital Index. As regards the comparison of Hominidae
with the other families of the Primates, it must be admitted that
no satisfactory results have been arrived at : and even within the
limits of the Hominidae, the range of variation of this index is so
great that it has been accorded quite a subsidiary place in the
list of selected indices. Among the Simiidae the form of the
orbital aperture varies (cf. Fig. 52) with the genus ; but while the
difference in detail between the Orang-utan and the African
Anthropomorphous apes is marked, the orbit is proportionately
higher in all the Simiidae than in the Hominidae. Among the
latter, the proportions of the orbit are much affected by the
prominence and degree of development of the supra-oibital lidges.
hence the influences of age, sex, and race must all be taken into

CHAP. Xl] THE CKANIAL INDICES 267

consideration. As regards the former, dried skulls of foetuses and
still-born infants often provide a paradoxical result ; for instance the
average index from two examples is 73-5, which is a far lower figure
than would have been expected, and is to be attributed to some de-
formation having occurred during the desiccation of the specimens.
With regard to the differences due to sex, Broca1 has published
figures to shew that this amounts to as much as 31 °/o of the total
range of racial variation, as examples of which, there may be cited :
Torres Straits Islanders : males, 83 ; females, 90. The variations
as regards race are from 98, which is the average value in ancient
Peruvian (Aymara) crania, to 7 5*6, for aborigines of Tasmania.
The high numerical value of this index among the yellow races,
including Chinese, Polynesians, Javanese, Indians of North America,
ancient Peruvians, and Eskimo, is remarkably constant. The
opposite extreme is provided by the dark-skinned races of Oceania.
It thus appears that the vertical height of the orbit is proportion-
ately great in the yellow-skinned races, and in females of whatever
race. The white races occupy an intermediate place in this respect.
The African negroes shew much variety, and the black races of
Oceania, in whom the brow ridges are strongly developed, present
proportions in which the vertical height appears diminished in
contrast with the preceding examples. As regards the crania of
infants, and from the results of observation made in accordance
with the German method, which differs but very slightly from that
described in the text, the crania of infants possess on the average
an orbital index (88'5) higher than that of the adult of either sex
(85' 5 for males, 86'4 for females)2.

As regards the relation between the proportions of the orbital
cavity and the range of human vision, the following note, taken
from Seggel’s work in v. Graefe’s Archiv (xxxvi., Abth. n.), is of
interest. Stilling (Congress of Ophthalmologists, 1888) found
myopia common in connection with a low (i.e. flattened) orbital
aperture, and suggested that these proportions, together with the
direction of the tendon of the superior oblique muscle and the
pressure exercised by both oblique muscles, would cause antero-

1 Broca, L'indice orbitaire, Paris, 1876.

2 Cf. Froriep, Catalogue of the Tubingen Collection, Archiv fur Antliropoloqie,
1902.

268

ANGULAR MEASUREMENTS

[SECT. C

posterior elongation of the eyeball with consequent myopia.
Opposed to this is the fact that in Esthonian scholars, who have
broad faces and “low” orbits, the percentage of myopia is less than
in Europeans in general (Pymsza, “Inaugural Dissertation” Dorpat,
1892).

In terminating the present chapter, a few remarks may be
added on the subject of the classification of crania according to
the evidence provided by the angular measurements defined in
Chapter x., and of the cubical contents or capacity of the brain-case,
with brief mention of some methods of classification dependent on
observations on the weight of various bones, etc.

Angular measurements. As a means of estimating the pro-
jection of the maxilla, the angle known as the spheno-maxillary,
as defined in the preceding chapter, is the most accurate of all the
angles which may be described as facial angles. Hitherto, data
relating to the value of this angle in various skulls have been
insufficient to provide a detailed classification, but the following
list shews how the Hominidae are by its means clearly differ-
entiated from other Primates and Mammalia.

The Spheno-maxillary angle (measured on the mesial
sagittal cranial section).

Dog (W.L.H.D.). 162°.

Cercopithecus monkey „ 119°.

/Simia (orang-utan) „ 146°.

Simiidac -Gorilla „ 125°.

[Chimpanzee „ 121°. (Cf. Fig. 181.)

[Aboriginals of Australia (av. of 7) — 92° 20'. (Cf. Fig. 182.)
Hominidae •! (W.L.H.D., Turner, et alii).

(Europeans (av. of 2, W.L.H.D.). 75° 30'. (Cf. Fig. 183.)

Huxley’s figures (viz. 99° for a Melanesian, and 91 for a Tartai
skull) are very closely but not absolutely comparable : for Huxley
drew his anterior line through the akanthion, a less fixed point
(morphologically) than the prosthion, which was that used in the
foregoing measurements. The latter indicate that a gradual
decrease occurs in the value of the spheno-maxillary angle in
the evolution of the European cranial type. Huxley suggested
a classification based on the slightly different maxillary angle
measured by him, in which orthognathous crania, possessing an

ANGULAR MEASUREMENTS

269

CHAP. Xl]

angle of less than 95°, are distinguished from crania in which the
angle exceeds 95°, and which are to be called prognathous; and
the same writer records an example of a human skull in which the
value of this angle attained 110°.

Fig. 181. Tracing of the skull of a young Chimpanzee bisected in the median
sagittal plane (Mus. Zool. Cant.). In this, and the two following illustrations the
following indications are provided.

Op : the opisthion.

B : the basion.

P : the prosthion.

N : the nasion.

Pr : the prosphenion.

T : the line tangential to the dorsum ephippii.

R : the line perpendicular to the plane of the foramen magnum (Op. B).

Br : the bregma.

L : the lambda.

I : the posterior occipital point.

The lines Pr. P. and B. P. include the spheno-maxillary angle Pr. P. B.

The lines Pr. B. and Pr. N. include the spheno-ethmoidal angle B. Pr. N.

The lines Op. B. and B. Pr. include the foramino-basal angle Op. B. Pr.

With this and the two following figures should be compared, Figs. 4, and 74 to
81 inclusive.

The spheno-maxillary is thus by far the most important
angular measurement by which prognathism can be represented.
Owing however to the historical interest of the angle of Camper,
and the large number of data accessible for the angle of the
Frankfort agreement, a few words must be now devoted to their
further description.

Br.

Fig. 1H2. Tracing of the skull of an aboriginal native of Australia, bisected
in the median sagittal plane (Mm. Aunt. Gant.). The indications are the same as
those in Fig. 181 (q.v.) with the following additions. G. the Glabella. W. the
middle clinoid process (the latter point determines Welcker’s angle).

Fig. 183. Tracing of the skull of an European,
bisected in the median sagittal plane (Mas. Anat.
Cant.). The indications are similar to those in the
two preceding Figures.

ANGULAR MEASUREMENTS

271

CHAP. Xl]

Camper’s facial angle. No classification has been based
upon the values provided by the angle of Camper in the Mam-
malia or within the family Hominidae. The following figures
are taken as examples from Camper’s original description.

In a small monkey (fam. Cercopithecidae) 42°.

In an adult Simia (orang-utan) 47°.

In a young Simia 58°.

In a negro 70°.

In a Calmuck 70°.

In a European 80°.

To this list Camper’s remarks may be appended : “ It follows
from hence that the facial line has in nature a maximum
and a minimum from 80 to 70 degrees (for Man). When
the maximum of 80 degrees is exceeded by the facial line, it is
formed by the rules of art alone; and when it does not rise to
70 degrees, the face begins to resemble some species of monkeys.
...If the projecting part of the forehead be made to exceed the
100th degree, the head becomes misshapen, and assumes the
appearance of the hydrocephalus or watery head. It is very
surprising that the artists of ancient Greece should have chosen
precisely the maximum, while the best Roman artists have limited
themselves to the 95th degree, which is not so pleasing.. . .The two
extremities therefore of the facial line are from 70 to 100 degrees,
from the negro to the Grecian antique; make it under 70, and you
describe an ourang or an ape: lessen it still more and you have the
head of a dog.” {Op. cit. p. 40. Cf. p. 244 supra.)

The Frankfort facial angle. The classification based upon
the numerical value of the Frankfort angle is threefold ; the
three groups being as follows: —

The angle is less than 83°: prognathous1.

The angle is between 83° and 90°: orthognathous.

The angle is above 90°: hyper-orthognathous.

As illustrative of the value of this angle in classification the
Simiidae may be compared with the Hominidae.

The average value of the angle in a series of ten orang-utans

1 Care must be taken not to confound this with the terminology of the alveolar
index (v. nupra, p. 261).

ANGULAR MEASUREMENTS

272

[sect. c.

was found to be 46° 6' (Waruschkin)1, the corresponding figure for
human crania being about 86° 9' (Froriep).

Within the Hominidae, the influence of age must first be taken
into account. From the remarks (cf. footnote, p. 263) made in
connexion with the alveolar index, it would be in accordance with
expectation to find a large facial angle in the skulls of infants:
and female crania should provide a smaller angle than male crania.
Froriep’s observations2 fully bear out these expectations, for the
figures provided are as follows.

Angle of the Frankfort agreement,

(a) average value in infants and children up to years: —
88° 30'.

( b ) average value in adult females: — 85° 39'.

( c ) average value in adult males: — 86° 9' (as above).

The Spheno-ethmoidal angle. The following list contains
examples of the values of the spheno-ethmoidal angle as measured
in a number of skulls.

Dog (W.L.H.D.). 231°.

Cercopithccus monkey „ 172°.

(Simia „ 202°.

Simiidac ^Gorilla „ 158°.

(Chimpanzee „ 168°. (Cf. Fig. 181.)

jAboriginal Australians (av. of 2) 153°. (Cf. Fig. 182.)
Hominidae |Europeans (av_ of 2), (W.L.H.D.) 138°. (Cf. Fig. 183.)

Huxley records 142° in a Tartar and also in a Melanesian
skull.

The figures demonstrate the gradual diminution of the
numerical value of the angle, and the consequent flexion of the
cranio-facial axis as the human type is approached.

The Foramino-basal angle. For this angle the following
figures were obtained: —

1 Archiv fur Anthrop., Bd. xxvi. “Ueber die Proiilirung des Gesichtsschiidels,”
p. 394 : an Orang-utan skull at Cambridge provides an angle of 40° ; Waruschkin
(op. cit.) gives 58° 5' as the mean value from 4 crania of Gorilla, and 66° 7' as the
value in a Chimpanzee skull : pp. 394, 397.

2 Catalogue of the Tubingen collection, Archiv fur Anthropologic, 1902.

CHAP. Xl]

CRANIAL CAPACITY

273

Dog

(W.L.H.D.)

108°.

Cercopithecus monkey

147°.

( Simia

142°.

Simiidae. -j Gorilla

120°.

l Chimpanzee

133°. (Cf. Fig. 181.)

( Melanesian (1)

(Huxley)

147°.

Hominidae. -j Aboriginals of Australia(2)(W.L.H.D.)

146° 30'. (Cf. Fig. 182.)

( Europeans av. (2)

149° 30'. (Cf. Fig. 183.)

The indication of the gradual opening of the angle, with
consequent increase in its numerical value, is clearly shewn by
inspection of the whole series, but the details of transition are not
all so definitly indicated as in the case of the preceding angle.
The foramino-basal angle is thus to be used in comparisons of
the Hominidae and Simiidae with other families and other Orders,
rather than for the comparative study of various members within
the limits of those two families.

Cranial Capacity. The cranial capacity of the smallest
normal (adult) human individual is so superior to that of the largest
member of the remaining families of the Primates that a com-
parison is hardly possible. It seems as if 900 c.c. were the inferior
limit of capacity (in adult Hominidae) compatible with normal
mental development, and the highest figure on record for the
capacity of the cranium of any other primate animal is 573 c.c.
for an adult Gorilla1.

Within the Hominidae, the influence of age is of course very
evident, the cranium of the newly born child containing about
415 c.c. (Broca quoted by Topinard El. g6n. d’Anth. p. 642), and at
the age of three months 546 (Broca loc. cit.). With these may be
compared Broca’s figures for adults in which the sexual factor is
evident, viz.: for males 1559 and for females about 200 c.c. less.

Finally the racial factor is also distinct, and the range of
variation is from an average capacity of about 1550 to 1600 c.c.
(in the white and yellow races), to about 1250 c.c. in the dark-
skinned Andamanese dwarfs.

The preceding remarks refer to determinations made with
the use of shot, sand, or other material with which one skull

D. M.

1 Quoted by Keith. Journ. Anat. and Phyx. Jan. 1895.

274

CRANIAL CAPACITY

[SECT. C.

is filled, the contents being then poured out and measured. It is
here appropriate to add a short account of the results of the
investigations undertaken by Dr A. Lee (Phil. Trans. 196 A.
1901) with a view to the determination of the figure representing
the capacity in cubic centimetres, from the values of three
dimensions viz.: the length, breadth and height of the skull. In
the first place, the combination of length, breadth and auricular
height was found to give closer results than that of length and
breadth with the basal height. Secondly, and this is in opposition
to the view held by Boas (“ The Cephalic Index.” The American
Anthropologist, Vol. I. N.S. 1899), the foregoing combinations are
both preferable to the cephalic index, or the horizontal circum-
ference of the skull for arriving at the closest approximation to
the value of the cranial capacity. In the third place, while no
less than nine formulae are provided, two in particular (Nos. 8 and
9, Lee, op. cit.) are recommended, and it is pointed out that
theoretically it is in these determinations better to use one good
formula, than to strike the mean of the results of several less
accurate formulae. Of those specially recommended, No. 8 seems
to provide the smaller probable error and is therefore given here ;
while No. 9 is appended as indicating the latest result of the use
of the modulus derived from the multiplication together of length,
breadth, and height. Moreover two other points must be noticed
in connection with these formulae. In the first place, they are
derived from data provided for German skulls, data for English
crania not being available for the purposes of calculation: the
formulae would therefore probably need slight modification for
application to English or other crania, the modification being
greater the less nearly the race was allied to the Germans.
Secondly, different formulae apply to male and female crania,
so that we find :

Formula (8). For German male crania

C1 = 7-384 1. + 10-898 b. + 5-228 h. - 2094-31.

For German female crania

C = 7-065 1. + 10-126 b. + 4828 h. - 1902-02,
and the second formula described may be appended, as follows :

1 C = capacity of skull in cubic centimeters.

CHAP. Xl]

CRANIAL CAPACITY

275

Formula (9). For German male crania

C = -000332 (1. x b. x h.) + 415-34.

For German female crania

C = -000383 (1. x b. x h.) + 242-19.

But as it is not unlikely that investigations may be directed
to races not nearly allied to either the Germans, or to the Ainus
for whom formulae have been published, Dr Lee gives a formula
for general use, the accuracy of which will necessarily be less than
when the German and Ainu formulae are used for Germans or
Ainus, or for closely allied races respectively. These general
formulae are as follows:

Formula (10). For males (negroes were excluded in calculating
this formula)

C = -000365 (1. x b. x h.) + 359-34.

Formula (11). For females (negroes were excluded in calcu-
lating this formula)

C = -000375 (1. x b. x h.) + 296-4.

Again where measurements of the heads of the living persons
only are available, the closest approximation is arrived at by the
use of Dr Lee’s formula (14) viz.
for males,

C = -000337 (1. - 11) (b. - 11) (h. - 11) + 406.01,
for females,

C = -000400 (1. - 1 1) (b. - 1 1) (h. -11) + 206-6.

The remainder of the paper whence the foregoing extracts
have been made, contains some most valuable results as regards
the relation of capacity to brain weight.

Comparative weights of various parts of the skeleton.

Recent researches by Messrs Manouvrier, Papillault and Mac Curdy
have shewn that the weight of the skull only varies in a vei-y
general way, as for example with the total mass of the skeleton,
and also with the amount of the cranial capacity. (Cf. Mac Curdy,
“ Indices ponderaux du crane.” Bull, de la Soc. d'Anth. de Pans,
1897.)

With regard to the latter relation, the researches of Manouvrier

18—2

276

CRANIAL WEIGHT

[SECT. C

are very suggestive. The expression used as a means of com-
parison is the relation of the weight of the cranium to its capacity,
the latter being considered as equal to 100. It will be noticed
that this relation involves the comparison of two quantities
(weight and volume) not strictly comparable. The results are
however quite instructive. In the first place, the Simiidae and
Hominidae are distinctly demarcated from one another. In
Gorillas, the skull weight is represented by figures from 132
to 179‘7, when the corresponding capacity is represented by 100.
These figures (132, 179 7) may be called the cranio-cerebral
indices, and we thus have

Gorilla:— 132 to 179 7.

Man: — 41-4 to 48-2.

Within the Simiidae the influence of age is marked as
follows:

Young Chimpanzees: — 60-4.

Adult Gorillas ( v . supra): — 132 to l79-7.

Within the Hominidae the same influence is shewn in the
following way: —

New-born infants: — 12.

Child of 3 years:— 19-7.

Children of 7 to 15 years: — 208 to 34'8.

Adults ( v . supra): — 41 '4 to 48’2.

While the factor of sex is also influential, as shewn in the
figures: — Males 41 -4. Females 40T.

Turning now to considerations of race, we may note the
following data.

Europeans (males): 4T4. Females: — 40T.

Negroes (males): 46-4. Females: — 45‘9.

The aborigines of Melanesia provide on the other hand a
discrepant result1.

Lastly, in all the foregoing instances allowance must be made
for the factor of mass or bulk, as is indicated by the comparison of
the indices in a giant: 64‘2: and a dwarf: 44Y.

1 Skulls in the Cambridge Museum give results as follows.

(1) an Eskimo skull. 27’7 (1882).

(2) a Polynesian skull. 38'9 (1814).

(3) a Bushman skull. 44T (1744).

The Nos. in brackets are those of the Catalogue.

CRANIAL WEIGHT

277

CHAP. Xl]

So that this index yields the following series in order of
increase of weight in comparison with capacity:

Hominidae.

'1.

.3-

5.
.6.
7.

Infant.

Woman.

Man of small stature (or bulk).

Man of tall stature (or great bulk).
Primitive Man.

(Microcephalous Man — pathological).
Simiidae.

Interesting researches by Manouvrier also shew the relations
between the weights of the skull and of the femora in different
members of the Simiidae and Hominidae. Thus in the former,
if the Gorilla be considered, the sum of femoral weights is to the
cranial weight as 143 to 100 in males, and 107 to 100 in females.
The former figures (143 and 107) may be called the cranio-
femoral indices of these animals. Among the Hominidae, the
influence of sex is predominant, and quite obscures those of age
and race: this influence is shewn to be really due to the difference
in bulk obtaining in the two sexes, and within the limits of either
sex the same influence (of bulk) is felt. As examples, the
following may be quoted. For males of various races, the cranio-
femoral index is 123, for women 87. But to shew how important
the factor of bulk is, the value of this index (132) in a giant may
be contrasted with its value (49) in a dwarf. Within the two
sexes finally, 81 °/0 of men possess a cranio-femoral index greater
than 100 (that is the femur is heavier than the skull in 81 °/o)>
whereas in women, only 17 °/0 possess a femur which is heavier
than their skull. The influence of bulk is again to be called in
evidence, as responsible for these phenomena.

The capacity of the vertebral canal. The relation of the
cranial capacity to the capacity of the vertebral canal is the subject
of a paper by a distinguished anthropologist, Professor Johannes
Ranke of Munich (cf. Bastian’s Festschrift. Camb. Univ. Libr.
MH. 32.4). The research shews that the proportion between the
contents of the vertebral canal to those of the skull is not greater,
i.e. is not more simian (or primitively eutherian) in the black
than in the white races. Indeed the opposite relation would

278

CRANIAL WEIGHT

[SECT. C

almost seem to obtain. Ranke rejects, as crude in conception, the
comparison of brain weight and body weight as a test for the
evolutionary status of Man, but it may well be doubted whether
Ranke’s substitution of the comparison of the respective capacities
of vertebral canal and cranial cavity, is preferable to Dubois’
improved method of comparing brain and body-weights, and then
correcting for absolute bulk, species, etc. (Cf. Dubois, “Uber die
Abhangigkeit des Hirngewichtes etc.” Archiv fur Anthropologie,
Bd. xxv. Heft. 4; “Sur le rapport du poids de l’encephale etc.”
Bull, de la Soc. d’A. de Paris. T. 8; Sdr. iv; Fas. 4, 1897.)

Among other points, Ranke notices the “progressive” condition
obtaining in the new-born infant (but a warning must be entered
against laying too great stress on the character in the new-born).
Negroes, as has been remarked, occupy a position higher than
white men. Among the latter, males are “higher” than females,
in contravention of Bischoff’s assertion that the female brain is
relatively greater than that of the male. Lastly, among the
Simiidae, and considering the Orang-utan (Simia) in particular,
here, as among white Hominidae, males occupy a higher place than
females. Some of Ranke’s figures are here appended.

Percentage value of the capacity of the vertebral canal; in
terms of the cranial capacity; the lower the figure, the greater
will be the preponderance of cerebral development.

I. Hominidae. A. White races.

New-born infant: 2’70.

Adult males (av. 2): 8‘41.

Adult female: 9*21.

B. Negro races.

Male (av. 4): 7-69. (One was a dwarf individual, however).

II. Simiidae. Orang-utan.

Male (av. 2): 1873.

Female (av. 2): 22*19.

III. Sheep: 77.32.

Cow: 146 72.

IV. Crocodile: 720.

CHAPTER XII.

COMPARATIVE OSTEOLOGY.

From the cranium, we now pass to the other parts of the
skeleton, considering next in order, as is natural, the vertebral
column, of which the several regions will be reviewed in sequence.

The distinctive features of the cervical spinous processes in
the Gorilla have already been pointed out: in the whole range
of variety in the human races, no approach is seen to the elonga-
tion of these spines so marked in Gorilla. The only approximation
to the simian condition to be noted, is the lack of bifurcation said
to characterize the lower races. The only other anomalies at all
common in this region are (1) the fusion of two vertebrae, or of
the atlas and occipital bone, and (2) the presence of cervical ribs.
There is not sufficient evidence to associate either of these
characters with definite morphological types, though either feature
may be paralleled among the lower Eutheria and Vertebrata.
The mention of cervical ribs suggests the commonest anomaly
of the thoracic region (which is, on the whole, remarkably free
from variation), viz. : the presence of an abnormal number of rib-
bearing vertebrae1.

1 While not productive of definite evidence to the effect that human types can
be differentiated from one another on the basis of the number of vertebrae they
present, the general question of numerical variations in the various regions
of the vertebral column is so important as to demand a few words of comment
in this place. We must first pass to the lumbar region, at the caudal end of
which occur the most frequent anomalies affecting the numerical formula of
the vertebral column, and particularly consider the evidence drawn from the study
of such variations. This is the more important, as views are still current,
against which most definite statements based on observation have been brought.

280

COMPARATIVE OSTEOLOGY

[SECT. C

Numerical variations in the several regions of the vertebral
column cannot thus be applied to the classification we have here

We refer, in fact, to the theory advanced by Rosenberg as to progressive shortening
of the vertebral column, a process described by that author as normally ontogenetic,
a theory based on evidence shewn by the (alleged) precocious attachment of the
26th vertebra to the pelvic girdle ; this, it was believed, subsequently moves head-
wards, incorporating the 25th vertebra, viz. the normal first sacral : the common
anomaly of the partial or complete incorporation of the 24th vertebra being adduced
as further evidence of the trend of evolution in this part of the skeletal system.
The pelvic girdle is thus represented as capable of shifting along the line of the
vertebral axis, and Rosenberg’s theory explains the alleged shifting in the headward
direction as the outcome of evolutionary changes, which (it is claimed) have been
at work in the Simiidae ; in Hylobates equally with Man, in Gorilla and Chim-
panzee more strongly, and most powerfully in Simia (cf. Cunningham, Journal of
Anatomy and Physiology , xxm. p. 7).

But another view is held, apparently due to Welcker, but of which the chief
living exponent seems to be Professor Dwight of Harvard (cf. Anat. Anzeiger, Band
xix. s. 321), who (in a paper which I have found some trouble in understanding),
explains his view, that the shifting is but a subsidiary cause of the variations ob-
served, which he attributes to irregularity in the number of segments into which
the pre-sacral part of the vertebral column is cut up : the number varying from
twenty-three to twenty-six in a collection of vertebral columns examined by him.
Dwight is thus thrown back on the explanation of irregular segmentation, as deter-
mining the numerical variations in the vertebral column, whether in the lumbar, or
sacral, or other regions ; of this irregularity he does not clearly provide an explana-
tion, nor perhaps can it be provided at all in the present state of our knowledge of
the nature and causation of variations.

Such then are the two views. It would be inappropriate here to set forth the
arguments on one side or the other. Much more to the point however are the
results of Professor Paterson’s exhaustive researches (The Human Sacrum, 1893).
These shew that Rosenberg is probably quite in error in generalizing to the effect
that reduction in the lumbo-sacral region is occurring in Man ; for they shew that
the balance of evidence strongly controverts Rosenberg’s view, and that whether the
explanation is to be found in a shifting of the pelvic girdle (which would be however
tailwards, not headwards as suggested by Rosenberg), or in an appeal to irregular
segmentation (with Dwight), the tendency in Man is to elongation. No less
important is Paterson’s discovery and demonstration that the tendency of nerve-
plexuses is to the incorporation, not of pre-axial but of post-axial nerves, so that
Rosenberg’s view is here controverted. In the third place, it is by no means sure
that in development the second sacral vertebra is apprehended before the first, and
in fact Holl (quoted by Paterson and Dwight op. cit.) gives directly contradictory
evidence. These points have been here specially dealt with, because, even at the
present time, Paterson’s work (of ten years ago), has not received the attention it
deserves : and in view of that work one must, perhaps regretfully, renounce the
belief in what appeared a reasonable forecast of future human development,
possessing the additional advantage of being in accord with the principles of

COMPARATIVE OSTEOLOGY

281

CHAP. XII]

in view, and we must continue our study of that portion of the
skeleton with respect to other descriptive features.

The portions of the vertebral column which have furnished the
greatest amount of material for osteometry are the lumbar and
the sacral regions.

A. The Lumbar vertebrae. Measurements have been made
upon the lumbar portion of the vertebral column. They have been
chiefly undertaken with a view to recording and comparing the
varieties in curvature presented in various forms, and the following
methods have been employed.

1. Measurements made upon the skeleton. It must be clearly
stated at the outset that the results obtainable from measure-
ment of the hard skeletal parts of the lumbar region are
subject to very considerable modification, when reviewed in the
light of the information provided by examination of the recent
spine, in which the intervertebral discs are still present. Though
this circumstance modifies, it does not destroy the value of
researches carried out on the bones alone ; we must also remark
that in many cases of primitive and nearly extinct races, it is
almost impossible that the recent spines will be available,

evolution. From this point of view, Professor Cunningham’s dissent from
Professor Paterson’s conclusions as to the bearing of his observations upon human
evolution needs strengthening. The recent work of Keith ( Journ . Anat. and
Phygiol. xxxvii. p. 18.) shews that from the phylogenetic point of view, and
comparing the Simiidae and Hominidae collectively with the Cercopithecidae,
the evidence favours Rosenberg’s hypothesis : nevertheless the difficulties are
not altogether overcome : thus Simia with twenty- three pre-sacral vertebrae has
too few vertebrae in the sacrum (4-7 on the average when 6 would be expected),
and as regards the Hominidae, Bardeen and Eltung {Anat. Anzeiger, xix. p. 217),
note in negroes a slightly greater tendency to distal displacement of the sacrum
than in white men. Keith admits the tendency, but suggests its greater distinctness
in the negro as evidence that the tendency is apparent, and not real. It does not seem
necessary to adopt this view, for there is no reason why in one such respect the negro
should not be in advance of the white as regards specialisation, which, in this instance,
is in the direction of distal displacement of the sacrum. Finally, as Keith deals
primarily with the comparison of the apes and man, one can hardly expect to find
exhaustive criticism of results of observations directed primarily to human
examples. But it does not yet seem as though the results of Paterson’s work had
been given due weight in these later publications.

282

COMPARATIVE OSTEOLOGY

whereas the several component bones in
paratively easily obtained. The same
consideration applies equally to pre-
historic human skeleton and to fossil-
ised or semi -fossilised remains in
general.

The vertical diameters of the
centra of the lumbar vertebrae may
be measured, and the anterior (me-
dian) vertical diameter compared with
the corresponding posterior vertical
dimension (cf. Fig. 184, A): an index
of height may be constructed expres-
sive of the value of the posterior p interior "Posterior
measurement in terms of the anterior ^edical vertical
height taken as = 100, the index thus larD£^ei diarpeTer
being derived from the formula

[sect, c
sequence are com-

Ceptrurr

Fig. 184. A. represents the
centrum of a lumbar vertebra:
the “ anterior vertical diameter ”
exceeds the “posterior vertical
diameter.” B. is added to indi-
cate the manner in which the sum
of the anterior vertical diameters
may be compared with that of the
posterior vertical diameters.

Index

_ posterior height of centrum x 100
anterior height of centrum

should this index be less than 100,
the vertebral body will be wedge-
shaped, with the base of the wedge

situated anteriorly, and the tendency will be to the production
of a lumbar curvature anteriorly convex. On the contrary, the
index may exceed 100, in which case the tendency is to the
production of a concavity instead of a convexity forwards : or the
intermediate upright condition may obtain.

We may now attempt a brief analysis of the results obtained
from such measurements, comparing in the first instance the
Hominidae with the Simiidae. (Cf. Cunningham, Memoir, II. p. 5.)

A review of the measurements shews that both in the Simiidae
and Hominidae the proportions of the uppermost lumbar vertebra
are such that the posterior central height exceeds the anterior
(the vertebral centrum is therefore wedge-shaped, the base of the
wedge being posterior and the vertebra entering into the concavity
of the thoracic curve). Secondly, when the lowest vertebra is

COMPARATIVE OSTEOLOGY

283

CHAP. XIl]

examined, it possesses, in the Simiidae, proportions similar in
kind but less in degree, to those of the uppermost vertebra ; i.e. the
centrum is wedge-shaped, with the base directed posteriorly, but
base is less wide than in the first lumbar vertebra. In the Horni-
nidae (and also it is interesting to note in the Cercopithecidae1),
the same diminution in the base line of the wedge occurs much
more rapidly, so that the lowest lumbar vertebra has the exactly
opposite character, i.e. it is wedge-shaped with the base anterior.

From these considerations, it follows that in comparing vertebral
columns within the limits of the Hominidae, the retention of the
upper lumbar type in the lower vertebrae of that series is a simian
(but not a cercopithecoid) feature. Within the Hominidae, we
must next consider the influences of age, sex, and race. With
regard to age, we are chiefly dependent upon the data provided
by Ravenel (cited in the sequel), which shew that in the infant at
birth, the anterior and posterior diameters are equal throughout
the lumbar series, a plainly simian feature ; and though it is not
clearly stated, there is in Ravenel’s work an indication that the
distinctive features appear in correlation with the assumption (by
the infant) of the erect attitude.

Measurements made by Cunningham on male and female skele-
tons respectively (Table R, op. cit., v. p. 282 supra), shew plainly
that (1) the posterior height does not exceed the anterior in the
uppermost vertebra by so much in woman as in man, (2) that the
transition occurs higher in the series, from which it is argued that
the characteristic human (as contrasted with the simian) feature is
more pronounced in the female sex.

Turning to the racial influence, it appears from Cunningham’s
table (A) (op. cit.) that certain races (to which a lowly status has
already, from other considerations, been assigned), are in respect
of these proportions distinctly approximated to the Simiidae,

1 The unreliability of inferences drawn from the proportions of the lumbar centra,
as to the attitude, whether erect or prone, of a given animal is hereby emphasized:
this is of special importance when the evidence of fossil bones is under investi-
gation. The number of lumbar vertebrae is well-known to be variable, but it
cannot be said that any particular human race approximates especially to the
Simiidae, in the manifestation of a tendency to reduce the number from five
to three. A similar remark, mutatis mutandis, as regards the number of vertebral
elements concerned, applies to the sacrum.

284

COMPARATIVE OSTEOLOGY

[SECT. C

holding a place intermediate between these and the white race.
The particular races mentioned are as follows : Australian and
Tasmanian aborigines, Andamanese, Bushmen, and Negroes.

A somewhat less elaborate analysis of the character of the
lumbar curve is obtained by constructing the lumbar index in
such a way that the united heights of the centra measured
posteriorly (cf. Fig. 184, B), should the sum of the posterior measure-
ments be less than that of the anterior measurements, the indi-
cation is that of a forward convexity : should the sum of the
posterior measurements be in excess, the convexity forwards is
replaced by a concavity : finally the sum of the posterior may
equal that of the anterior measurements and the column would
then be straight or vertical in this region. The modified lumbar
index is thus derived from the formula

j I sum of posterior measurements x 100
sum of anterior measurements

it is known as the 1 umbo- vertebral index, and numerically its value
fluctuates between about 84'8 and 106 (Turner): in considering
this variation, it is found that the influences of age, sex and race
all take effect. As regards age, the following data are given by
Raven el and Aeby (quoted by Cunningham, “ The Lumbar curve in
Man and Apes.” Cunningham Memoirs, II. p. 73).

In the new-born infant, the height of the vertebrae is the
same before as behind, the index thus being = 100, and the lumbar
column straight.

In the infant at 3 months of age, the anterior diameter begins
to predominate, and this increase becomes more marked as the
infant begins to assume the erect attitude ; the influence of the
extension of the hip-joint is important in this connection (Cleland,
1863) and it is probable that the permanent proportions of the
lumbar centra are not finally assumed till maturity in other respects
has been attained (cf. Balandin, Virchows Archiv, 1873, quoted by
Cunningham). But exact numerical data are scanty.

With regard to sexual variations, Cunningham’s figures for
Europeans, and Dorsey’s1 for American races shew that this factor

1 Dorsey, Bulletin of the Essex Institute, Vol. xxvii., 1895.

CHAP. XII]

COMPARATIVE OSTEOLOGY

285

is distinct, and that the lumbo-vertebral index has on the average
a lower numerical value in females than in males, the indication
being that of more marked anterior convexity, a condition further
removed from that of the Simiidae than that which obtains in
male skeletons.

The racial influence is the same as noted when the several
vertebrae were considered ( v . supra, p. 284).

From the observations of Turner1, the following classifications
of races were drawn up according to the value of the lumbar index
(or lumbo-vertebral index of Cunningham), and with Turner’s data,
those provided by Cunningham may be included here. Three
categories are recognised, and the limits are drawn at 98 and
102, thus :

A. The index is below 98 : Kurto-rachic class : the indication
is of strong anterior convexity. (Cf. Fig. 185.)

Europeans )

Chinese f

(Group iv.2)

Fig. 185. Kurto-rachic type of lumbar conformation in the
vertebral column : there is an anterior lumbar convexity. This
conformation is typical of the (adult) Hominidae.

Fig. 186. Koilo-rachic type of lumbar conformation in the
vertebral column : there is an anterior lumbar concavity. This
conformation is common in the Simiidae and Primates other
than the Hominidae. In the foetal human being and some adult
Hominidae, this type is however found to obtain.

Fig.185.Fig.186.

B. The index is from 98 to 102 (inclusive): Ortho-rachic
class : the convexity is partially masked.

Eskimo. (Group vi.)

Maori. (Group i and Group v.)

To which Dorsey adds : Females of several American aboriginal
races.

C. The index is 102 or upwards : Koilo-rachic class : the

1 Turner, Challenger Report, Part II. “Bones of the Human skeleton,”
pp. 72, 73.

The Roman numerals refer to the morphological divisions of the Hominidae
as described in Chapter xvi. j

286

COMPARATIVE OSTEOLOGY [SECT. C

convexity is still less evident (cf. Fig. 186), or it may be replaced
by a concavity.

Polynesian (Oahu). (Group v.)

Andamanese. (Group iii.)

Negroes. (Group ii.)

Bushmen. (Group vii.)

Australian, with Tasmanian aborigines. (Group i.)

( Simiidae .)

To these Dorsey adds : Males of several American aboriginal
races.

2. The second method of investigation of the characters of
the lumbar region involves the examination of spines in which
vertebrae and intervertebral discs are still in natural apposition,
and which have been sectionized mesially in the sagittal plane.
In such preparations, measurements are made and compared as
what is known by the name of “ the Index of the lumbar curve ”
and this is computed in the following manner.

On the sectionized surface the following measurements are
made. (Cf. Fig. 187.)

The line {AB), joining the
mid-point of the upper surface
of the first lumbar vertebra,
with the mid-point of the lower
surface of the last lumbar ver-
tebra, is measured. On the
section this line is drawn or
marked by a rule or straight-
edge, and the maximum dis-
tance from it to the anterior
surface, measured perpendicu-
larly (CD), is observed. The
proportion of CD to AB is
then calculated, AB, the chord
of the lumbar arc, being con-
sidered = 100. The index of
the lumbar curve

perpendicular x 100
chord

Fig. 187. Diagram representing the di-
mensions compared in the “ index of
the lumbar crnwe ” :

A = mid-point of the upper anterior border
of the centrum of the first lumbar
vertebra.

B - mid-point of the lower anterior border
of the last lumbar centrum.

AB = chord of the lumbar arc.

CD = the longest perpendicular line from
AB to the anterior margin of the
lumbar curve.

COMPARATIVE OSTEOLOGY

287

CHAP. XII]

Evidently the greater this figure, the more prominent will be
the anterior lumbar curvature.

The variations of this character must now be reviewed; as
regards the comparison of the Hominidae with other Primates,
the following values have been obtained : (cf. Cunningham

Memoir II.).

Cynocephalus porcarius.

(d* juv.)

5-6.

(W.L.H.D.).

Orang-utan.

( ¥ juv.)

41.

(Cunningham).

Chimpanzees.

U juv.)

7-1.

( „ )•

„ (av.)

(¥ juv. 3)

93.

( „ )•

Men. (av. of 7)

8-8.

( „ )•

Women. (av. of 8)

9-5.

( )•

Boy. (1)

4T.

(Symington).

These figures shew practical identity between young Simiidae
and adult Hominidae. (The figure for Cynocephalus is not strictly
comparable with the others, for the animal has seven lumbar
vertebrae). The indication afforded by measurements of the
bones alone is thus very materially modified.

With regard to variations within the Hominidae, the influence
of age is seen in the contrast of the index- value (4T) in a boy,
with the average figure for 7 men (8’8) ; the indication being that
in the boy the lumbar curve is incompletely developed. Sexual
differences are shewn by the figures for men (8-8), and women (9-5),
indicating a greater anterior curvature in the latter; but with
regard to race influence, it does not yet appear that data are
available for comparison.

3. As an indication of the racial differences in the curvature
of the spine as a whole, there must be mentioned Cunningham’s
measurements upon living Bush natives (Hottentot-Bush men
as Cunningham calls them) and Irishmen, of the dimensions which
contribute to the formation of the index of “ ensellure1.” This
index was constructed as follows : a tracing is made of the curves
of the spine (by means of strips of lead moulded to the surface
and then removed and traced) : on this a line is drawn from the
most prominent thoracic point to the most prominent sacral point
(the prominence being directed in each case backwards): from

1 Cunningham Memoir n.

288

COMPARATIVE OSTEOLOGY

[SECT. C

Fig

this line a perpendicular is drawn to the point of maximum
curvature in the lumbo-sacral ensellure, as
in Fig. 188 : the larger the index then,
the deeper the curvature and the more
prominent the anterior lumbar convexity.

The Bush natives provided an average index
of 7'2 (for 4 persons) while the average for
two Irishmen was 4'3. This sufficiently
expresses the exaggerated curvature in the
Bushmen, to which appearance their gluteal
development also contributes.

B. The Sacrum : the number of sacral
bones is variable, and on this subject a note
has already been made. The occurrence of
the sacral notch is important : this is a
simian feature due to the attenuation of
the second sacral vertebra as compared with
the first and third : in this way a notch is
formed, opposite to the second vertebra, and
bounded above by the first, and below by
the third vertebra. Such a notch is common

in Simiidae, rare in Europeans, and in

aborigines of Australia, but more frequent in Negroes and
Andamanese (Negritoes)1.

The following are the principal sacral measurements which
have been studied :

(1) The length, measured from the mid-point on the anterior
surface of the promontory, to the mid-point on the anterior surface
of the lower border.

(2) The maximum breadth, measured across the alae.

(3) The depth of the curve, measured on the ventral surface
or on a tracing, being the perpendicular distance from the line
representing the length, to the deepest part of the curve.

(4) The length of the curve, measured on a flexible strip of
metal, or on a tracing (such as may be made with a stereograph).

From the first two measurements a sacral index is derived, and

Breadth of Sacrum x 100

AB joins the
thoracic and sacral pro-
minences : CD is the

perpendicular the length
x of the whole column
being also measured and
taken as = 100 the index
of enselline

CD x 100

the formula is : Index =

Length of Sacrum
1 Paterson, The Human Sacrum; Sc. Tram. Roy. Dublin Soc.

this

CHAP. XIl] COMPARATIVE OSTEOLOGY"

three-fold classification is based, the demarcating numbers being
100 and 106, with a nomenclature as follows :

indices below 100: dolicho-hieric,

indices between 100 and 106 : sub-platyhieric,

indices above 106 : platyhieric.

In the comparison of the Simiidae with the Hominidae, the
relative narrowness of the sacrum in the former, a character
recognisable at a glance, is at once apparent when the sacral
index is considered, for in two Chimpanzees Turner quotes an
average of 77, in two Orang-utans an ave-
rage of 87 (cf. Fig. 189), in a Gorilla 72,
and a Gibbon 89, as against an average
(male) human index of 112'4. The Simiidae
are thus dolicho-hieric. The influence of
age is discussed by Professor Thomson
(Journal of Anatomy and Physiology , Yol.
xxxiii., p. 372 — 3)1. As average values
for four sacra of each sex in the foetus, he
records for males 104, females 99'7, both
practically within Turner’s platyhieric class,
or Paterson’s sub-platyhieric class. Thomson
insists rather too strongly upon the pre-
cocious attainment of the permanent adult
proportions by the sacrum, and it seems as though the figures
really suggest a slightly inferior status to that obtaining in
the adult.

The influence of sex is shewn by Turner, who has compiled
indices from his own measurements, combined with those of
several other workers, which yield the following figures for Euro-
peans: male 1124, female 1 1 6*8 ; the female sacrum is thus
evidently the broader. (In the foetal pelves the reverse condition
obtains, and of this no explanation is forthcoming.)

Racial influences in determining the form of the sacrum cannot
be overlooked. The classification based upon the numerical value
of the sacral index results in the following divisions :

Fig. 189. Pelvis of an
Orang-utan (Hose do-
nation ii. Mas. Anat.
Cant.) ; to shew the
flattened iliac bones, the
straight narrow sacrum,
and transversely con-
tracted pelvic brim.

D. M.

1 v. supra, Chapter vn., pp. 175, 17G.

290

COMPARATIVE OSTEOLOGY

[SECT. C

Nomenclature
I. Dolicho-hieric :
Index below 100.

II. Sub-platy-hieric :
Index between 100 & 106.

Human race

The Roman numerals
refer to the morphological
divisions of the Homini-
dae as set forth in

Chapter xvi.

Bush race (with Hottentots).

Group VII.

Bantu Negro.
Simiidae.

Group II.

Andamanese.

Group III.

Australian (with Tasmanian).

Group I.

Negro.

Group II.

Chinese.

Group IV.

Also Ainu (contrary to Turner’s surmise) and Japanese (of. Koganei, Das
Bee ken der A ino und Japaner , p. 34) men.

III. Platy-hieric :

Index over 106.

N. & S. American.

with Peruvian.

Group IV.

Eskimo.

Group VII.

European and Lapp.

Group IV.

Melanesian & Polynesian.

Groups I. & V.

Hindoo.

Group IV.

Guanche.

Group IV.

Malay.

Group IV.

Ancient Egyptian.
Ainu women.
Japanese women.

Group IV.

But the length-measurement of the sacrum is open to the
objection that it does not express the degree of curvature of the
bone, a curvature that is very marked in some cases. A numerical
estimate of the degree of curvature may be obtained by comparing
the length of the sacrum measured in accordance with the direc-
tions given on a preceding page, with the corresponding length
measured along the ventral curved surface of the bone by means of
a flexible measure. Though this method was suggested by Professor
Cunningham at Glasgow in 1900, no data seem to have yet been
published in illustration of the method. Another method is to
measure the maximum depth of the curve by means of a per-
pendicular drawn from the line representing the direct length,
to the deepest part of the curve : the average value of this line
is 25T in the white, and 13*2 in the black race (Paterson).

CHAP. XII] COMPARATIVE OSTEOLOGY 291

The researches of Paterson1 shew that the curve is deepest
opposite the third sacral vertebra, and the curvature is greater
below than above this point. It is not as a rule equal and uniform,
but flattened above, and more distinctly curved below the third
sacral vertebra (Paterson, op. cit.). In the Simiidae the curve
is distinctly less than in the Hominidae, but the curve is similar
in character to that obtaining in Man, i.e. the curve is more
pronounced in the lower part of the bone. The several genera
vary: the Gorilla and Orang are in this respect most closely allied
to Man, for the greatest depth is represented by average figures
of 104 mm. and 10‘6 mm. respectively: in the Chimpanzee, the
curvature is less, being represented by an average of 6‘6 mm., and
in Hylobates this is reduced to 3T mm., so that hardly any
curvature can be said to exist. In the white Hominidae the
average figure is 25T. Within the Hominidae, age determines
the degree of curvature which, though present from a very early
period (e.g. in a foetus 46 mm. in length, and consequently about
3 months old) is not fully developed till the infant has attained
the erect attitude : the difference between the Simiidae and the
Hominidae depends on the same consideration.

As regards sex, the general conclusions quoted above from
Paterson’s memoir, are said by that author to apply equally to
both sexes, though he adds that the female sacrum is more often
curved more deeply in its upper part than the male sacrum. At
the same time the actual amount of curvature is greater in the
male sacrum irrespective of the absolute size of the sacrum.

C. The Pelvis. Apart from the proportions of length and
breadth which will be considered under the heading of pelvimetry,
the chief characteristics of the human pelvis are its compactness,
the pronounced curvature of the ilia with the consequent produc-
tion of iliac fossae, the development of the anterior inferior iliac
spines, and the prominence of the ischial spines; on the ilio-
pectineal line, the processes so frequent in the corresponding
situation in the pelvis of Sitnia, are rare. Within the Hominidae,
the sexual differences are perhaps the most striking, and while
these and other differences such as those due to race, will be

1 The Human Sacrum. Sc. Trans. Roy. Dublin Society.

19—2

292

COMPARATIVE OSTEOLOGY

[SECT. C

further dealt with in connection with pelvimetry, the following
remarks may here be made as bearing upon some descriptive
points. The most recent and accurate contributions to this subject
are those of Professor A. Thomson1, and some of the conclusions
arrived at by this author will now be given. We may notice then
that the following sexual differences in pelvic form are distin-
guishable in human foetuses from the fourth month of pregnancy
onwards.

(1) The parietes of the pelvis converge more rapidly from
above downwards in the male, the pelvis being therefore more
funnel-shaped in that sex.

(2) The ischia are more nearly approximate in the male,
thereby narrowing the pelvic outlet.

(3) The iliac crests are less in-curved anteriorly in the male
pelvis, contrary to the usual descriptions.

(4) The iliac crests reach a higher level and are more pro-
nounced in the male pelvis.

(5) The great sacro-sciatic notch is narrower in the male
pelvis.

((j) The sub-pubic angle is smaller in the male pelvis.

Of these characters, No. 3 is one in respect of which the
Simiidae differ markedly from the Hominidae, and within the
latter family, certain races (notably Group VII., v. infra) are
distinguished from others on similar grounds. The last character,
viz. No. (j, may be estimated by measurement and this brings
us to the second part of the subject, viz. pelvimetry.

In comparing the human pelvis with those of the lower
Primates, for instance one of the Cercopithecidae, or with most
examples of the other Eutheria, a striking difference consists in
the proportions of length and breadth of the pelvis as a whole:
in the lowlier forms, the breadth is relatively smaller, and there
is comparative elongation in a direction measured from the most
anterior part of the iliac crest to the most posterior portion of
the ischial tuberosity: in the human pelvis the breadth has
increased with concurrent diminution in length. The Simiidae
in these respects, are intermediate between the Cercopithecidae
and the Hominidae. (Cf. Fig. 190; A, B, C.)

1 Journal of Aunt, and Physiol., Vol. xxxm., p. 59.

293

CHAP. XII]

COMPARATIVE OSTEOLOGY

Fig. 190. The pelves of (A) Hylobates, (B) Gorilla, and ( C ) Man. The frontal
and lateral aspects are shewn. The form of the brim of the true pelvis is indicated
diagrammatically in A and B (to the left of these figures). (After Huxley.)

294 COMPARATIVE OSTEOLOGY [SECT. C

When the several constituents of the pelvic girdle are con-
sidered, and when the ossa innominata of the Hominidae and
Cercopithecidae are compared, similar differences obtain to those
just described ; for in the Cercopithecidae, the os innominatum
is narrow in the direction from its pre-axial to its post-axial
border, whereas between these two margins the human os in-
nominatum is broad : and again, measured from the iliac crest
to the ischial tuber, the os innominatum of the Cercopithecidae
is elongated in comparison with the stout shortened human bone.
Some of the differences of detail which distinguish the os in-
nominatum of Gorilla from the corresponding human bone are
represented in Fig. 191.

CHAP. XIl]

COMPARATIVE OSTEOLOGY

295

These proportions have been expressed in the form of indices,
and thus there are indices (1) for the whole pelvis, the pelvic
index proper, not to be confused with the pelvic brim-index
presently to be described, and (2) the index of the os innomi-
natum.

The proportions of the pelvic brim are seen to differ markedly
in the Cercopithecidae and most Eutheria, from those which obtain
in the human pelvis. When the diameters, measured in the
sagittal and transverse directions respectively, are compared, the
former (the sagittal) will be found characteristically greater than
the latter (transverse) in the lower Eutheria and Primates : this
excess is reduced in the higher Primates, but in Man the reverse
condition obtains. Comparing the two dimensions, the transverse
diameter being taken as = 100, an index of the pelvic brim (often
called the pelvic index, though quite distinct from the index of
the pelvis as a whole), is obtained.

The general results of investigations upon these three indices
may now be considered.

(I.) The proportions of the pelvis as a whole. The proportions of
antero-posterior length (in Man, this dimension is called “height”),
and transverse diameter (breadth) are compared by means of the
pelvic index. Taking the latter diameter as =100, the value of
the former (antero-posterior length) has been calculated for various
animals, and Topinard1 gives the following list, here slightly
modified in accordance with the definition of the index :

Metatheria : Macropodidae
Eutheria : Edentata . . .

Rodentia ...

Carnivora

Ungulata artiodactyla
Primates. Lemuroidea

Cebidae ' ...
Cercopithecidae
Simiidae ; Hylobates

Index

139

138

133
132
123
144
135

134
121

1 (a) Revue d' Anthropologic, 1874-5. (h) L'Homme dam la Nature.

COMPARATIVE OSTEOLOGY

[SECT, c

Primates. Simiidae ; Av. of the three

larger forms . . .

„ Chimpanzee

„ Simia

„ Gorilla

(! Ungulata Perissodactyla

82)

To these may be appended the following figures from various
sources1 :

Hominidae: Average for white races ... ... 73

(Turner quotes variations from
74—79.)

Bush native (c/1 2) (1) ... ... ... 91

Negro (4 J") ... ... ... 80

„ (2?) 73

European (J) ... ... ... 79a

„ (?) 74a

Eskimo (1 </) ... ... ... ... 77

_ (1 ?) 77

Oceanic negro ... ... ... 77

Australian aboriginal (6 </) ... ... 76-8

(1 ? ) 76

Andamanese (2 </) ... ... ... 76-5

(3?) 76

Aino (cf ) 7 6-3 3

„ (?) '72-9*

Japanese (</) ... ... ... ... 74'63

„ (?) 72-23

Polynesian (5 </) ... ... ... 72‘3

European foetus (4 </) ... ... 85 -6

„ (4?) 82-4

From the foregoing list, it appears that the lower Eutherian
mammals possess pelves of proportions very different from those

1 Turner, Challenger Report, Part n. Rones of the Skeleton.

2 Verneau, quoted by Turner, op. cit.

3 Koganei, Das Becleen dev Aino and der Japaner.

COMPARATIVE OSTEOLOGY

297

CHAP. XIl]

of the Hominidae, and that even the Order Primates alone
provides a wide range of variety in this respect. Within the
Order Primates, the proportions are seen to change progressively,
in the sense of increase in pelvic breadth, from the Lemurs
up to Man, the Simiidae in this, as in so many respects, being
associated with the Hominidae rather than with the lower Primate
forms. When comparisons are confined to the Hominidae, the
influence of age is revealed by inspection of the index in the foetus
and adult, and it is to be concluded, that judged by this test the
foetus bears marked tokens of simian affinity.

When the sexes are compared, the female is seen to possess
the human characteristic proportions in a more intensified degree
than does the male, the latter being in this respect indeed com-
paratively simian.

When we turn to the data provided by various races, we find
that certain of these are to be regarded as less removed from the
Simiidae than are the white races. From the examination of the
data available, and of the races investigated, the Bush race of
South Africa seems to be particularly simian, and to nearly
approach the Orang-utan in pelvic proportions.

With these remarks we may turn from the consideration of
this index to the study of the proportions of the innominate bone.

From the foregoing remarks, it will be foreseen that the pro-
portions of antero-posterior length (height, in the human skeleton)
and dorsi-ventral diameter (breadth, in human anatomy) of the
os innominatum, provide what is to a considerable extent a re-
capitulation of the foregoing results, so largely is the pelvic form
dependent on the proportions of this constituent.

(II.) If an index of the innominate bone be constructed so
as to compare its height, measured as in computing the preceding
index, with the iliac breadth, measured from the anterior to the
posterior superior iliac spine, and if it be arranged so that the index
_ iliac breadth x 100
innominate height

. we shall find the following data :

Chimpanzee (1 juv. ?sex)
Gorilla (1 male ad.)
Human foetus (4 male)

g l (W.L.H.D. private coll.).
07 '6 (Thomson, op. cit.).

298

COMPARATIVE OSTEOLOGY

[SECT. C

Human foetus (4 female)

69-7

(Thomson, op. cit.)

White race (adult males)

74-5

(Vemeau, Le bassin,

Paris 1875.)

„ „ ( „ females) ...

79T

» »

Australian aborigines (0 males)

79-6

(Turner, Chall. R. Pt. n.)

„ „ (1 female)

88-0

» » ?)

Negroes „ (3 males)

80-7

>> » »

„ „ (2 females)

98-5

>> » )>

Bush native ( 1 male) ...

82-0

» )) >>

Polynesian Islanders (5 males)

88-0

» )} ))

Eskimo race (1 male) ...

89-0

)> )) yt

„ „ (1 female)

87 0

))

)> >> »

Andamanese (2 males)

89-0

))

>> )) >)

„ (2 females)

9T0

>> )> )>

In this respect the Simiidae and Hominidae are clearly con-
trasted, the latter possessing the shorter broader ossa innominata;
within the limits of the Hominidae, the indication is that the human
character is acquired in the foetal stages, but is not then so pro-
nounced as later, so that the foetus presents features intermediate
between those of apes and adult human beings. In the comparison
of the sexes, it will be noted that differences obtain even in foetal
life, and that the female pelvis is characterized by the more pro-
nounced development of the typical human proportions than is the
male pelvis, the latter being thus inferior in point of evolution.

When we study the various data for the several human races,
we find a most curious reversal of the order obtaining in regard
to the breadth-height index just described, and the difference can
on ly be explained by an appeal to the characters of the sacrum :
the excess of sacral width in the white races being sufficient to
cause the figure representative of their breadth-height pelvic
index to exceed that for the other and darker races.

(III.) We come in the next place to the index of the pelvic
brim, which is derived from the expression:

. . antero-posterior diameter of the pelvic brim x 100

index = 1 — i — — — ,

transverse diameter

The latter dimension is measured from the posterior margin of
the symphysis pubis to the promontory of the sacrum.

CHAP. XIl]

COMPARATIVE OSTEOLOGY

299

The following data are provided by Turner1 :
In an Ox the index is 110-0

Camel

))

110-8

Chimpanzees (2)2

133-0

Orang-utan (2)

))

126-0

Gorilla (1)

144-0

Hylobates (1)

151-0

to which may be added

Hylobates (</ 1)

^8l W.L.H.D. Mus. Anat. Cant.

<? i)

128-5 f

Coming to the value

of the index in adult European male

pelves, we find that it

rely exceeds 90 (Turner, op. cit. p. 35).

The comparison of Hominidae with the other Eutheria men-
tioned, shews sufficiently plainly the diminution in the pro-
portionate value of the conjugate diameter, which, as may be
seen from the index-formula, is the variable quantity in the series.

Within the Hominidae, we have now, as in preceding cases,
to consider the factor of age. Formerly, the foetal pelvis was
believed to reproduce to some extent the lower Eutherian form,
but Professor Thomson in his able paper already quoted, shews
that this opinion must be revised, for the average index in four
male foetuses of ages ranging from 4 to 7 months is only 86, and
in four female foetuses of corresponding age, the figure is 83.

The latter statement reveals the influence of sex, which is
thus seen to be active even at an early stage in development : it
is still further emphasized in adults : and the difference will be
observed to be one which relegates the male pelvis to a position
nearer the Sirniidae than the female human pelvis : a result which
accords with the indications given by the two preceding indices of
the pelvis.

The racial influence is seen most plainly in male pelves, for in
no race does the average index for female pelves approach nearly
to the figure for male pelves. Upon considerations of this index,
Turner (op. cit.) has based the following classification : in all cases
male pelves are dealt with.

1 Challenger Reports, Part ii. Bonce of the Human Skeleton.

* The figures in brackets indicate the number of individuals observed.

300

COMPARATIVE OSTEOLOGY [SECT. C

A. Pelves in which the brim index is above 95— Dolicho-
pellic :

Examples : Australians (i)1.

Bush natives (vil).

Bantu negroes (u).

Andamanese (ill),
and possibly Polynesians (v).

B. Pelves in which the index is 95 — 90 inclusive — Mesati-
pellic.

Negroes (n).

Tasmanians (i).

New Caledonians (i).

C. Pelves in which the index is below 90 — Platypellic.

White races (Eurasiatic including Aino).

Yellow races (including Japanese)2 (iv).
and probably Eskimo (vi).

In the foregoing classification, the dark races (Kaffirs, Bush
and Australian), resume their position of closer approximation
(than the white races), to the Simiidae, and from this and the other
pelvic indices, the value of this part of the skeleton as a means of
distinguishing morphological human types will be clearly under-
stood.

The enquiries as to how far the form of the brim of the true
pelvis affects the head of the infant at parturition, and how far
such modification may in turn be related to heredity of head form
are natural subjects for discussion in this connection. The re-
searches of GonneC shew that as regards the modern Swiss (Basel),
the general result of parturition, even in a brachycephalic popula-
tion, is to modify the head form in the direction of dolicho- cephalic
proportions4. Should the mother be brachycephalic, the infant
will be also brachycephalic in 25 °/0 of cases only: in only 18 °/0 of
cases is there concordance with the paternal form of head. But if
the presentation is of the breach variety, and in Caesarian sections,

1 Roman numerals denote human types as distinguished in chapter xvi.

2 Koganei : op. cit. p. 19. Cf. p. 296 supra.

3 “Vererbuug der Forme des Schiidels, ” Zeitschri/t fiir Geburtshilfe and
Gynaclcologie, 1895, Band xxxm.

4 Cf. Chapter vn., p. 162.

CHAP. XIl]

COMPARATIVE OSTEOLOGY

301

the concordance is more frequent. But in any case, these re-
searches shew no close correlation between parent and child. Nor
is it very different as regards the size of the head, as tested by the
measure of its circumference : when both parents have large heads,
the child’s head is in accord : but when only one parent has a large
head, the infant’s head is just as likely to be small as large and
this is independent of whieh parent has the large and which has
the small head, i.e. there is no pre-potency of either parent. The
infant’s head tends to become more brachycephalic in the first
month of post-natal life, suggesting that the general result of
parturition as mentioned above, is to impress dolicho-cephalic
properties temporarily on the infant’s head.

D. The Thorax. The human thorax in section presents
a reniform appearance, the hilum corresponding to the depression
along the vertebral column : the transverse diameter exceeding
the antero-posterior diameter in a marked degree : similar propor-
tions thus obtain to those observed in the pelvic brim (and it may
be added, in the centra of the lumbar vertebrae). In the Simiidae
the antero-posterior diameter is relatively increased, and in the
pronograde Primates and lower Eutherian mammals, the section is
almost elliptical, with the antero-posterior axis predominant, the
exact converse in fact, of the human thorax. A thoracic index has
been devised to illustrate the difference numerically. The antero-
posterior diameter being taken as equal to 100, the index follows
from the formula :

Weisgerber (quoted by Topinard, El. yen. cl’ A. p. 1051) gives
the following average values, here modified in accordance with the
formula quoted above :

index —

antero-posterior diameter x 100

transverse diameter

1 6 Carnivora
04 Cercopithecidae

131-6
116-2
102-0
89*3
85-4 1

22 Cebidae
27 Simiidae
99 Men ...

1 Hovelacque and Herve give 78 as the average for ten adult human examples.

302

COMPARATIVE OSTEOLOGY

[SECT. C

A foetal thorax provides an index of 96'5 (W.L.H.D.).

W hile the distinctive position of the Hominidae is thus marked,
and the intermediate or pithecoid condition is evident in the human
foetus, the influences of sex and race are not yet clearly known:
though Weisgerber’s figures suggest that the female skeleton is
more nearly simian than the male in this respect.

In the study of the skeleton we have thus noted the vertebral
column (the lumbar and sacral parts being particular objects of
attention), the pelvis, and the thorax, with special reference to the
proportions of the latter. It may not be out of place to add here
a note pointing out that the peculiar characters of the human
skeleton as regards these features, are all concordant and dependent
upon the one factor of the erect attitude : in relation with this
are developed anterior lumbar convexity in a high degree, sacral
width and curvature in a high degree, and increase in the trans-
verse diameters of the pelvic brim and thorax, and these characters
are largely due to the action of the body weight as carried in that
particular attitude.

Pathology sometimes demonstrates the correctness of this
statement and provides the experiment of softening the tissues
so as to allow the weight additional opportunities for manifesting
its effects. Thus in Rickets (cf. Fig. 193), the increased effect of
weight is shewn by the exaggerated lumbar curve, the exaggerated
sacral curvature, and the increased transverse diameter of the
pelvic brim. Again in cases where disease has induced the bowed
and bent attitude of spinal kyphosis (cf. Fig. 194), the lumbar
curve diminishes, approximating to that of the simian form, the
sacral curve is all but obliterated, and the antero-posterior pelvic
diameter asserts itself, gaining in size upon the transverse
diameter, which it may even surpass. Reduction in the transverse
diameter of the brim is still more marked in the pelvis in which
bilateral synostosis of the sacro-iliac articulations has occurred
(Fig. 195, with which compare Fig. 192).

In spinal curvature consequent on caries, the lumbar curve
may be increased and the thoracic proportions will be modified
in the direction of further antero-posterior diminution in diameter.
The effect of gravity in producing these results has been very
cleverly demonstrated by Professor Dwight, who by adjusting

COMPARATIVE OSTEOLOGY

303

CHAP. Xllj

a circle of flexible steel ribbon (clock-spring) so that its plane is
either vertical (corresponding to the horizontal vertebral column of

Fig. 194.

Fig. 193.

Fig. 195.

Figs. 192 — 195. The female pelvis. Fig. 192. The normal form. Fig. 193. The
pelvis in Rickets, with the brim widened laterally and compressed antero-posterially.
Fig. 194. The kyphotic pelvis, in which the transverse diameter is narrowed, and
the antero-posterior diameter increased. Fig. 195. The pelvis with bilateral syn-
ostosis of the sacro-iliac synchondroses. The transverse diameter is much diminished,
and the antero-posterior diameter correspondingly increased. This type (pelvis of
Robert) and the preceding (Fig. 194) should be compared with the simian pelves
shewn in Figs. 189 and 190 (A and B).

pronograde animals), or horizontal (as in the thorax of orthograde
animals), has shewn the differences in contour which the circle
assumes, and has pointed out that these correspond precisely to
those actually observable in the thoraces of pronograde and ortho-
grade mammalia respectively.

E. The anterior Limb-girdle. The modifications of the
clavicle according to age, sex, and race are not clearly known
and will accordingly be passed over in this place.

The scapula of Man differs from the generalized Eutherian
scapula in the great size of the acromion process, and in its
proportions, the scapular breadth, measured from the glenoid
margin to the vertebral border, being relatively small in Man.
Figs. 196 and 197 represent the differences which obtain in
these respects between the scapulae of a Rodent (rabbit) and Man

304

COMPARATIVE OSTEOLOGY

[SECT. C

(Fig. 197). Intermediate stages are met with in the Simiidae, but
strictly comparable measurements are very
difficult to make, especially in the scapulae
of the Orang-utan and Chimpanzee ; indeed

in many cases the reduction in breadth seems
to the eye to have advanced to a further
stage in these forms than in Man. The
scapula of the Gorilla resembles that of
Man more closely than those of the other
forms mentioned, the acromion process
being larger and consequently more human.
Another interesting anatomical feature is

greater extent of the supraspinous fossa in the apes. The quantita-
tive estimation of some of these characters may now be considered.

A. The proportions of scapular breadth and length have been
expressed by a scapular index

_ the breadth from glenoid margin to vertebral border x 100

(the denominator being considered = 100), and it must be re-
peated that the instructions for measurement, though well adapted
to the human scapula, prove difficult of application to other
scapulae, such as those of the Orang-utan (Simia). The following
figures are given for this index by Broca (quoted by Hovelacque
et Herve : Precis d’A nthropolugie , p. 103).

Carnivora 136 — 200

Cercopithecidae 110 — 144

[Hylobates 1 17 5 W. L. H. D. Mus. Anat. Cant.]

the osseous process which is developed
when the M. teres major is unusually
massive: and another character that has
been investigated is the angle included
by the line of the scapular spine and

that of the vertebral border. This angle ofu Rai
(cf. Fig. 198) is more oblique in the Fit?.
Simiidae than in Man, and is related to the scapula

Fig. 196. Right scapula

of a Rabbit.

Fig. 197. Right human

the length superior to inferior angle

Hylobates

Simia

CHAP. XIl]

COMPARATIVE OSTEOLOGY

305

Livon, Flower and Garson
give similar figures.

(I1)

(27 2)

(100)

(32)

(10)

(462)

(26)

(8)

Gorilla 70 '38

Anthropopithecus 68'52

To which may be added

Central African Pygmy 87'9
Andamanese • 7 0’2

Negroes 69*7

Polynesians 6 6 -6

Bush 66'2

Europeans 65-3

Australians 64’9

Eskimo 61

From this table it appears that the Simiidae and Hominidae
overlap to a considerable extent: while the former merge into
the Cercopithecidae ; nevertheless a considerable gap separates
the three larger Simiidae from Hylobates, whose affinities are
clearly with the Cercopithecidae in respect of this index. Of the
Hominidae, while the variations are very great, the foetus (with
a scapular index of 80 at the mid-term of pregnancy) is more
simian than the adult man : sexual differences and lateral differ-
ences (i.e. between right and left scapulae) are obscure, and as
regards racial influences the pygmy and black races evidently
provide the most simian type.

B. The following figures are
given by Turner {op. cit., p. 87)
for the scapulo-spinal angle. (Cf. Fig.

198.)

Chimpanzee (av. of 4) 50o-5

Orang-utan (av. of 2) 660,5

Aborigines of Australia (11) 780,2

(67° to 86°)

Europeans (25) 82=-5

(73° to 91°)

So far then as the data go, it
appears that the angle is greater in
the Hominidae than in the Simiidae,

1 Shrubsall, in Johnston’s Uganda, Vol. ii.

2 From Turner, Challenger Report, Part ii.
number of observations in each case.

D. M.

scapula, shewing the lines by
which the scapulo-spinal augle
is included.

The figures in brackets give the
20

COMPARATIVE OSTEOLOGY

306

[SECT. C

and that Australian aborigines are more simian in this respect
than are Europeans.

F. The Sternum. The chief feature of importance in the
sternum, considered in relation to the comparative morphology
of the Hominidae, is the level at which the sutural line
between pre- and meso-sternum persists (cf. Chapter IX.). In
the white races this level is commonly that of the second
costal cartilage, but in aborigines of Australia the level of the
third costal cartilage often marks the line of the persistent suture.
Turner {op. cit., cf. p. 305 supra), mentions a similar case in the
sternum of an Andamanese Islander, and Keith has recorded the
occurrence and noted its relative frequency in the Simiidae,
pointing out its special frequencj' in Hylobates1. Thane2 notes
that the female sternum is relatively shorter (9'2 °/0 of stature)
than the male (9‘5 °/o of stature), and that the proportions of
pre- and meso-sternum differ in the two sexes. The phenomenon
of perforation of the meso-sternum seems to have a general
morphological significance only.

1 Keith, Journ. Anat. and Physiol., Vol. xxx. p. 27(5 (189(5).

2 Quain’s Anatomy, Vol. n. Part I., Osteology. References to several papers
are quoted.

CHAPTER XIII.

COMPARATIVE OSTEOLOGY (CONTINUED).

Having concluded the sketch of the morphological variations
of the sternum, we have surveyed all parts of the skeleton,
with the exception of the limbs, which accordingly now demand
attention. A few descriptive remarks on each of the principal
limb-bones will be followed by an account of the most instructive
characters of the limbs hitherto established from researches in
comparative racial morphology, viz. the differences observed in
the proportional lengths of the two limbs and of their several
segments. The number of characters considered is here strictly
limited, as exhaustive accounts are accessible in various text-books
on Human Anatomy. It will be convenient to consider first the
upper limb, commencing with the humerus.

The Humerus. With regard to the general morphological
characters of the humerus, and of such variations as may be as-
cribed to the factors so often enumerated in the preceding chapter,
viz. position in the Natural Order Primates, Age, Sex, and Race,
the evidence at hand is still comparatively scanty in amount.

A. Dealing first with the shaft, one may notice that in the
Simiidae, more especially in Simia and Gorilla, the humeral
diaphysis is very commonly more curved than the shaft of the
human bone, and it is further interesting to notice that almost
the exact converse statement applies to the femoral diaphysis
in Simiidae and Hominidae. Thus the humeral shaft is curved
(the concavity being directed anteriorly), the femoral shaft straight

20—2

308

COMPARATIVE OSTEOLOGY

[SECT. C

in Simiidae, while the humeral shaft is straight, the femoral shaft
curved (with the convexity directed forwards) in the Hominidae1.

Hence a curved humeral diaphysis is to be regarded as a
simian character. The same description will apply to humeri in
which the external supracondylar line is so prominent as to form
a flange-like projection from the shaft (this appearance is par-
ticularly common in the humeri of Gorillas).

B. The torsion of the humeral shaft has attracted a good
deal of attention, for in its degree this character distinguishes
the human humerus from those of quadrupedal mammals2. In
the latter, the long axes of the upper and lower articular ends
of the humerus are inclined at right angles approximately; Broca’s
measurements assigning a value of 940,9 to the average angle
among Carnivora. The same observer’s figures for the average
value of the angle in modern inhabitants of France is 164°; the
degree of torsion here nearly amounting to two right angles. The
range of human variation is overlapped by that of the Simiidae,
whose close association with the Hominidae is thus once more
indicated. And through the Primate series the numerical value
of the angle gradually falls, till in the lowest forms it closely
approximates to the average figure quoted for the angle in
Carnivora. The following data (from Broca’s research) are in-
structive. Average value of the angle of torsion :

Carni vora

94°-9

Lowest Primates

95°

Simiidae ; Hylobates

112°

„ Simia

120°-25

(Chimpanzee) A. niger

128°

„ A. gorilla

141°

Hominidae; Modern French

164°

1 The comparison of the human humerus and femur with the corresponding
bones of a Gibbon (Hylobates) will be found particularly instructive on this point.

2 It may be remarked that no consensus of opinion appears to exist as to the
exact nature of this torsion, nor as to which parts are affected and which are
unaffected by the process, i.e. whether the shaft is unaffected and the torsion is
produced only at the articular ends, or whether all parts are involved. No spiral
fibres are seen in the structure of the bone, and as for the spiral course of the
musculo-spiral nerve, it is such that it represents torsion in exactly the opposite
direction to that which is described as having occurred. Besides, the other
nerves shew no signs of a spiral course.

COMPARATIVE OSTEOLOGY

309

CHAP. XIII]

Within the Hominidae, the factors of age, sex, and race must
be taken into account. As regards the former, Gegenbaur has
established the occurrence of ontogenetic torsion amounting in all
to about 35° in the course of development. Macalister ( Text-Book
of Human Anatomy ) gives 30° as the value of the amount of
ontogenetic torsion. No sexual difference has been noted1.

Coming to the racial variations in torsion, we must again
note the researches of Broca, which provide the following average
figures.

Average value of the angle of torsion :

Aborigines of Australia

134°-5

Negroes

144°

Polynesians

144°

White race (average)

161°

C. The frequency of the occurrence of perforation of the
olecranon fossa has been studied by various observers ; normal
in certain Eutherian orders, it is a variable character in others :
in the Simiidae there is little doubt that it is more frequent than
in the Hominidae : within the limits of the latter family its
frequency seems to be associated with other differences of racial
significance, but the indications still lack definition. With a
per-centage of 4 to 5 in western Europeans may be contrasted
the per-centages of 21-7 in African negroes, 34’3 in Polynesians,
and 36'2 in the “ Altaic ” and American aboriginal races (Herve
and Hovelacque, Precis, p. 291). Moreover, the character seems
to have been much more frequent in the prehistoric period, for the
per-centage figure is 25'6 in the prehistoric Guanches of the
Canary Islands; and in the pre-dynastic inhabitants of Egypt,
Professor Macalister records the extraordinary figure of 60°/o of
perforated olecranon fossae. S. Hilaire found perforation of the
fossa in the skeleton of the Bush-woman known as the “ Hottentot
Venus,” dissected by Cuvier early in the 19th centuiy.

D. Obliquity of the forearm in extension.

A well-marked sexual difference is to be found in the relation
of the long axis of the trochlear articular surface at the lower end
of the humerus to the axis of the shaft. Macalister ( Human
Anatomy, p. 144) states that “ the axis of the trochlea is oblique,
1 Gegenbaur: Jenaische Zeitsch. Bd. iv. 1868.

310

COMPARATIVE OSTEOLOGY

[SECT. C

cutting that of the humerus at an angle salient outwards of 105°
in the male, 108 in the female. Careful observation shews
(Fig. 199) that in the extended position, the axis of the forearm
is consequently not identical with that of the arm, but inclined

Fig. 199. Diagrams of the bones of the arm and forearm in (A) Man, and
(B) Woman : to shew the greater obliquity of the forearm in the latter sex.

out and downwards, the outward inclination being greater in the
female. This character has also been investigated by Dr Potter1,
who shews that the sexual difference in obliquity amounts on the
average to approximately 6°, the figures being as follows : for
males (95*) the deviation from the axis of the arm is 60-8, and
for females (90 2 3), the corresponding angle is 12°'65. Moreover
Dr Potter describes the rectification that occurs in flexion, whereby
in the position of extreme flexion the axes of arm and forearm
coincide (in both sexes)a. It will be noticed that the statements
of Macalister and Potter are not quite concordant ; for the angle

1 Journ. of Anat. and Phys., Vol. xxix. p. 480.

2 The figures in brackets denote the number of observations.

3 In the lower extremity, a corresponding obliquity of the axis of the leg with
regard to that of the thigh constitutes the condition of “genu valgum” (knock-
knee). In this condition the deformity presented in extension of the knee-joint
disappears when the leg is flexed upon the thigh (Potter, op. cit. p. 491).

CHAP. XIIl]

COMPARATIVE OSTEOLOGY

311

of obliquity described by Potter ought to tally with the difference
between the angle quoted by Macalister and a right angle (i.e. the
difference of 105° and 90° = 15° for males, of 108° and 90° = 18°
for females: Potter’s results are as above, 6°'8 for males, 12°'65 for
females). As Macalister’s results are not accompanied by a state-
ment as to the number of examples whence the generalisation is
drawn, no final selection of the conflicting statements is at present
possible1.

Bones of the Forearm. Morphological variations associated
with racial influences are very rare in the bones of the forearm.
The occasional elongation of the styloid process of the ulna so as
to produce an articulation between this process and the cuneiform
bone of the carpus, suggests the fusion with the styloid process of
a carpal ossicle belonging to the series described by Vesalius (os
Vesalii) and others as sporadically occurring in this situation.
(Cf. Forsyth- Major. “The Osteology of the Lagomorpha.” Linnaean
Trans. Vol. VII. Ser. 2, pp. 464 et seq.)

The interosseous space of the forearm is both absolutely and
relatively larger in the larger Simiidae than in the Hominidae, the
radius and ulna being distinctly bowed in the apes. Any approach
to this condition would constitute a simian peculiarity should it
occur in a human being, but the appearance is, so far as I know,
a rare one: it is to be expected in the skeletons of aborigines of
Tasmania, Australia, or the Andaman Islands, or in the Bush race
of South Africa, and is present in the Neanderthal skeleton2.

The Femur. A great number of anomalies of formation and
development have been described in the femur. As in previous
instances, only a very small selection will be noticed in this
connection. (A) The curvature of the shaft of the femur has
already been incidentally mentioned, and ( B ) the variations in the
angle between the axes of the femoral neck and shaft have been
briefly described in the section dealing with the anatomy of the

1 From the photographs published by Klaatsch, Weltall und Menschhcit, Bd. ii.
p. 328, it is evident that the obliquity is much greater in the white than in the
dark Hominidae : thus a racial difference exists in respect of this character.

2 Cf. Chapter xvii. ; also Schwalbe : Der Neanderthalschadel.

312

COMPARATIVE OSTEOLOGY

[SECT. C

foetus. I cannot find evidence that either sexual or racial factors
influence these characters; in fact, as regards the angle of the
femoral neck, Rodet (quoted by Poirier) in a thesis on the femur
(Paris 1884) concludes that the angle is the same in both sexes.
Nor can any general statements as to sexual or racial differences
be based on the degree of torsion of the femoral shaft (Bertaux,
L’ Humerus et le Femur , Lille, 1891, quoted by Poirier). Finally,
though this is in some degree an anticipation of a future chapter,
the characters of the femora of the prehistpric (fossil) skeletons
known as those of Neanderthal and Spy (from the localities in
which they were found), are to be remarked as quite exceptional.
The chief peculiarities of these femora are the stoutness, the
comparative shortness, and the pronounced curve, with anterior
convexity of the shaft, with which is associated an unusually large
head. With these may be contrasted on the one hand, the fossil
femur of Pithecanthropus erectus (from Java), which more closely
resembles the common form of modern human femur in its

Fig. 202.

Fig. 200. Femora; (A) of H. neanderthalensis (Spy, No. 1) : (B) of H. sapiens.
Fig. 201. Femur of Pithecanthropus erectus, (.1) the anterior, (B) the external

aspect. , . .

Fig. 202. Femur of an Orang-utan (Hose donation ii) : this specimen is drawn
to a larger scale than the bones represented in Figs. 200 and 201.

CHAP. XIIl] COMPARATIVE OSTEOLOGY oL.J

proportions, and the femora of the Simiidae, which are dis-
tinguished by the relatively small size of the head, lhe ac-
companying figures provide a comparison of the femora of
H. neanderthalensis, of Pithecanthropus erectus, and of Simia
satyrus. (Figs. 200, 201, 202.)

(C) The presence of the so-called third trochanter constitutes a
striking femoral anomaly, but it must be pointed out that its
occurrence has not yet been demonstrated in association with
other racial differences: furthermore it is not a character approxi-
mating the Hominidae to any other family of the Primates: in
fact to find this third trochanter well-developed and constantly
present, one must pass to other Eutherian orders, and it will be
discovered as a very strongly marked feature in that division
of the Ungulata known as the Perissodactyla (or Ungulata with an
uneven number of digits, such as the Tapir, Rhinoceros, and Horse),
and it occurs again among the rodent Mammals.

(D) Extension of the condylar articular surface. Charles has
directed attention to the great upward extension of the articular
cartilage-clad surface on the posterior and upper aspect of the
internal condyle occurring in certain skeletons. Such extension
is by Charles1 associated with the high degree of flexion of which
the knee-joint is capable in the skeletons of races in which the
“squatting” posture is habitual. Thus the frequency and inten-
sity of this feature in the femora of the more primitive races
is explained. But observations are not sufficiently numerous to
lead to more specific statements than the foregoing.

( E ) The condition of Platymeria, or flattening of the femoral
shaft, now claims attention ; a considerable amount of literature
exists on this subject2. While the femoral shaft is, generally
speaking, cylindrical this statement really needs much qualification,
and departures from the cylindrical form are very definite indeed.
It must be at once stated that Platymeria implies flattening in

1 Journ. Anat. and Physiol., Vol. xxvn. p. 10.

2 See especially : (1) Turner, Challenger Report, xlvii. ; J. A. and P. xxi. (2) Hep-
burn: J. A. and P. xxxi. pp. 1 and 116, with full references. (3) Bumiiller, Das
Femur des Menschen, Inaug. Dissert. Munich. (4) Klaatsch, Anat. Heft, Band x.
1900, where extensive references will be found.

314

COMPARATIVE OSTEOLOGY

[SECT. C

two regions of the femoral shaft, viz., in an upper region, im-
mediately below the level of the lesser trochanter, and in a lower
region about 40 mm. above the highest level of the external
portion of the anterior aspect of the condylar articular surface.
These two regions may conveniently be studied apart.

It may be premised that the effect of Platymeria or femoral
flattening may be produced by either :

(1) Transverse widening of the shaft, the sagittal diameter
remaining constant.

(2) Sagittal reduction in thickness, the transverse diameter
remaining constant.

(3) A combination of transverse increase and sagittal decrease
in the dimensions of the shaft.

With these considerations in mind, the examination of a series
of femora selected from the Therian Mammals will shew that
Platymeria is by no means an exclusively human feature of the
femoral shaft, and that with regard to its occurrence the following
distinctions may be made.

(a) Theria in which the femur is not platymeric.

Metathcria. Macropus giganteus.

Order.

Eutheria. Bos. Ungulata artiodactyla.

Cervus elaphus. „

Hippopotamus. „

( b ) Theria in which the femur is platymeria

Eutheria.

Erinaceus.

Pinnipedia.!

Ursidae. J

Camelus.

Elephas.

Rhinoceros.

Order.

Insectivora.

Carnivora.

Ungulata Tylopoda.

„ Proboscidea.

„ Perissodactyla.

Moreover it is to be noted that such platymeria is the result
of transverse widening of the femoral shaft on its external rathei

COMPARATIVE OSTEOLOGY

315

CHAP. XIII]

than on its internal margin, which suggests further subdivisions of
Platymeria, for in Man either (1) external widening as a flange-like
process, or (2) internal extension, or (3) both forms of widening may
produce the effect. (Cf. Fig. 203.)

It is noteworthy that Platymeria
and the presence of a third trochanter
seem to be associated, since both charac-
terize the Perissodactyle in distinction
from the Artiodactyle Ungulata. In
human femora, too, the most platy-
meric examples usually possess if not
actually a third trochanter, at least a
very well marked gluteal line, such as
bears this trochanter when present; in
human femora which are not platy-
meric, the third trochanter appears
(from my observations) to be rare1.

In Artiodactylous Ungulates, the enor-
mous size of the great trochanter
seems to exist in compensatory relation
to the deficiency of a third trochanter.

The presence in lowly Eutheria of femoral flattening tends to
disprove its dependence on the erect attitude and the consequent
skeletal and muscular modifications; therefore we shall not be
surprised to find the condition in the Simiidae. Here, however,
some explanation is necessary. Compared with the human femur,
that of the Simiidae is flattened or platymeric in a general sense :
the linea aspera is less prominent, and is indeed often indis-
tinguishable; the shaft is consequently very flat, up to and about
its mid-point. Above this, however, the antero-posterior diameter
tends to increase and the transverse diameter to actually diminish;
further the shaft becomes more cylindrical, largely owing to
a buttress-like ridge which extends downwards from the lesser
trochanter, so that platymeria is often not marked in the same
region as in human femora. Platymeria exists, therefore, in the
femora of Simiidae, but it is characteristic of the lower parts

Fig. 203. Upper end of a
human femur: Platymeria may
be due to (1) extension outward
of a flange-like process (cf. the
flange-like process in humeri
of Gorilla and Megaladapis:) ‘x’
as in Eutheria: (2) extension
inwards as at ‘y’ in certain
human femora: (3) tx’ and ‘y’
may coexist in certain human
femora.

1 Only superior platymeria is here referred to.

316

COMPARATIVE OSTEOLOGY

[SECT. C

of the shaft, and the particular flattening that is comparable
to the superior platymeria of the human femur is frequently
lacking. It may occur however, as seen in the accompanying
tracings (cf. Figs. 204, 205), in
which the flattening seems due to
simple lack of development in the
sagittal direction, for no such
flange-like processes occur as have
been described in a preceding
paragraph; it would thus appear
that transverse increase in growth
is not the responsible factor. In
the femora of Gorillas a rudiment
of the external flange-growth may
occurwithout sufficient prominence
to produce the platymeric appear-
ance.

We are now prepared to con-
sider the occurrence of the superior
variety of Platymeria in the Ho-
minidae. While age (i.e. maturity)
appears a necessary factor in the
production of the character, sexual
influences seem quite obscure, though Manouvrier’s figures shew
that the tendency to flattening is slightly less in women than

Fig. 204. Fig. 205.

Fig. 204. Lateral (external) as-
pect of the upper end of the platy-
meric femur of an Orang-utan.

Fig. 205. Lateral (internal) as-
pect of the specimen represented in
Fig. 204. (Hose donation n. Mus.
Anat. Cant.)

men

An index of Platymeria has been devised, in which the trans-
verse diameter of the shaft is taken as = 100, so that the index

_ sagittal diameter x 100
transverse diameter

(the diameters being measured immediately below the lesser
trochanter).

The higher the numerical figure representing the index, the

1 (i) Congres international d’Anthropologie et d’Archcologie prdhistorique, 1889.

(ii) Bull, de la Soc. d’A. de Paris. Sdance du 23 Fdv. 1893, pp. 130 ct seq.

(iii) Bull, de la Soc. d’A. de Paris. Tome vi. S6rie iv. 1895.

CHAP. XIII] COMPARATIVE OSTEOLOGY 317

nearer is the approach to equality in the two diameters, and
consequently the less the platymeric condition will be manifested.
Manouvrier remarks that with the index below 80, the flattening
is distinct, and that with a figure less than 65 the character is
very pronounced.

The several series investigated shew that the condition is not
influenced by racial factors: and Manouvrier ascribes its cause to
physiological sources, appealing to the effects of over-use of
certain muscles. For the present purpose, then, the character
loses its interest, but from the point of view of the morphological
conformation of the femur it is of such importance that a sketch
of the views that are held regarding the action of those physio-
logical causes will be appended.

In expounding a theory of the causation of Platymeria Manouvrier has
called attention in the first place to the following point. Platymeria is due
to extension of the anterior surface transversely, not only relatively to the
sagittal diameter of the shaft, but absolutely, for the extension, which is first
marked in man on the inner side, may constitute such a flange-like projection

318

COMPARATIVE OSTEOLOGY

[SECT. C

as will obscure the lesser trochanter when the femur is viewed from in front
(Cf. Fig. 206 A, at.)

In consequence of such flattening, the surface of the femur gains in
proportion to the volume of the bone, and thus an extended area is provided
for muscular attachments. The muscles chiefly affected are the components
of the M. quadriceps extensor cruris (and that these are unevenly affected
in different instances is indicated by the occurrence of different kinds of
platymeria, which is not always constituted by strictly antoro-posterior
flattening, but oblique compression). The maximum degree of flattening
obtains when to the internal “flange” an external projection is added
(cf. also Fig. 206 B, where it constitutes one form of the 3rd trochanter) ; of
this condition a good example is the prehistoric femur from Crhcy (with a
platymeric index of f>6-4), a section of which is represented herewith
(Fig. 207). But the special point of Manouvrier’s
theory is that the action which thus causes these , ,

extensions is not the action commonly ascribed to
the M. quadriceps extensor cruris, viz. of extend-
ing the leg on the thigh, but the inverse action
of extending the body on the lower limb: this,

Manouvrier submits, occurs at each pace, in its

Fig. 207. Diagram of
a section through a very
platymeric human femur.

latest phase, and especially in the action of mount-
ing steps or steep slopes.

On these premises, Manouvrier has constructed
a theory to the effect that excessive use of the
muscles in question has resulted in their hyper-
trophy, and the consequent extension of their area
of attachment, which has been provided for by the
projection to which reference has been made.

This theory meets the facts that the condition is not influenced by racial
factors, and its author claims support on the ground that the same skeletons
present (1) platymeria, (2) the fossa hypo-trochanterica (seen immediately
beneath the lesser trochanter and bounded by the flange-like extension), and
(3) the lateral flattening of the tibia, called platycnemia, all of which are
attributable to the same cause ; further, that the associated conditions occur
in natives of mountainous regions.

While destructive criticism is notoriously easy, and though no other
theory has as yet been advanced with so much plausibility, nevertheless
the following difficulties must be urged against the acceptance of that brought
forward by Manouvrier.

In the first place, the sexual factor ought to be quite in abeyance, but the
figures provided by Manouvrier shew that this influence may quite possibly
be effective. Secondly, the condition is not shewn to be universally frequent
among mountaineers : admittedly it is so in femora of the extinct Guanche
race of the mountainous Canary Islands, but this does not explain the
presence of platymeria in ancient (prehistoric) French femora. Thirdly,

CHAP. XIII]

COMPARATIVE OSTEOLOGY

319

platycnemia may exist without platymeria (see under platycnemia).
Fourthly, the fossa hypo-trochanterica may also be present without coexistent
platymeria : and fifthly, the sporadic distribution of platymeria among other
Mammals does not favour such a limited explanation. Sixthly, the
comparison of the muscles of the thigh in such examples as Cercopithecus
and Man illustrates the behaviour of muscles when compared in two closely
allied forms, in which their relative development varies. The upper ends
of the femora of Man and of a Cercopithecus monkey are here represented
side by side (Fig. 208). The reciprocal develop-
ment of the M. crureus and Vastus interims is

for the M. crureus, which it apparently sup- areas of muscular attachments

plants and displaces. This consideration is of j;0 tlle anterior surface of the
1 , , , , . „ xl femur m (A) Man, (B) a Cer-

course not absolutely conclusive, tor the JV1. COpitheeus monkey.

crureus has presumably less tendency to assert

itself in the pronograde Cercopithecus than in orthograde Man; never-
theless it tends to the detriment of the theory. Seventhly, Macalister
points out that certain eminences, such as the so-called tuberculum quadrati,
may merely mark the limit of diaphysial and epiphysial ossifications, having
no significance with regard to the extent and physiological condition of
the (associated) M. quadratus femoris. Notwithstanding these drawbacks,
Manouvrier’s theory contains the only explanation of the condition as yet
proffered, and is accepted by Hepburn1. Turner2 seems to imply that the
habitual assumption of a squatting attitude can be appealed to as causal,
but the statement is not quite clear.

Platymeria has also been observed in the region of the
popliteal space of the lower end of the femur : here it is most
marked in the femur of the Gorilla (among Simiidae), to which
the Orang-utan comes next in order, followed by the Chimpanzee :
in the latter, the M. adductor magnus is largely inserted into the
popliteal surface, but Hepburn3 does not clearly state whether
this fact can be appealed to in explaining the somewhat raised

seen in the two cases ; in Cercopithecus, where
the M. vastus intern us has assumed consider-
able proportions, it is not accommodated with
a flange-like extension inwards of the femoral
surface, such as the theory postulates for an
exuberant M. vastus internus in the human
mountaineer; but it encroaches upon the area

Fig. 208. Diagrams of the

1 Journ. Anat. and Physiol., xxxi. p. 131.

2 Variations in the Skeleton, J. A. and P., xxi. p. 473.

3 Cf. Hepburn, The Trinil Femur, J. A. and P. , xxxi. Fig. 1, p. 16.

320

COMPARATIVE OSTEOLOGY

[SECT. C

character of the popliteal surface. This region has attracted an
unusual amount of attention in view of its condition in the Trinil
femur, the nature of which (as being referable to a member of the
Simiidae or Hominidae) has been the cause of so much discussion
in common with the associated remains (cf. Chapter xvn.). In
the Trinil femur the popliteal area bulges, lacking the flatness
so constant in normal human femora1 : Hepburn’s researches shew
that although the flattening is so constant, nevertheless exceptions
within the Hominidae do occur, constituting parallels to the
Trinil femur which ought not therefore to be regarded as abso-
lutely excluded from that family. And while Hepburn’s researches
revealed but few such exceptions, yet it is noteworthy that a
skeleton of an aboriginal of Australia provided the example in
which the condition of the Trinil femur was almost exactly re-
produced. It is only right to add, in illustration of the extreme
variability of the character, that this is a left femur, and that the
right femur of the same skeleton foils far short of its fellow in
this respect. In fact no racial variation was found, nor is the
condition dependent on sex or age, for which reasons it will not
here be further discussed. A variety of measurements of the
lower end of the femur were made by Bumuller in Ranke’s
laboratory at Munich, but have no bearing on the special subject
of the present chapter.

The Tibia. The principal variations in the form of the tibia
relate to

(A) The external portion of the upper articular surface.

(B) The backward curvature of the upper portion of the
shaft (and retroversion of the head of the tibia).

(C) The proportions of the sagittal and transverse diameters
of the shaft at the level of the nutrient foramen, and platycnemia.

(A) The external portion of the upper tibial articular surface,
or external condylar surface, upon which the external semilunar
cartilage rests, varies in convexity in the Simiidae and Hominidae :
a high degree of convexity is said by Thomson2 to characterize the

1 Pathological, e.g. rickety, femora may present such bulging in the popliteal
space.

2 J. A. andP., Vols. xxm. 610, p. xxv., and xxiv. 210, “Influence of posture
on the form of the tibia.”

CHAP. XIII]

COMPARATIVE OSTEOLOGY

321

former, and also the lower Hominidae : but the character is really,
in all probability, a physiological one, and associated with an
habitual “ squatting ” attitude : in such races, whatever their other
morphological characters may be, as do not habitually rest in a
squatting position, the convexity of the surface in question is less
pronounced.

The occurrence of a high degree of convexity is thus more
frequent in the black races than in the white, as the former group
contains more examples in which the squatting attitude is the
habitual resting posture. This posture is associated with an extreme
degree of genuflexion1. With the same excess of flexion at the
knee, would seem to be associated, the retroverted appearance
observed in certain tibiae, more frequently it is alleged in the
skeletons of squatting races, and with these characters is associated
again the existence of articular facets on the anterior margin of
the inferior articular tibial surface2.

(B) A retroverted tibial head would, according to Thomson,
probably coincide with a less pronounced articular convexity of
the surface just described, compensation being provided by the
retroversion. It is a noteworthy point that at one period such
retroversion of the head of the tibia on its shaft was thought
to imply that the individual presenting this appearance had not
yet attained the erect attitude fully : Manouvrier seems however
to have shewn that this inference is incorrect, and that the erect
attitude may be perfectly attained by an individual presenting
simultaneously marked retroversion of the head of the tibia. The
latter character is however associated with the extreme of genu-
flexion as just mentioned, and further, though less probably, with
what Manouvrier has described as “la marche en flexion” or walking
with the knee at no time fully extended. This particular gait
(which Manouvrier considers more frequent among mountaineers)
would accordingly be associated with platymeria, extreme power
and extent of flexion of the knee-joint, and platycnemia, or tibial
flattening from side to side.

To the accessory facets at the lower end of the tibia correspond

1 Thomson remarks its greater frequency in tibiae of fossil Man (op. cit.).

-Cl. Havelock Charles, J. A. and P. xxvin. p. 14; Arthur Thomson, op. cit.
ibid : and Baetz, Verliand. der Berliner Ges.fiir Anthr. 1901, s. 203.

D. M.

322

COMPARATIVE OSTEOLOGY

[SECT. C

similar facets on the outer side of the astragalar neck, which in
extreme flexion of knee and ankle come into contact with the
former, and are therefore regarded as witnesses to the squatting
habit, and as developed in relation therewith. Thomson clearly
distinguishes these external astragalar facets from others described
in cases of Talipes varus as occurring on the internal side of the
neck of the astragalus, not on its external surface.

The foregoing conditions constitute in some degree differences
between tibiae of the Simiidae and Hominidae. The former, as has
been remarked, present external condylar surfaces with pronounced
convexity, but do not appear to be characterized by retroversion
of the head of the tibia upon the shaft. With regard to accessory
inferior tibial and astragalar facets, the conditions in the Simiidae
vaiy, for the facets are said to be common in Simia and Gorilla,
but rare in Anthropopithecus. When present, they may be
associated with the freedom and extent of ankle flexion in
climbing movements'. Among the Hominidae, Collignon1 2 and
Fraipont3 have recorded the existence of retroversion of the head
of the tibia in the fossil human skeletons, particularly (Fraipont)
in the famous Spy skeletons. Charles4 has recorded the astragalar
articular facets referred to, in the skeletons of natives of India;
and foetal and infantile astragali of Punjabi natives in the Cam-
bridge Museum shew similar facets.

(C) Platycnemia or flattening of the tibial shaft is a very
striking anomaly, and has consequently attracted much interest.
The results of numerous investigations (chiefly conducted by
Manouvrier), tend to shew that the condition is to be regarded
as a physiological character developed in relation to environment
and habit. The flattening, it will be remarked, is in a plane at
right angles to that of the commonest variety of platymeria, and
in human skeletons the area of tibial attachment ol the M. tibialis
posticus is drawn backwards in the form of a keel or flange, which
thus increases the sagittal diameter of the tibial shaft, the tians-
verse diameter experiencing comparatively little change. It is

1 Cf. Thomson as quoted by Charles, J. A. and P. xxviii. p. 15.

2 Oollignon, Revue d’ Anthropologic, 1880.

a Fraipont, Revue d’ Anthropologic, 1887.

4 Charles, J. A. and P. xxviii. loc. cit. p. 15.

CHAP. XIII] COMPARATIVE OSTEOLOGY 323

undeniable that the affected part of the shaft lies posteriorly to
the interosseous membrane, and that in this respect the flattening,
or, as we may now describe it, the extension of the shaft differs
in the Hominidae, in which it is backward in direction, from the
apparently similar flattening, or extension of the shaft observed
in many instances among the Simiidae, in which however the
surface affected may be partly anterior to the line of the
interosseous attachments.

Manouvrier1 has made the following observations on the con-
dition of platycnemia.

(1) As regards the influence of age, the appearance of platy-
cnemia is associated with the attainment of maturity : absent in
childhood, it appears in later adolescence.

(2) As regards the influence of sex, it appears most marked
in male tibiae : and also associated with this observation is that
which records the greater frequency of platycnemia in short, than
in tall individuals.

(3) As regards the racial distribution of platycnemia, the
remark made by Manouvrier, to the effect that platycnemic and
non-platycnemic tibiae may occur in any population, would seem
to preclude us from the necessity of further considering the
character in the present connection. We will content ourselves
therefore by appending a brief note setting forth some of the
associated conditions.

Platycnemia is undoubtedly common in certain prehistoric
races of Western Europe and Egypt. In modern times it occurs
in a pronounced degree in rickety tibiae, and in the tibiae of
certain ill-fed and badly nourished Australian aboriginal tribes
(cf. the description of the “ boomerang ’’-tibia by Messrs Spencer
and Gillen, The Natives of Central Australia). Pruner-Bey at-
tributed all platycnemic cases to Rachitis (Rickets). Broca con-
troverted this view, and suggested that the condition is due to
enfeebled action of the muscles of the calf of the leg (the sural
musculature). Finally Manouvrier proposed his theory, which
exactly traverses Broca’s view, that over-action and not enfeeble-
ment, is the physiological cause, and that the muscle chiefly

1 Bull, de la Soc. d'A. de Paris , 4° S6rie, Tome x. p. 128, 1887.

21—2

324

COMPARATIVE OSTEOLOGY

[SECT. C

in question is the M. tibialis posticus. It is submitted that
examination of the associated conditions in the tibia reveals no
modification of the soleal line, either by way of increase or
decrease, so that the inference is that probably the calf muscles
were not enfeebled, as suggested by Broca. Again the area of
attachment of the M. tibialis anticus has undergone no change,
so that apparently no encroachment has occurred from this side.
Lastly however the area of attachment of the M. tibialis posticus
is found to be profoundly modified, and this observation led to a
theory of the production of platycnemia, based upon the views
held as to the action of the M. tibialis posticus. The argument
is set forth somewhat in the following way. The action of the
M. tibialis posticus is not always that of flexion with adduction
of the ankle-joint, for when the foot is fixed, the action of the
muscle will be reversed : taking its origin from below, the muscle
will tend to fix the tibia, and support it, especially where there
is slight extension of the ankle as in running and jumping.
Excess of this action would thus lead to hypertrophy of the
M. tibialis posticus, and this would be met by a corresponding
development of the osseous tibial attachment of the muscle, and
the consequent production of the posterial tibial crest or ridge,
upon which the occurrence of platycnemia depends.

The condition might hence be expected in any group or tribe
inhabiting a district which involved the exercise of much exertion
in locomotion. A mountainous district supplies such a necessity,
and the attempt has been made to shew that platycnemia is
especially frequent in races inhabiting mountainous districts.
This view is shewn by Charles1 to be inapplicable to the Punjabi
natives, nor can the great frequency of platycnemia in the
prehistoric tibiae from Egypt (in the Cambridge Museum) be
accounted for by the theory. There may be varieties dependent
on mal-nutrition; the sexual difference would be explained by the
greater muscular development and activity of the male: and the
platycnemia of the Simiidae is shewn to depend, not solely upon
modification of the area of attachment of the M. tibialis posticus,
but also to some extent on correlated modification in the area

1 J. A. and P. xxvm.

COMPARATIVE OSTEOLOGY

325

CHAP. XIII]

of attachment of the M. tibialis anticus, whereby it is differ-
entiated for human platycnemia. A satisfactory explanation of
platycnemia in the Simiidae may be found in an appeal to their
arboreal mode of existence.

The frequency of platycnemia, as well as of platymeria and
the conditions indicative that the squatting posture was habitual
in the prehistoric and fossil human races, is a remarkable fact, of
which no fully satisfactory explanation is as yet forthcoming.

An index of platycnemia is obtained as follows. Measurements
of the shaft are made at the level of the nutrient foramen, and the
antero-posterior and transverse diameters are compared, the antero-
posterior diameter being taken as = 100, and the index

transverse diameter x 100
antero-posterior diameter '

The following values are quoted by Manouvrier :

average indices: (10) modern French (men) 88-2

„ „ French (women) 806 to 108-3

„ „ (18) Negroes 85-3

„ „ (21) Pre-Columbian Venezuelans 76T,

while the following values for Mori-ori natives are from my
measurements upon specimens at Cambridge :

Skeleton A: right tibia, index 77'7.

Skeleton B: „ „ „ 66‘6.

Skeleton B: left „ „ 60,

the degree of flattening and platycnemia being very pronounced
in the latter example.

The Astragalus. In considering the astragalus, reference
must again be made to the supernumerary facets met with in this
bone in such races as “squat” (as well as in the foetus of such
races). Mention must now be made of a character which, though
not established as a differential racial feature, may yet be shewn
to possess such a value. This is the angle at which the neck
of the astragalus is set upon the body of the bone. The angle is
included by, (a) the line passing along the external border of the
neck, and (6) the line of the internal articular (malleolar) surface.
This character distinguishes the Hominidae clearly from the

326

COMPARATIVE OSTEOLOGY

[SECT. C

Simiidae, for in the latter the numerical value of the angle
varies from about 30° to 40°. Within the Hominidae the factor
of age is very important, for Shattock (quoted by Bland Sutton in
Morris’ Anatomy) has shewn its average value to be about 35°
in the foetus towards the end of pregnancy. In adults of white
races, the value has diminished
to about 10°. With regard to

qada race), viz. 18°. (Cf. Fig. 209.)

Calcaneum. The projection of the os calcaneum behind the
ankle has been described as characteristically great in the African
negro races. If the appearance be not altogether due to the
feeble sural musculature in those races'2, it should not be looked
upon as necessarily a feature denoting inferiority; for in the
comparison of the Simiidae with the Hominidae, a gradual
increase in the backward projection is to be noted, from Hylobates
and Simia in which it is minimal, through Anthropopithecus
niger, in which the heel begins to assert its future prominence,
and so through Gorilla, in which the human heel is clearly enough
foreshadowed, to Homo; a high degree of posterior projection must
therefore be regarded as an intensification of a character which
reaches its highest point in Man among the Primates. Other-
wise, the condition is not uncommon among Eutheria, and

1 Journ. Anat. and Phys. Vol. xxxviii., v. supra, Chap. vii. p. 176, footnote.
An exhaustive research on the form of the astragalus has been recently published
by Volkov, Bull, de la Sac. d'Anth. de Paris, 1903.

2 Topinard could make out no difference in the skeletons of white and black
races in this respect, but reserves judgement, stating that American observers have
demonstrated the excessive backward projection in living negroes (cf. El. d' Anth.
g6n. p. 1048). Laidlaw, Brit. Ass. Adv. Sc. 1904, stated that the heel-bone in
Egyptians is about 3 % longer than in white men.

sexual differences, information
is not forthcoming, and in re-
spect of racial variations is but
scanty. With the figure (10°)
just given for the white races,
there may however be con-
trasted the value recorded by
Sewell1 as the average in pre-
historic Egyptian astragali (Na-

Fig. 209. Astragali (of the left side)
of ( A ) Man, (B) Chimpanzee, shewing the
greater obliquity of the neck in the latter
form.

COMPARATIVE OSTEOLOGY

327

CHAP. XIII]

particularly among such as excel in speed, for the long calcanean
lever thus formed enables the sural group of muscles to act to
greater advantage, and this, it may be incidentally remarked, may
explain the feebler development of those muscles in such instances
as are accompanied by marked calcanean projection: in these, the
amount of muscle substance required would necessarily be less than
where less leverage is afforded by the conformation of the skeleton.

From the consideration of descriptive characters, we pass to
that of the proportions of the several skeletal segments, as
compared by means of measurements. The fundamental base or
canon of all such comparisons would seem naturally to be the
stature, but the measurement of this dimension in skeletons is
fraught with so much likelihood of serious error in observation,
that in the present account it will not be adopted. With
whatever canon that may be employed, it would be reasonable
to compare the length of such naturally demarcated portions of
the body as the limbs, the trunk, the head and neck. It will thus
be evident that a great number of comparisons might be instituted,
but only a selection of very modest dimensions will be submitted
for consideration in the present place, and we propose to limit the
list of comparisons to four, viz.:

(a) The length of the upper as compared with that of the
lower limb, exclusive in each case of the terminal portion (hand

i o . x • ,1 , - radial and humeral lengths combined

and foot); i.e. the relation, -r^-. . -=-* — — ^ .

tibial and femoral lengths combined

(b) The comparative lengths of proximal and distal segments

of the upper limb (without the hand); i.e. the relation, rr^ 1US .

humerus

of the lower limb (without the foot); i.e. the relation, J1—

lemur

( d ) The comparative length of the proximal segments of the
lower limb (femur), and of the upper limb (humerus); i.e. the

, humerus

relation, —z .

lemur

It will be noticed that the selection of the exact objects for
comparison has been somewhat arbitrary, but it can at least be

328

COMPARATIVE OSTEOLOGY

[SECT. C

urged that this selection is justified, both by the satisfaction of
morphological requirements and by the interest of the results
obtained.

The conventional measurements of the humerus and radius
are the maximum lengths of those bones placed in any position
whatsoever: but the bones of the lower limb require a certain
adjustment before the measurements can be made in accordance
with the method adopted by earlier observers. Thus the femur is
measured in what is known as the oblique position, i.e. the length
is measured between plane surface's, one touching both the
condyles, and the second parallel to the first, and touching the
head of the bone. The bone is best Measured upon a board with
uprights; the board used in the Cambridge laboratory has the
appearance shewn in Fig. 210.

A B

Fig. 210. Osteometric board used in tbe Cambridge Anatomy School.

The scale is fixed along the margin of the board: the uprights
A and B are set perpendicularly to the board and square to the
scale: and B slides along the board to and from A.

rphe maximum length of the tibia is not recoided, but the
length is measured between the upper articular surface and the
tip of the internal malleolus: the tibial spine on the upper surface
is thus excluded, and a cavity in one of the uprights admits of this
allowance being made.

For the sake of brevity, we may now indicate the lengths
of the several bones by initial letters, so that “ R is the length of
the radius, “Ii” that of the humerus, “ F” and “T” those of the
corresponding bones of the lower limb. “H + R thus denotes
the length of the upper limb (minus the hand), “F + T” that of
the lower limb (minus the foot).

The intermembral index. Our first investigation is directed
to the relation of H+R to F+ T as has already been indicated.

CHAP. XIIlJ

COMPARATIVE OSTEOLOGY

329

(£>

In an earlier chapter we have seen that the Hominidae are
distinguished by the great development in bulk and length of the
lower limb, as compared with the Simiidae, and that whereas in
the latter the combined lengths of humerus and radius exceed the
combined lengths of femur and tibia, the exactly converse relation
characterizes the Hominidae. Hut also it is known that the
Simiidae are not all characterized in the
same degree by this relation and that the
excess of fore-limb length over hind-limb
length is less in some species than others.

We have now to enquire whether the Ho-
minidae are uniform as regards the converse
relation, and whether there may not be
discoverable some such variation as has just
been noted in the Simiidae. To make the
results more easily comparable the method
of expression by means of an index has been
adopted and this is termed the “Intermem-
bral” Index. Considering the length of the
lower limb as= 100, the index

_ length of upper limb x 100
length of lower limb
(Cf. Fig. 211.)

We may first compare the Simiidae with
the Hominidae as regards this index: in the
former family the index provides values
which range from 141 in Simia (Humphry.

The Human Skeleton ) to 104'6 in Anthro-
popithecus niger1 : in other words, the com-

1 Other figures from observations on specimens at Cambridge may be here
appended, together with the results recorded by Humphry, and Turner ( Chall . lien.
xlvii. ).

Fig. 211. Diagrams
to represent the skeleton
of the limbs as compared
in the intermembral in-
dex : if the lower limb be
considered as of constant
length, the upper limb
may be relatively either
short as in (A), or long,
as in (B).

Hylobates :

Orang-utan :

Gorilla :

»»

Anthropopithecus Niger:

av. of 2 132-5 (W.L.H.D.

2 141 (Turner and Humphry.)

1 137-5 (W.L.H.D.)

3 119 4 (W.L.H.D.)

3 117 (Humphry).

3 104-6 (Turner.)

1 105-5 (W.L.H.D.)

1 103-5 (Humphry.)

The Chimpanzee is thus the most human, the Orang-utan the least human in
tins respect.

330

COMPARATIVE OSTEOLOGY

[SECT. C

bined lengths of humerus with radius exceed those of femur and
tibia by amounts varying from 4-l to 4-6 °/o- In Man, as we have seen,
the combined lengths of femur and tibia are in excess, and

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CHAP. XIII]

COMPARATIVE OSTEOLOGY

331

the index accordingly falls short of 100, and actually the range
observed is from about 66 to 67.

Within the Hominidae we must now consider the influences of
age, sex, and race, as in so many other instances.

Age is undoubtedly a most potent factor up to the time of the
appearance of the permanent teeth (7 — 8 yrs.). In a foetus of
four months and a half the very simian character of the proportions
of upper to lower limb-length is brought out by the intermembral
index: the value of this is 98'6, which is not so very remote from
the figure provided by the adult Chimpanzee (103'5 — 105-5); but
it is an individual measurement, and the value of the index given
by Sue’s figures (see chart A) is from 116 to 120, which surpasses
the index in the Chimpanzee.

The variations in the index from month to month in foetal life
may be conveniently displayed as a chart, and are represented in
the accompanying figures (A and B)1.

The gradual assumption of the human proportions is here
clearly shewn, and the second chart (B) carries the observations
on into post-natal life. The slight irregularity towards the end
of adolescence is due to the number of observations being in-
sufficient for uniformity to be complete. But the simian stage
was passed by the seventh month of foetal life.

The influence of sex must now be sought, and in adult
Europeans is seen to be practically nil, for, accepting Topinard’s
figures2 3, the average index for male and female alike is 69'5. As
regards race, the observations collected by Turner8 prove most
useful in demonstrating the differences which obtain. The follow-
ing values are quoted by Turner as averages computed from the
records of other observers as well as from his own work.

1 These charts are based upon data recorded or quoted by Humphry (The Human
Skeleton, pp. 110 — 111).

2 &l. d’ Antlir. yen. pp. 1040, 1041.

3 G 'hall. Bej). xlvii.

Aborigines of Australia
African Negroes
Andamanese ...
Europeans
Bush race

68-7

68- 9

69- 7
67-3

68—69

COMPARATIVE OSTEOLOGY

[SECT. C

332

Eskimo... ... ... 73-4

Lapps 72-8

Bambute Pygmies ... 83'6 (Shrubsall)1.

J — 1 — 1 — • — i — i — i — i — i — i — i — i_j » « » » *

t 2. 3. a s. & .7 a a ton. 1v13iAi5.i6.17.i8.Kpo.

Chart B.

Whence it appears that, while the Eskimo, Lapp and African
Pygmy races are most nearly allied to the Simiidae, yet the (adult)
Hominidae are as a group far removed from these : moreover the
white races occupy an intermediate position, and the black races

1 Cf. Johnston, The Uganda Protectorate.

CHAP. XIII]

COMPARATIVE OSTEOLOGY

333

of full stature have even shorter arms than these (in propotion to
their length of leg). It may at once be noticed that the Eskimo
index is the average of two individuals only, and may need revision ;
and in fact the Eskimo skeleton at Cambridge has an intermembral
index of about 69 (69'6 actually). The great length of upper ex-
tremity in the Eskimo is due to great humeral, not to radial length.
As regards the black races, the great length of lower limb in certain
of these, especially the Soudanese, is a matter of common know-
ledge, but at the same time it is a character which places them in
a category morphologically superior to that to which the white
races are to be relegated.

V 9

The radio-humeral index. The second relation to be con-
sidered is that of the radius to the humerus,
and this is commonly expressed in the form
of the ante-brachial or radio-humeral index,
derived from the formula (TI = 100)

Index = ™ -1-0 . (Cf. Fig. 212.)

The numerical value of this index in the
Simiidae ranges between 801 (in a Gorilla at
Cambridge), through 94-5 in a Chimpanzee
(Mus. Anat. Cant.) (Turner and Humphry1
give 94 as the average for Chimpanzees), and
1027 in Simia (Mus. Anat. Cant.), to 115‘5
in a Hylobates (Mus. Anat. Cant.). In the Ho-
minidae, the index rarely exceeds 81 (though
85-7 is on record), nevertheless the two families
overlap in respect of this index.

The modifications of this index in relation
to age and development within the Hominidae,
have been well demonstrated by Hamy (quoted
by Turner, op. cit.y, and the results obtained by that author shew
that the human foetus is in this respect distinctly simian up to
the mid-stage of pregnancy, after which the human proportions
are somewhat rapidly acquired. The index in the foetus at
2 £ months is said to be 88'8, and at the time of parturition the

Hl-Ji 3

Fig. 212. Diagram of
the bones as compared
in the radio-humeral in-
dex: the length of the
humerus being taken as
the constant factor, the
radius may be relatively
either short (A) or long
(B).

1 Op. cit. v. p. 331, supra.

2 Cf. p. 331, supra.

334 COMPARATIVE OSTEOLOGY

value has sunk to 76'2 (in white races). The
chart (C) gives an indication of the changes.

[sect, c
accompanying

CHAP. XIIl] COMPARATIVE OSTEOLOGY 335

The sexual difference in the proportion of radius to humerus
is very slight, but there is an indication that the radius is relatively
shorter in Woman: the difference in white races does not amount
to more than about '4 in the average value of the index
(72-5 J : 72-1 % ).

When we turn to the several human races, we find that, as
regards the figures representative of the index, examples such as
77'6 occur for an aboriginal of Australia, 68'6 for a Bushwoman
(both in the Cambridge Collection) while Turner (op. cit. p. 331,
supra ) has drawn up a three-fold classification of the human races,
based on the index, the dividing lines being at 75 and 80. Limbs
in which the index is less than 75 have relatively short radii, and
are furthest removed from the simian type : when the index is
between 75 and 80 the proportions are indifferent, but above 80
the radius is so long as to resemble that of the Gorilla, and in
a lesser degree those of the other Simiidae. Turner’s classification
may be given as follows :

Brachy-kerkic group. The radio-humeral index is less than 75.

Europeans (iv)1

Lapps ... (iv)

Eskimo... (vi)

Bush race (vii).

Mesati-kerkic group. The radio-humeral index is between
75 and 80.

Aboriginal Australians

(I)

Veddahs

Polynesians ...

(v)

African and Oceanic Negroes

(II and i)

African Pygmies

Yellow races

(IV).

Dolicho-kerkic group. The radio-humeral index is greater
than 80.

Andamanese ... (hi)

Some African Negroes (n)

Fuegians ... ... (iv)

and Simiidae in general.

1 The numerals refer to the groups described in Chapter xvi.

336

COMPARATIVE OSTEOLOGY

[SECT. C

The tibio-femoral index. The relation of tibial to femoral
length is expressed by the tibio-femoral index,
which is derived from the formula (F = 100)

Index = . (Cf. Fig. 213.)

The comparison of the Simiidae with the
Hominidae leads to the following conclusions
as to this index : the Hylobates and Orang-
utan are characterized by a relatively (to the
femur) long tibia, and though the Gorilla and
Chimpanzee are not usually so characterized,
examples (such as No. 3 W.L.H.D. priv. coll.)
occasionally present the proportion in ques-
tion. The figures collected by Turner
shew that the Gorilla and Chimpanzee
have a comparatively short tibia, with an
index below 83, this figure being occasionally
exceeded by the Orang-utan. This is the
case with at least one Orang-utan limb
(index 86'2) in the Cambridge Anatomical
Museum, also with one limb of Gorilla
(index 86T, as mentioned above), one
limb of a Chimpanzee (index 86-3), and more
definitely so with respect to two skeletons of
Hylobates (Hose Donation II., Mus. Anat.

Cant.), the figures being 89-9 and 90-3
respectively.

The higher the numerical value of the tibio-femoral index, the
more definitely simian are the proportions of the two bones in
question.

The influence of age in the Hominidae is illustrated by the
figures recorded by Humphry ( The Human Skeleton, p. Ill), and
an instance given of the index in a foetus of 4£ months (W.L.H.D)1;
the result is to shew that the human proportions are variable and
approximate on the average to the figure 80 as a mean in the
period from midway through intra-uterine life, to the attainment
of maturity. But no distinctly simian character in the foetus is

Fig. 213. Diagram of
the bones as compared in
the tibio-femoral index :
the length of the femur
being taken as the con-
stant factor, the length
of the tibia may be re-
latively either short ( A ),
or long (B).

1 Cf. Studies from the Anthropoloyical Laboratory , p. 18.

CHAP. XIII]

COMPARATIVE OSTEOLOGY

337

revealed by this series of figures, which has been plotted out in
the form of a curve in the accompanying chart D.

17)05.

^eors

A slight sexual variation is noticed, comparable to that which
is indicated by the radio-humeral index ; for the average value of
the tibio-femoral index in white women is less (80’8), i.e. they
have shorter tibiae relatively to the femoral length (for the work
of Manouvrier shews that they have shorter femora than men),
than white men (av. 81 -8) who are more simian than women in
this respect.

For the effects of racial variation, recourse must be had again
to the data collected by Turner1 who distinguishes races with a re-
latively short tibia as brachycnemic, from a dolichocnemic group :
the division is made arbitrarily at the figure 83, and the follow-
ing classification results :

A. Index below 83. Brachycnemic class: Europeans, most
yellow races, Eskimo.

n. m.

1 Chull. Rep. xi.vii.

338

COMPARATIVE OSTEOLOGY

[SECT. C

B. Index over 83. Dolichocnemic class : Aborigines of Aus-
tralia, Negroes, Andamanese, African Pygmies1, and probably,
though not certainly, Bush natives.

The humero-femoral index (often alluded to as the femoro-
humeral index). The femoro-humeral index
affords a means of comparing the relative
lengths of humerus and femur, and the femoral
length being taken as = 100, the index is
H x 100

(cf. Fig. 214). In respect of this

proportion, the Simiidae (with the exception
of the Chimpanzee) contrast strongly with the
Hominidae, for in the former the humerus is
actually longer than the femur. Specimens
in the Cambridge Museum yield the follow-
ing data: in Hylobates (av. of two) the index
is 117‘5 (the humerus is thus 17'5 °/0 longer
than the femur); in one Simia the index
is 126. The average value of the index in
three Gorillas is 12T5. (W.L.H.D. priv.

coll.) These figures are in accordance with
the records quoted by Turner, Flower, and
Humphry2. A Chimpanzee skeleton gives an
index of 101. Flower quotes 100 (equality 214‘ DiagramJ

in length) as the figure, but Turner and in the femoro-humeral
Humphry obtained figures of the values of £ the

97 and 98 respectively, shewing that in the femur being taken as
. . . the constant factor, the

Chimpanzee is seen the nearest approach to length of the humerus

the condition typical of the Hominidae; in j^or* long ^her

the latter the index is well below 100.

Within the Hominidae, the change in the proportion of humeral
to femoral length is represented diagram matically in the chart (E)
drawn up from data provided by Humphry3; the value of the
index is seen to be 81 '5 at birth : but at an earlier stage, viz. half-
way through the period of pregnancy, the foetus yields an index

1 Shrubsall, in Johnston’s The Uganda Protectorate.

2 In Turner’s Report on the bones of the human skeleton, Ghall. Rep. xlvii.

3 The Human Skeleton , p. 111.

CHAP. XIII]

COMPARATIVE OSTEOLOGY

339

The abscissae represent the age in years. It is remarkable that in all the charts,
with the exception of that relating to the Tibio-femoral index, the curve is of the
same character, viz. a curve descending from left to right. Moreover, the higher
points on the curve are those which approximate the Hominidae to the Simiidae
in the several characters investigated. It thus appears that in respect of each of
these, the condition is more simian in foetal and infantile life, the characteristic
human conformation being acquired with matui'ity.

22—2

340

COMPARATIVE OSTEOLOGY

[SECT. C

of 100, i.e. the humerus and femur are of equal length (foetus
in the Cambridge Anatomical Museum). The foetal condition
is thus distinctly simian, but by the time of birth the final human
characteristic proportion has been nearly attained.

From the data collected by Topinard1, it would appear that a
sexual difference exists, the male humerus being longer (for it is
improbable that the other condition to which the result might
be ascribed, viz. that the female femur were the longer; should
be the cause2), but the figures give rather conflicting results.

With regard to racial variations, numerous data have been
collected by Turner and others, from which it appears as though
the Central African Pygmies are the most simian of all Hominidae
in this respect (index 80-3).

Among the taller Hominidae, the Eskimo race present the
longest humeri and therefore the most simian character3, whereas
the white races are intermediate, and the black races least simian
in this respect.

With the humero-femoral index we conclude the account of
the proportions of the limbs and their chief segments as measured
in the skeleton. A general survey shews that the final condition
in Man is usually reached in the post-natal stages of growth and
that with regard to racial variations, there is no uniformity in
respect of the indication provided by the several characters. The
simian features are thus distributed irregularly among the human
races.

A factor that has not been directly discussed, but which is
a very important one, is that of absolute bulk as measured by
stature. For instance in comparing individuals of tall stature
with those who are short, no matter of what race, the tall person
owes his superior height rather to excess in length of the lower
limb than to excess of trunk-length. A tall person then (of any
race), tends to possess intermembral proportions indicative of short
upper and long lower limbs, and thus is far removed from the type
of the Simiidae, in which the upper limbs are long, and the lower

1 El. cl’ A. gcn£rale, pp. 1040, 1041. 2 Of. p. 337 supra.

3 It must be added that the skeleton of the Eskimo woman in the Cambridge
collection, does not bear out the above statement, the index is here 72-4, whereas

the average given by Turner is 77 '7.

CHAP. XIIl] COMPARATIVE OSTEOLOGY 341

are short. (Herein we may find the explanation of the position
of the tall negro races.) Again, when we dissect (so to speak), the
limb of the tall man, to find out whether both femur and tibia
have shared equally in the total increase to which the tall man
owes his stature, we find that the femur has increased to a greater
extent than the tibia. From this it follows that independently
of race, tall individuals will tend to have longer femora than short
persons, and the effect of this will be felt in the tibio-femoral and
humero-femoral indices, so that simply by reason of their stature,
the tall are less simian in proportions than the short, and so the
apparently paradoxical position of the black races as regards these
features and the corresponding indices may be explained.

Again, precisely similar considerations affect the influence of
sex, for the male being usually taller than the female, similar
differences (though unlike in degree) will be discovered, and in
this way sexual differences may be elucidated.

The differences obtaining in the two limbs, i.e. between the
right and left limbs must also be taken into consideration, but
the influence of this factor on the averages will be reduced by
increasing the number of observations.

The foregoing remarks on the proportions of the limbs are
suggested by exhaustive work on the subject by Manouvrier1 as
regards the differences due to right or left limbs being measured,
and a resume of researches is given by Turner2 in the monograph
so often referred to.

Limb-bones in relation to stature. This subject suggests the
consideration of the relation of the length of the limb-bones to
the stature, and the problem of the reconstruction of the stature
from the length of one or more long bones of the skeleton. It
must be premised that such reconstruction can only amount to
an approximation, owing to the wide range of individual variation.
A simple method of arriving at a result is to measure a series of
cadavera, and then to remove, clean, and measure the limb-bones,
when average values for the stature and for the length of each
bone will be obtained. The quotient obtained by dividing the

1 M6m. de la Societe d’A. de Paris , Tome iv. p. 347.

2 Chall. Rep. xlvii., “Bones of the Skeleton,” p. 103.

342

COMPARATIVE OSTEOLOGY

[SECT. C

average stature by the average length of any bone, provides a
coefficient for that bone, which will serve for the reconstruction of
stature when the corresponding bone of a skeleton of unknown
stature is to be investigated. The formula is thus as follows:
Probable stature = Length ( L ) x coefficient. It is quite evident that
this would give a very rough approximation only, for the stature
obtained would be the average stature of individuals whose average
bone-length had provided the coefficient used, and the individual
stature might perhaps be very different from the average. Besides
this, the coefficient is found to vary with the absolute stature,
being different in short and in tall individuals, and also in the two
sexes. Manouvrier1 provided corrections for these errors which
made closer approximations possible, and the coefficients are
published in that author’s monograph dealing with this subject.
It is to be noticed that in these researches, it is postulated that
the relation of the length of any bone to the stature is a simple
one expressible by the formula

Stature = Length of bone x coefficient for that bone, or S = L x x.

But later writers urge that the relation is not so simple, and
that a more correct expression is given by the formula

S = L x x 4- x,

and the value of both x and x will depend upon various con-
siderations, such as sex, race, absolute bulk, etc. Formulae of
this latter type have been published by Pearson, and may be found
in his contribution to the “ Reconstruction of the stature of pre-
historic races2.” These formulae are similar to those provided for
the determination of cranial capacity from the dimensions of
length, breadth and height of the skull as described in Chapter XI.

Anthropometry. The foregoing method of investigating the
characters of the limb bones so far as regards their proportionate
lengths, is applicable with modifications to the living individual.
The most interesting measurements in Anthropometry are ac-
cordingly those which provide a means of comparison of vanous
individuals by means of the proportions subsisting between their

1 Manouvrier, MAm. de la Soc. d’Anth. de Paris, Tome iv.

2 Pearson, Phil. Trans. Part A, 192, pp. 109 et seq.

COMPARATIVE OSTEOLOGY

343

CHAP. XIII]

limbs and the different segments of the same. It seems appro-
priate to add in this place a brief account of the principal
measurements to be made on living subjects. The instruments
needed are (1) a long graduated rod such as is provided in
Martin’s traveller’s anthropometric outfit, with (2) callipers, and
(3) a head-spanner like those of Cunningham or Pearson1. The
following measurements are recommended as of the first importance.
The subject to be measured stands erect, and if possible the head
is fixed, so as to bring the base-line (from the lower orbital margin
to the upper margin of the external auditory meatus) into the
horizontal plane.

A. The Head, (i) Horizontal circumference : measured as
upon the skull : the maximum circumference in a horizontal plane
being recorded.

(ii) Length : the maximum length, measured (as nearly as
possible) as on the skull.

(iii) Breadth : the maximum breadth, measured as upon the
skull.

(iv) Height : the basal height can only be arrived at by very
special methods. Hepburn2 has devised a special craniometer for
the determination of this dimension. Ordinarily it is better to
substitute the auricular height, measured as upon the skull, with
the head-spanner.

B. The Face, (i) The nasal radius (or auriculo-nasal line) :
this is measured with the head-spanner, and is the distance of the
nasion from the inter-auricular line.

(ii) The prosthionic radius (or auriculo-prosthionic line) : this
is measured with the head-spanner, and is the distance of the
prosthion from the inter-auricular line.

From the two foregoing measurements, an indication of the
prognathism (or the reverse) of the individual can be obtained :
an alveolar index for the living subject may be constructed, sub-
stituting the prosthionic radius for the basi-prosthionic length,
and the nasal radius for the basi-nasal length. Nelson Annandale
( Proc . Roy. Soc. Edin. XX v. p. 12) has recently investigated the

1 Cf. Figs. 167 and 168.

2 Proc. Roy. Soc. Edin. xxii. also Waterson, Journ. Anat. and Phys. xxxiv. p. 57.

344

COMPARATIVE OSTEOLOGY

[SECT. C

relation between the radii (such as the basi-nasal and basi-
prost bionic lines) drawn from the basion, with the inter-auricular
radii, as measured with Pearson’s head-spanner.

(iii) The nasal length : measured from the line joining the
eyebrows to the nasal spine, which can be felt subcutaneously.

(iv) The nasal breadth : measured across the alae nasi : in
laughter, this diameter is falsified and increased.

(v) The facial height: from the line joining the eyebrows,
to the prosthion, which is exposed when the upper lip is retracted.

(vi) The facial breadth : the maximum bizygomatic breadth.

C. The body as a whole.

1. Height : the subject stands erect, the base-line of the head
being in the horizontal plane.

2. Height of chin: the subject stands as in No. 1.

3. Height of pre-sternal notch : the latter is felt subcu-
taneously, the subject standing as in No. 1.

4. Height of acromion process : this point is felt subcu-
taneously, the subject standing as in No. 1.

5. Height sitting: the subject holds the head as in No. l,and
the buttocks are approximated to the measuring rod.

6. Height kneeling: the head is held as in No. 1.

7. Pleight of knee : measured to the lower margin of the
patella, the M. quadriceps extensor cruris being contracted.

8. Height of the internal malleolus of the ankle.

9. Length of arm: from just below the acromion process, to
the depression which is bounded above by the external epicondyle
of the humerus : this gives the humeral length.

10. Length of forearm : from the depression (mentioned in
No. 9), in which the head of the radius can be felt; to the tip of
the radial styloid process.

11. Length of the hand : from the line joining the tips of the
radial and ulnar styloid processes across the dorsum of the wrist,
to the tip of the middle digit.

12. Length of the foot: the maximum length, measured
when the subject is leaning forward, so that the toes are not
flexed.

13. Biacromial breadth : from one acromion process to the
other.

COMPARATIVE OSTEOLOGY

345

CHAP. XIII]

14. Bitrochanteric breadth : from the great trochanter of one
side to the corresponding point on the other side of the body.

The foregoing measurements provide material for the consti ac-
tion of diagrams such as that which follows, which is drawn in
comparison of similar figures published by Thomson in Knoiuledge.
(Cf. Fig. 215.)

CAUCjssym. [A/ffiLO-jwEWOANia. ^eg^o. <L esjojao.o.

pangan.6. pakgan.2.

Fig. 215. Diagrams showing relative proportions of average Caucasian, Negro,
Eskimo, Pangan Semang (male), and Pangan Semang (female).

It will be noticed (with regard to the segments of the limbs),
that whereas the humeral, radial, and tibial lengths can be
ascertained with a fair degree of accuracy, the femoral length is
very much more difficult to measure, and hence is represented
only by the difference between the kneeling and sitting heights.
But although the difference is not equal in amount to the femoral
length, it nevertheless is an amount that will vary directly with
the femoral length and therefore is useful from the point of view
of comparisons.

CHAPTER XIV.

the comparative morphology of the soft tissues.

The Skin. From the skeletal structures, attention is now
to be transferred to the soft tissues, among which the skin may
conveniently be first considered. Next in order will be taken the
hair and other dermal and epidermal appendages. Apart from the
hair, the most important feature in the study of the cutaneous
system is its pigmentation, with particular reference to the nature
and distribution of the pigment. As regards the former subject,
the pigments of the skin, though varying in nature in different
races, agree in possessing certain characters in common, which lead
to their association with other animal pigments in a group known
as that of the Melanins (a generic name for epiblastic pigments).
Melanin is regarded as the oxidised derivative of a colourless
precursor called Melanogen ; melanins are insoluble in alcohol,
ether, and chloroform, but soluble in alkalies (and also in strong
sulphuric acid. Sorby)'. They contain iron and sulphur in addition
to the ordinary constituents of organic matter, but yield no definite
spectrum. Melanins occur (in nature) principally in epiblastic
structures, such as the skin, the hair, in the retina, especially in
the choroid layer. These pigments appear to be functionally
associated with the action of light, as is shewn by their constant
(or almost constant) presence in dioptric mechanisms in animals,
by the phenomena of sun burn, and of freckling2. But they also
would seem related to degenerative processes, as exemplified by
their presence in certain varieties of scars, in some cases of burns2,

1 Journal of the Anth. Institute, Feb. 12, 1878.

2 Baelz (Z. fiir Ellin. Bd. xxxm., S. 204) gives some suggestive information on
this subject.

THE SOFT TISSUES

347

CHAP. XIV]

in certain regions of the nervous system such as the sympathetic
ganglia or the substantia nigra, where the association is pre-
sumably with vestigial structures which may be considered as
degenerated if not degenerating ; in the organisms of malaria1;
and finally pigmentation is undoubtedly produced pathologically
by such influences as certain toxic drugs, by altered metabolism,
as in disease of the suprarenal bodies, or the production of cell-
tissue of low vitality as in the case of melanotic sarcoma, in
association with which growth melanin is excreted in the urine,
to which it imparts a characteristic tint.

The action of the drugs which produce toxic pigmentation such
as arsenic, is probably different from that of silver, for the latter
supplies a main constituent of the pigment observed.

As arsenic has been shewn to arrest the glycogenic function of
the liver (when given in pigment-producing doses) so that the
“ diabetic puncture ” is no longer effectual, a suggestion is thus
provided that the pigmentation maybe derived from bile-pigments:
certainly it appears that melanin may thus be derived, since it
occurs in the urine in certain forms of malarial fever (black-water
fever1).

The association of pigment formation (which may be extremely
marked in cases of Addison’s disease) with the suprarenal bodies,
is still obscure. Tizzoni suggests that the normal action of the
suprarenal bodies is to prevent pigment formation, and that the
pigment appears when this normal function has been lost in
consequence of the diseased state of those bodies.

Melanotic sarcoma most commonly originates in tissues in
which pigment is plentiful, such as the choroid layer of the eye :
but the secondary growths are characterized by the production of
immense quantities of melanin in situations (such as the peri-
cardium) in which its appearance is abnormal.

But it is necessary to return from this digression to the
consideration of the occurrence and position of pigment in the skin.

The colour of the skin has been accepted from time immemorial
as a distinctive racial character, and from the survey of osteological
characters just completed, it will be seen that the distinction based

1 Melanin was first described in this connection, having been recognised in 1849.
The names of Virchow, Frerichs, and Meckel are noteworthy in this connection.

348

THE SOFT TISSUES

[SECT. C

on this test holds good in many features derived from at least one
other anatomical system in addition to the cutaneous one. Many
years ago Sorby1 conducted researches on the varieties of pigment,
finding three easily recognisable, viz. : a yellow pigment, a reddish-
brown, and a black pigment. The so-called fair races normally
possess so little of the two former varieties, that the pink coloration
dependent on the superficial blood capillaries is hardly obscured :
but exposure to light may increase the amount so as to obscure
the normal pink tint, either universally as in ordinary bronzing
from exposure to the sun or locally as in freckling.

In the yellow races, the two former pigments are normally
present in such amounts as to obscure the presence of capillary
vessels, and in the black races this effect is absolutely completed
by the additional presence of the black melanin.

The pigment is usually confined to the lowest layers of the
stratum mucosum, but in the black races may extend beyond this
to a variable extent. Breul (Morph, arheiten, Bd. vi. 3, quoted
by Deniker) records the occurrence of pigment even in the
corneous stratum, and on the other hand in the dermis: and
Adachi (Zeitsch. fur Morph, und Anthropologic , Bd. v.) also describes
the wide distribution of pigment. Thomson remarks that the term
“ black ” used in classifying races, is one of considerable latitude,
for Sorby ’s results shew that (i) of two samples of hair of equal
intensity of blackness, one may contain thrice the amount of
pigment found in the second, and that (ii) certain samples of
negro hair, while yielding abundance of black pigment, contained
at the same time as much of the brown-red pigment as an equal
weight of red European hair. For the present purpose, these
conclusions from data relative to the pigment of the hair are
applicable to the skin, the pigments being identical. In the
black races the red pigment maybe in excess and thus is explained
the paradoxical occurrence of “ red ” negroes in the heart of the
African continent, as in the Welle region (Fan and Nyam-Nyam
tribes). Reddish hair has been noted among negro tribes, but care
and discrimination are advisable before accepting statements ot
the kind, for the discoloration of the hair by means ot lime is not
uncommon among savage negro tribes.

1 Sorby, Journ. Antli. Institute, Feb. 12, 1878.

THE SOFT TSSSUES

349

CHAP. XIV]

The difficulties in the way of an accurate comparison of
individuals of the more deeply pigmented races, are quite ignored
by the current method of recording the colour of skin and hair :
this consists simply in comparison with a numbered series of
tinted sheets of paper, so that the observation takes the form of
a numeral indicating the tint most nearly corresponding to the
observed colour1. The method is arbitrary in the extreme, for the
standard tints are limited in number to about forty.

The balance of opinion inclines to the view that the pigment
is brought to the cells as such, and is not elaborated by them. The
view has been advanced by Thomson ( Knowledge , I. 2. 99) that the
growth of the epidemic cells does not take place uniformly from
the deepest la}’ers upwards, but that the strata lucidum and
granulosum are dividing layers, the cells of the former being the
most superficially in direction, those of the latter being directed
towards the Malpighian layer. But Breul’s record (v. ante) of
pigment in the stratum corneum seems to constitute an argument
against Thomson’s theory.

With regard to the distribution of pigment, it is to be noticed
that even the fairest races present areas in which an accumulation
of pigment is common, though the difference in intensity of pig-
mentation may be slight. Generally speaking, dorsal surfaces are
more darkly pigmented than ventral surfaces, and particular
regions such as the axillae, scrotum, perinaeum and the mamillae,
are also characterized by darker tints which are not, as might be
expected, diminished in intensity by protection from the action
of light. The slighter pigmentation of the palmar and plantar
surfaces in negroes is a matter of common knowledge.

Finally as regards the loss of pigment and the whitening of the
hair, Metschnikoff’s researches may be mentioned. This observer
has shewn that the pigment in the hair shaft is removed by certain
of the intrinsic cells of the hair which become actively pigmento-
phagic. (Cf. Metschnikoff, Ann. de VInstitut Pasteur, 1901, p. 865.)

1 The same objection may be urged against Rivers’ method of rotating discs with
sectors of varying shades. Thomson’s suggestion is logical, but difficult to carry into
practice: it is that (as regards hair) the amounts of pigments from equal weights of
material should be compared. This process is protracted and needs reagents and
chemical apparatus not easily transportable.

350

THE SOFT TISSUES

[SECT. C

Following the method of procedure hitherto adopted, we may
institute in the first place a comparison of the Simiidae with the
Hominidae in respect of skin colour. In both primate families
alike, variations in this respect are very pronounced ; corresponding
to the yellow and black human varieties, we may cite the yellow-
skinned Simia (Orang-utan) and the black-skinned Hylobates or
Gorilla. No exactly corresponding type to the fair-skinned Homi-
nidae is in existence. Anthropopithecus niger (the Chimpanzee)
demands a special notice: the distinctive adjective must be taken
to refer to the colour of the hair rather than that of the skin, which
in the young is yellowish, becoming freckled, with darker blotches,
in the mature stages, while in aged individuals the freckles fuse
(at any rate on the face) to form a uniform black skin : even in
aged individuals, such fusion is often incomplete at the extremities,
and an old Chimpanzee in the Cambridge Museum shews that the
blotched condition may be retained throughout life. In contra-
distinction to this, the skin of the Gorilla is uniformly black from
the earliest post-natal stages known, though in the 5th-month
foetus examined by Deniker1 (the colour resembled that of “caf6
au lait”), and in the younger (4£ month) foetus described by the
writer, pigment had not yet asserted its presence in the skin. In
these examples, a certain modification may have been produced
by long sojourn in alcohol.

Within the Hominidae, the influences of age and sex can only
be satisfactorily studied in the more deeply pigmented races.

The influence of Age. The newly-born infant of white parent-
age is often characterized by an almost brick-red coloration, but
though this might be claimed as a reminiscence of a pigmented
phase in the ancestry of the white races, its occurrence may be
also associated with the foetal mode of respiration and its effects
on the tint of the blood. In reference to intermediate grades
of pigmentation, it is a matter of some surprise that the offspring
of white and black parents should so rarely be “piebald.” Deniker
cites instances2 of the occurrence of temporary patches of pigment

1 These de Paris, 1885.

2 Baelz, Mitt, deutscli. Qesell. Nat. unci Vollcerk. Ostasiem, Vol. iv. p. 40;
Matignon, Bull. Soc. d’ Anth. de Paris, 189G, p. 524; Colliguon, ibid. p. 528;
Soren-Hansen, Bidrag Vestgrbnland. anthr., Copenhagen, 1893.

CHAP. XIV]

THE SOFT TISSUES

351

in the sacro-lumbar (dorsal), gluteal, or perinaeal regions in new-
born infants amongst the Japanese, Chinese, Tagals of the
Phillipines, and Eskimo. Still more recently, Lehmann-Nitsche
has published ( Globus , Band, lxxxv. No. 19), an exhaustive list
of references, shewing the widespread occurrence of the phe-
nomenon among the Hominidae.

With regard to the foetus, and even the newly-born child,
among the Negro races, the opinion was long held that the
characteristic colour was not present in those early stages. We
may notice in this connection two researches, viz. that of Falken-
stein, on the colour of the new-born infant in negro tribes; and
that of Thomson1 on the histology of the skin of the negro foetus.
There seems no doubt that the negro infant at birth has not yet
acquired the full intensity of pigmentation which it will sub-
sequently assume. Falkenstein (whose observations were, be it
remembered, carried out in the region of the Cameroons where a
number of bronzed and even mottled negro types occur), notes that
while the general colour of the newly-born infant is dusky red,
not unlike that of some new-born white infants, yet at the same
time, certain regions are already more distinctly and darkly
pigmented. Such regions comprise (a) the dorsal surface in
general, ( b ) the auricles, (c) the mammillae, ( d ) the region of
the umbilicus. The same observer notices that the plantar
surfaces are unusually light in tint, and indeed these, and the
palmar surfaces, never attain to the same intensity of pig-
mentation even in the darkest negroes. Incidentally, it may be
noted that the colour of the iris is not in that stage blue, as had
been stated, but already brown, as in the later periods of growth.
Falkenstein observed that in six weeks time, the true negro
coloration was fully acquired, and thus the result differs from the
observations of Pruner-Bey on negroes of the Soudan and lower
Egypt, where one year and three years respectively were necessary
for the full attainment of the character.

Thomson records the occurrence of pigment in the skin of
foetuses of negro parentage, at ages from 5 — 8 months, and adduces
Morison’s evidence in support of these observations. It is remark-
able that in the earlier stage (5th month) the pigment is more

1 Journ. Aiiat. and Phyts. 1891.

THE SOFT TISSUES

352

[sect, c

pronounced in the scalp, whereas at the 9th month no such
predominance is observed.

Among other races, Chinese, Botocudos (Brazil), Malays, and
Kalmuks are stated by Deniker (without specific references
however) to be lighter at birth than in subsequent periods.

Sexual variation in pigmentation is a subject upon which more
information is required before general statements can be made
with confidence. While the general rule is that women are lighter
in colour than men, thus possessing an infantile character
(Deniker), notable exceptions occur, and cutaneous pigmentation
has almost certainly some relation, though in nature obscure, with
the functions of the genital system in females of white races.

Racial Variation. Finally we come to the racial factor in the
distribution of pigmentation among the Hominidae. We have
already noticed the distinction of the three main varieties of
pigmentation, and remarked that other distinctions of a morpho-
logical nature accompany this (which might quite possibly be
considered of physiological origin). We must here notice certain
marked exceptions to this statement. For if we examine all the
negro races known to us, we find that some of the most intensely
black individuals are literally only “skin-deep” negroes and that
judged by their osteology, and as far as is known their mor-
phology as a whole, they are associated with races of white colour.
As instances, the ebony-black Bishari tribes of the Soudan (closely
associated geographically with the Soudanese negroes), and certain
Abyssinian “Hamitic” tribes may be adduced.

Again, judged by the test of skin-colour, the Bush natives of
South Africa would be associated with the Yellow races; but in
the Bush native, these, which may be called Mongolian affinities,
are also skin-deep only, and otherwise the general evidence of
morphological conformation assigns to that race a most definite
and almost isolated position, which is not adjacent to those
occupied by yellow races.

Used alone therefore, the test of colour will lead to serious
misapprehension of the real relations of various races, and tempting
though its application is, it must, for the above reason, be relegated
to a secondary position in the list of test-characters adopted in the
attempt to classify the Hominidae upon a morphological basis.

THE SOFT TISSUES

353

CHAP. XIV]

With the remark that in colour-classification we may recognise
three groups with the oldest observers, five groups with Blumen-
bach, ten with Topinard1, or about forty with Broca, we must now
turn to the consideration of the characters of the hair.

The Hair. A comparison of the hairy covering in the Simiidae
and Hominidae reveals at once two striking facts: (a) the reduction
in the extent of the hair-clad surface in the Hominidae2, and (6) the
no less remarkable sexual difference in the Hominidae, which is not
observed in the Simiidae with the exception of Simia. The latter
(the Orang-utan) presents us with the example of the greatest
development of the hair, if we consider its general distribution,
while at the same time this animal often shews a lack of the
characteristic human feature of the development of the hair over
the vertex of the head, a character shared by certain varieties
of Chimpanzee, but not by Hylobates nor by Gorilla. Hylobates
differs from the other three members of its family in respect of the
direction of the hair-tracts of the upper extremity3 which are

1 The ten varieties proposed by Topinard may be enumerated as follows:

! 1. pale, as in many Europeans.

White -

florid, as in Scandinavians.

olive-white, as in Italians and Levantines.

4‘

clear yellow, as in Chinese and probably in Bush natives.

Yellow

1 5'

olive-yellow, as in Polynesians.

dark yellow, as in Malays.

r 7.

coppery-red, as in Nyam-Nyams.

chocolate-brown, as in aborigines of Australia.

Dark

sooty-black, as in African negroes.

10.

coal-black as in Bisliaris, and Oceanic negroes, as well as

k African negroes.

2 Cf. Flower, Romanes, also Kidd, Journ. A. and P. Vol. xxxv. p. 305. In
the latter paper (upon the direction of the hair-tracts) Kidd suggests that Voigt’s
theory (that the determining factor is the growth of the skin, which occurs unevenly
in different directions at various periods), is less probably correct than the ex-
planation which calls to account the action of gravity, combined with the effect of
habitually-repeated movements pressing the hair into the several tracts observed.

3 This reduction of the hairy covering is not so uncommon among Mammals as
might at first appear. Thus the order Cetacea is characterized by the complete
absence of hah- among its members, if we exclude baleen from that designation.
Many Ungulata, such as Elephas and Hippopotamus, are hairless or nearly so:
the Sirenia are almost hairless, and so are certain Edentata, Cheiroptera, and
Carnivora. Absence of hair and hair-follicles from the terminal phalanges of the
digits was recognised by Romanes as a distinctive “ordinal” character of the
Primates. Cf. Life of Romanes, p. 297. (Letter to Schafer.)

D. M.

354

THE SOFT TISSUES

[SECT. C

uniformly directed towards the wrist, whereas in the other
Simiidae and in Hominidae convergence on either side towards
the elbow is found. In the Simiidae and Hominidae alike, hair-
tracts diverge from the knee, passing up and outwards on the
outer surface of the thigh, down and outwards along the outer
surface of the leg. There is (with the above-mentioned exception)
a very general agreement between Simiidae and Hominidae
regarding the disposition of hair-tracts and vortices (for further
discussion of these cf. Wiedersheim, Structure of Man , Engl,
trans. pp. 4 et seq.)\ Within the Hominidae, the influences of age,
sex, and race will now be considered.

The foetus, at the later stages (e.g. the sixth month) of intra-
uterine development bears the extensive lanugo-covering, which
is, however, shed before birth, so that the newly-born child is
to all appearance almost entirely destitute of hairy covering: the
hair on the head is short and soft, and a close inspection will
usually lead to the detection of a fine down-like hairy covering
which is very general over the surface of the body.

Sexual differences in the hairy covering demand but scanty
notice here: and we may notice that the familiar sexual difference
observed in the white races is noticed generally in the Hominidae.
Sporadic examples occur (among the white races) of unusually
hirsute females, especially perhaps among the brunette races of
Southern Europe, but this cannot be claimed as a trait allying the
races in question to the black races, in which this feature is not as a
rule pronounced. Age seems to have some influence, and occasional
instances of excessive development of a beard, even surpassing that
normal in males, are on record as occurring in .females of white
races, but such instances are commonly regarded as verging on
pathological varieties.

It seems appropriate in this connection to call attention to
the not uncommon occurrence of long tufts of hair growing from
pigmented naevi or “moles.” Such instances are associated with
some local deviation from the normal course of development, and
are not distinctive of sex or race. Bland Sutton quotes cases of
the association of long tufts of hair with imperfect closure8 of the

1 For further researches on the direction of hair-tracts, see various papers in the
Proc. of the Zool. Society by W. Kidd, F.Z.S. 1890 et .icq.

2 See also Mayet, Z.fiir Ethn. Band 33, s. 42G, on sacro-lumbar hypertrichosis

CHAP. XIV ] THE SOFT TISSUES dOO

neural arches of the vertebral column1. Similar trophic aber-
rations may be called in question to explain the occasional
excessive hirsuteness of individuals of feeble intellect.

The ordinary racial variations m the extent and the disti lbution
of the hair are so well known as to call for merely a buef
recapitulation here. The range of variation is extreme: on the
whole the yellow races are the least hirsute: to these the black
races come next in order (with some remarkable exceptions), and
the white races must be reviewed to discover the examples of the
highest development of this character. These remarks apply not
only to the hair of the head but also to the hair of other regions,
such as the axillae and pubes2. The hair when abundant is
usually more plentiful on the anterior (ventral) than on the dorsal
aspect: but occasionally one may see examples of white men with
an abundant crop of hair over the scapular regions.

The excessive hairiness of the Ainus, or Ainos (the aboriginals
of the northern islands of the Japanese group) has long been
notorious. It may be mentioned that these aborigines are asso-
ciated by the characters of the hair, as well as in certain other
respects, with the white races, rather than with their Mongolian
neighbours 3.

The aborigines of Australia present the extremes of hairiness
and its reverse, for while Miklucho-Maclay4 has recorded the
existence of practically glabrous natives in Australia, the explora-
tions of Spencer and Gillen5 have revealed the presence of
individuals rivalling the Aino in hirsuteness. The Todas of
Hindustan may be cited as further instances of pronounced
hirsuteness in darkly-pigmented races.

The dwarf races as a rule retain the infantile character of

as a sign of degeneracy. Many references are appended. In the same volume,
Baelz discusses the hirsuteness associated with cachexia (ibid. p. 209).

1 Evolution and Disease, p. 23.

2 Cf. Strauch, Z. fiir Ethn. Band 33, s. 534.

3 Recent researches, summarised by Koganei, shew that there is a good deal of
reason for regarding the Ainos as having been present in the Japanese region since
the neolithic period. Cf. Koganei, Mitt, der Deutschen Ges. fiir Nat. und Vblker-
kunde Ostasiens, Bd. ix. Teil 3, abstracted in Man, 1903. Baelz, Z. fiir Ethn.
Band 33, s. 209, states that the Ainos retain the lanugo much longer than
Europeans.

4 Sitz, der Berlinder Anthrop. Gesellschaft. Ap. 16, 1881.

5 The Native 'Tribes of Central Australia.

23—2

356

THE SOFT TISSUES

[SECT. C

feeble development of the hair, but while the Negrito races of
Asia conform to this rule, exceptions occur among the dwarf
tribes of Central Africa, which in this respect provide the type
of gnome familiar in legend and folk-lore1. The so-called hairy
men from time to time exhibited in various parts of the world
(well-known examples are of Russian and of Burmese origin
respectively) are to be regarded as having retained an embryonic
condition : in such instances the lanugo is supposed to be per-
sistent and fully developed, and the tendency to inheritance of
the character is strongly marked. As regards records of hairless
men, a word of warning must be given as to the acceptance of
reports of explorers or travellers before the exclusion of the
possibility of epilation, or artificial removal of hair has been
considered. The practice is widely spread, and well authenticated
as in vogue among certain of the natives of Tierra del Fuego
(probably the Yahgans; cf. Darwin’s Journal).

Other characters of the hair than its abundance and distribu-
tion now claim attention. As a rule the hair is longest where
it is most plentiful. In some races the hair of the head com-
pensates as it were, by its exuberant growth, for its poverty of
development elsewhere. The extraordinary length of the hair
of the head in both sexes among certain Indian tribes of North
America is an example in point. The form of the hair finally
remains to be mentioned. Speaking generally, the varieties
usually recognised are, (1) straight or wavy, (2) woolly; and so
distinct are these types that they have been used as morphological
tests in the classification of the Hominidae. In illustration of
this application no better example can be adduced than Huxley’s
classification2, in explanation of which the author remarks that
“ In attempting to classify these persistent modifications (or stocks
of mankind) after the manner of naturalists, the first circumstance
that attracts one’s attention is the broad contrast between the
people with straight and wavy hair and those with crisp, woolly,
or tufted hair. Bory de St Vincent, noting this fundamental
distinction, divided mankind accordingly into the two primary
groups of Leiotrichi and Ulotrichi — terms which are open to
criticism, but which I adopt in the accompanying table, because

1 Sir H. H. Johnston, The Uganda Protectorate. Lanugo-liko down covers the
bodies of the Uganda dwarfs. 2 Man’s Place in Nature, edit. 1894, p. 235.

CHAP. XIV]

THE SOFT TISSUES

357

they have been used. ...Under eac
columns, one for the Brachy-cephali
or short heads, and one for the
Dolicho-cephali, or long heads.
Again each column is subdivided
transversely into four compart-
ments. . the latter corresponding
to different shades of colour of
the skin. That part of Huxley’s
classification with which we are
here concerned may be thus re-
presented.

Leiotrichi Ulotrichi

Dolicho- B lachy- Dolicho- Brachy-
cephali cephali cephali cephali

Leucous
Leucome-
lanous
Xanthome-
lanous
Melanous

Here then we see the form of
the hair used in the first rank of
morphological criteria1.

Since Huxley adopted Bory cle
St Vincent’s classification, a fur-
ther division of the varieties of
hair has been suggested and the
three following groups are now
recognised.

(a) Straight.

(b) Wavy.

But the morphological differ-
ences in the hair go beyond these
superficial appearances : for with
the most curly or frizzled varieties
is associated a peculiarity of im-

of these divisions are two

Fig. 216. Bush-woman of South
Africa. The characteristic features of
the hair of the head, and the accumu-
lation of gluteal fat (steatopygia) are
evident in this individual.

1 It has been displaced in later classifications, largely in view of the prominence
given in these to brain development as evinced by cranial characters.

358

THE SOFT TISSUES

[SECT. C

plantation most evident in the hair of the head ; it consists in the
segregation of the hair into groups or islets, separated by bald
areas : the appearance is described as “ pepper-corn,” the hair seem-
ing to be attached in small discrete groups, each group containing a
number of tightly coiled hairs in the form of a ringlet : the best
examples occur among the aboriginal races of Africa, among
which, and especially in the Bush race, the character has reached
the acme of development.

Again, the form of the hair, as seen when transverse sections
are viewed microscopically, provides an important means of dis-
tinction. While such sections, if taken from near the free end of
the hair, are in almost every instance circular in contour, this
feature is only retained throughout the length of the shaft by
hair which is macroscopically straight or lank : in the wavy,
and to a still greater extent in the curly, varieties of hair,
the circle is replaced by a contour of elliptical proportions.
The more frizzly and tightly coiled the hair, the flatter will be
the ellipse, and the comparison has been justly instituted with
a wood-shaving, with which such hairs agree in curliness and
in flatness of section.

Micrometric measurements provide a means for determining
an index of the section, from the formula :

breadth of the section x 100
m 6X — length of the section

and the numerical value of this index has been found to vary
between 28 and 1001, the lowest figure being provided by the
curly hair of an Oceanic negro (Papuan), and the highest by the
lank and straight hair of Mongolians. The form of the hair (in
transverse section) of a (negrito) Semang of the Malay Peninsula
is represented in Fig. 217 : it is to be noted particularly, that in
even curly hair the form of the section near the free end of the
hair tends to reproduce that of a circle, though nearer the root this
circle is replaced by an ellipse.

In association with this feature of flatness of the hair-shaft is
found a peculiarity of the hair follicle, for such hairs are not
implanted in the skin in a direction so nearly vertical to the

1 Pruner-Bey, Mini, cle la Soc. d’A. de Paris, t. n. p. 78, t. nr. p. 1.

CHAP. XIV]

THE SOFT TISSUES

359

surface as ai’e wavy and straight hairs : but, as was pointed out
by Professor Charles Stewart of the Royal College of Surgeons,
the frizzly hairs emerge very obliquely to the surface, and
in a section of the skin the hair follicle is found to be strongly
curved : the curvature is already present in the hair follicles of
the scalp of the negro foetus at 5 months1. Within the concavity
of the curve is an extensive sebaceous gland, whose situation in
relation («.) to the hair and ( b ) to the erector pili muscle, suggested
to Thomson1 that the hair follicle may have become bent round
the mass of the gland under the strain exerted by the smooth
muscle-fibres when in action. This view has much to recommend
it, and in default of a more reasonable hypothesis is recognised
as holding the field.

The pigment of hair is similar to the pigment of the skin,
which has been already commented upon. In sections, the pig-
ment appears aggregated (a) in the central portion or medulla of
the hair, though Kolliker ( Handbucli der Geivebelehre, 1889, p. 228)
points out that air bubbles in this situation may simulate pigment-
cells ; and ( b ) peripherally ; with
(Cf. Fig. 217.)

The curious phenomenon of the
hair turning white in aged negroes,
while the general colour of the skin
is unaltered, still awaits explana-
tion, though Thomson1 has at-
tempted this, on the basis of his
theory of the direction of growth of
the intermediate layers (strata luci-
dum and granulosum) of the skin.

We have seen that a general
review of the characters of the hair
shews that three principal forms
are recognisable: the straightest
variety, with a straight follicle and
circular form in section is found
to be associated with the slightly
pigmented skins of yellow races

1 A. Thomson, Knowledge, Ap. 1899.

a clearer intermediate zone.

Index
55-2

Index
58-9

fr'i.ti'Z.

Fig. 217. Two sections of scalp
hairs of a (negrito) Semaug from the
Malay Peninsula. (Skeat Exped.;
Mus. Anat. Cant.)

360

THE SOFT TISSUES

[SECT. C

whose general status is intermediate between the extremes of the
white and black races. The white races present all forms of hair,
save the extreme varieties of the frizzly type, and in general,
frizzly or very curly hair is usually a mark of negro (or negrito)
admixture or descent : in the negro, the hair is scanty, the beard
minimal, the hair peculiarly distributed on the head, the section a
flattened ellipse, and the follicle strongly curved.

With regard to colour, the extreme types (as regards form) of
hair nevertheless agree in being black, the curly varieties of hair
being almost invariably of this shade : the intermediate varieties
may in the white races present the various shades of colour
familiar in Europeans, but the wavy hair of the Veddahs of
Ceylon, of certain aboriginal tribes of Madras, of Sakais of the
Malay Peninsula, and of aboriginal natives of Australia resembles
the curly hair of negro races in being black. The pygmy races of
Central Africa are characterized by the dull grey or greenish-
brown colour of the scalp hair: the frontal hair is lighter in tint
than that further back1.

The cutaneous glands and subcutaneous tissues. The large
size of the sebaceous glands in the Bush race and negro races
of Africa has been incidentally mentioned. With regard to the
mammary glands, the chief points to notice refer to their form,
and the maintenance of this after pregnancy. Floss- has classified
the external form of the breast as represented by various human
races, but the classification is of little value from the point of
view of comparative morphology8.

The greater size of the mammilla may be claimed as a simian
character of the negro races. But it seems probable that the
characters of the breasts are the outcome of modifying influences
of secondary importance. This brief note may be terminated with
a reference to that character of men of certain South African
negro (Zulu and other allied) tribes which has been described as
Lobengulism. This development of the subcutaneous tissues is
very conspicuous in the natives referred to, but there is no

1 Sir H. H. Johnston, The Uganda Protectorate , Vol. n. 2 * Das Weib.

3 Baelz, Z. far Ethn. Band 33, s. 219, discusses the relation of the so-called

“ Supra-mamma ” to vestigial supernumerary mammae.

THE SOFT TISSUES

361

CHAP. XIV]

information accessible to shew exactly which tissue the hyper-
trophy in question has affected.

The steatopygia or gluteal hypertrophy of African negro races
reaches its maximum in the (yellow) Bush-woman. In this case
the gluteal mass (cf. Fig. 216) is found to consist of fat and
connective tissue overlying the M. gluteus maximus. While the
phenomenon may be due to secondary sexual modifications, one
notes a certain degree of the same character even in the male
sex, viz. in Bush-men, and the suggestion that this gluteal develop-
ment may be analogous to the hump of the camel, the gluteal
fat of certain sheep, the caudal fat of certain Galagos (Lemuridae),
and of certain desert-inhabiting Mammals (Marsupials) of Central
Australia, does not seem altogether unworthy of investigation,
especially when it is remarked that the Bush pygmies inhabit
desert-wastes like the Karoo, which prove their only refuge against
stronger and larger neighbours.

The Eyes. Three main divisions of eye-colour can be con-
veniently adopted, viz. light, intermediate, and dark.

Light-coloured eyes include blue and grey eyes.

The intermediate group includes green, greenish-grey, hazel,
and the lightest brown eyes.

Dark eyes are brown, of shades other than the very lightest.

The latter eyes are most similar to those of the Simiidae, and
indeed the Anthropoidea in general ; and among the human races
very dark eyes are accompanied by an indication (sometimes in the
form of isolated patches) of the pigmentation of the sclerotic so
common in the lower Primates, and in the lower Mammalia.

The eyes, like the hair, of the human child tend to become
darker with progress in age.

With regard to the distribution of eye-colour among the
various human races, eyes of the first class (blue and grey) occur
among the white races: the same remark holds good for the second
class with the possible exception that some yellow races are said
to possess very light brown eyes1. But the great majority of the
yellow races and all the negro races come into the third class,

1 Denilcer, The Races of Man , p. 49.

THE SOFT TISSUES

362

[sect, c

having eyes of a dark brown shade of colour. The white races
also come into this category.

From the foregoing remarks it appears that the colour of the
iris is not a very satisfactory means of classification, and in fact it
is employed rather as an accessory than as a primary criterion.

But in connection with the eyes certain other morphological
characters may he mentioned. Bruner Bey1 suggests' that the
ocular globe in the negro races is larger than in the white races :
the plica semilunaris is said to be less vestigial in the black races;
Giacomini- found remnants of cartilage in this region in a Bush
native of S. Africa, and also an accumulation of glandular cells
similar to those observed by him in Cercopithecidae, and identified
with the Harderian gland of lower mammals. Further, the circular
ciliary muscle is largely developed, suggesting slight hyperme-
tropia, which indeed from the observations of Callan3 seems to be
normal in negro races. Another point in this connection is the
effect of the form of the orbit on that of the ocular globe and
consequently on vision. If the orbit is flattened, i.e. micro-semic
(chamae-conchic in the terminology of German writers), the vertical
diameter of the eyeball will be small, and probably its sagittal
diameter will in compensation be relatively long. An eyeball
with such proportions is liable to be myopic, though it is stated
that the rarity of myopia among the Finns and Esthonians is
detrimental to this theory4.

The “ Mongolian ” eye is characterized by the narrowness, and
by the obliquity of the rictus oculi, as well as by the cutaneous fold
which crosses the inner angle of the eye, obscuring the caruncula
lacrymalis8.

This cutaneous fold (cf. Fig. 218) is associated with imperfect
development of the nasal bones in the white races, and this is not

1 Quoted by Harny and Hovelacque, Precis d’A. p. 309.

2 Annotazioni sopra Vanatomia del negro, 1878, 1882, 1884.

3 American Journal, Ap. 1875.

4 Cf. Swanzy, Handbook of Ophthalmic Surgery, and reference in Chapter xi.
page 268.

8 This skin-fold is to be clearly distinguished from the plica semilunaris, which
is much more deeply situated. A recent contribution to the extensive literature on
this subject was made by Baelz, Z. fur Ethn. Band 33, p. 187. I he plica
semilunaris is frequent, and contributes to the Mongolian appearance of the eye, in
certain idiot children (cf. inter alia, Ireland, Mental Affections in Children, p. 57).

THE SOFT TISSUES

363

CHAP. XIV]

infrequent in European children, disappearing as
in prominence. It is thus probable that the
permanently smaller nasal bones of the yellow
races, in which this fold is present (many
Chinese are exceptions, as also most of the
American races) is responsible for the con-
dition, though it is noteworthy that the
negro races in which the nasal bones are
flatter and smaller than in Mongolians are
not thus characterized : but Testut* 1 states
that the fold occurs sporadically among the
Hottentots.

The choanoides muscle or M. retractor
oculi is constant in the Cercopithecidae and
lower Mammals. Chudzinski has recorded
it in negroes; this occurrence may be claimed
as evidence of the lowlier status of the
pigmented races.

the nasal bones gain

Th.

Pig. 218. Diagrams
of the appearance of the
eye. (A) normal, (B)
epicanthus, the epican-
thic fold (P) giving rise
to the appearance known
as that of the Mongolian
eye.

The Ears. The racial aspect of the anthropology of the
external ear still awaits investigations capable of leading to
definite general conclusions. In the Simiidae and Hominidae
alike the external ear is degenerate as compared with its condition
in the lower Primates, still more in the lower Eutheria'2. Within
the Simiidae, variations in form occur, the Orang-utan and Gorilla
having small ears, the Chimpanzee differing from both in the
possession of large ears. Even among Chimpanzees a considerable
degree of variation is possible, and the size and proportions of the
ear have been used as a means of differentiating several varieties
of this animal. Among the Simiidae the external ear is in general
form very similar to that of the Hominidae : apart from the
actual size, the proportions (as expressed by an aural index
_ breadth x 100

height

the generalized Mammal in the possession of a wider auricle, with
a correspondingly higher index. Two descriptive points remain

1 Anatomie humaine, tome in. p. 228.

2 Chudzinski (Les muscles peauciers) remarks that the external ear is usually
degenerate in animals possessing a well-developed clavicle.

j shew that the Simiidae approach rather nearer

364

THE SOFT TISSUES

[SECT. C

for notice, (a) The margin of the helix is, in the Simiidae, thin
and it is not rolled over so completely as is normal in the Homi-
nidae. In the latter, then, a thin and unrolled helical margin is
a simian feature, (b) The lobule is by some said to be non-existent
in the Simiidae : but it is not always absent, though even when it
is present it is not detached from the side of the head as in the
perfect human form. A “ soldered ” lobe in the Hominidae is
therefore to be regarded as a simian character.

Within the Hominidae it is to be noticed that in general the
ear is larger and projects further from the head in man than in
woman : a measure of its projection was devised by Frigerio (the
auriculo-temporal angle1). The angle at which the auricle is set
on the head is included by the base line of the head (from the
inferior orbital margin, to the superior margin of the external
auditory meatus), and the long axis of the auricle: marked obliquity
is observable when this angle exceeds 112° (Schwalbe1). But
no general statement can bo made on this subject, so far as the
influences of age, sex, or race are concerned. Long after maturity
a recrudescence of growth is noticed in the auricle, which increases
in size in the later years of life.

With regard to racial differences in the form of the ear we
may notice that Rauber2 3 states that the aural index ( v . infra ) is
least in the yellow races, intermediate in the white, and greatest
(i.e. most Therian) in the black races. Herein Rauber is probably
following Topinard a, who makes a similar statement with regard
to the yellow races, but it is to be noted that a single example
only is adduced.

Topinard’s data are here appended : from these it appears that
the aural index possesses a zoological as well as an anthropological
significance.

, . . breadth of auricle x 100

Aural index = . ■ t- — j. :

height of auricle

1 Cf. Schwalbe, Archiv fur Psychiatric, 1895.

2 Anatomic dies Menschen, Leipzig, 1897, Band n. p. 774.

3 til. cl' A. gin. p. 1004.

CHAP. XIV] THE SOFT TISSUES 365

No. of

observations

Hominidae

Index

1 ...

Mongol

... 51-4

8 ...

Whites (average)

... 54

13 ...

Negroes „

... 61

8 ...

Melanesian Negroes (average)

... 59-5

3 ...

Polynesians (average)

... 60

Simiidae

2 ...

Gorillas (average)

... 694

3 ...

Chimpanzees (average)

... 71-1

1 ...

Orang-utans (average)

... 85-1

Cercopithecidae

1 ...

Cynocephalus

... 62-

1 ...

Cebus

... 81-

1 ...

Macacus

... 88-

1 ...

Cei’copithecus

... 90-5

The writer has made several observations1 upon specimens in

1 Aural Indices

Eight ear

Left ear

Hominidae.

Kroo negro S

57-3

52-8

Australian aboriginal <S

44-1

43-2

n it 7

50-7

54-8

European child (7 yrs.)

62-2

65-9

European human foetus :

(1) Early fifth month

78-9 (?)

66-6

(2) ii it it

72-2 (?)

55-5

(3) „ sixth „

50-8

(4) „ ninth „

80-6 (?)

83-3 (?)

Simiidae.

Gorilla S

70-6

Chimpanzee

72-7

83 (?)

77-2

78-3

Cercopithecidae.

Macacus monkey (1)

96-8

93-7

„ (2)

87-1 (?)

(3)

77-1

77-7

„ (4)

65-7

78-7

„ (5)

93-3

84-8

Cercopithecus monkey

85-1

Cebidae.

Cebus monkey

81-8

78-7

Chrysothrix sciureus

79-1

83-3

Lemuridae.

Lemur varius

74-2

366

THE SOFT TISSUES

[SECT. C

the Cambridge Museum, from which the general indications corro-
borate the conclusions of Topinard. But the variability of the
character is marked, for the aboriginal of Australia provides an
index numerically lower than that of the Mongol in Topinard’s
list, while a human foetus (European) at the ninth month is quite
out of place.

But Topinard further mentions that in point of size the auricle
is greatest in Melanesian negroes, then in Polynesians, least in the
yellow races, the length of the ear providing a similar seriation.
The African negroes however, to judge from my own observations,
frequently possess a small and almost delicately-formed external ear.

Absence of the lobule is said by Topinard (op. tit. v. p. 364,
supra) to occur with unusual frequency among the Berbers of
North Africa and among the Cagots of the Pyrenees.

While the requisite evidence for establishing morphological
generalisations of wide application is thus scanty, it is quite
otherwise as regards the more limited range of the white races ;
much labour has been expended in observing ear-forms, more
particularly in relation to social environment, and the investigation
of the suggested “criminal-type” of external ear. So for instance
Gradenigo (quoted by Schwalbe1) submits that the following
features characterise criminals and lunatics.

1. Great projection of the auricle from the side of the head.
(It may be noted that this is not a character of the black races,
nor of the Gorilla or Orang-utan, though very conspicuous in
the Chimpanzee. W.L.H.D.)

2. Lack of inrolling of the helix.

3. Prominence of the anti-helix.

4. Prolongation of the lobule on to the cheek.

5. Presence of an elongated depression on the lobule (viz. the
scapha continuous with the sulcus supralobularis, or lobe travers4e
of Bertillon).

But even so, these matters are far from final settlement, and
will consequently be passed over without further comment, a
list of some of the more important papers on the subject being
appended1.

1 Waida, Archivfilr Psychiatric, 1899, xxxii. ; C. U. Lib. xxvn. 54, 132. Schwalbe,
A. far Psych. Vol. xxvii. 1895; Gradenigo, A. fur Ohren-heilhunde, xxx. 1890, s. 230;

THE SOFT TISSUES

367

CHAP. XIV]

The Nose. The nose is a distinctive feature of the human
physiognomy, for although Hylobates (Simiidae) has a quite recog-
nisable nose this is far from having attained the prominence of
the human organ. Among the Cercopithecidae, certain monkeys,
such as the Nasalis and Roxellana apes, Jiave well-developed noses,
and in old male Nasalis monkeys the organ may be grotesquely
exaggerated in size. (Cf. Fig. 27.)

But even here the parallel is inexact, for the nose in Nasalis
larvatus is a mere mass of connective tissue, which lacks the
comparatively elaborate skeleton of the human nose.

Among the Hominidae, the full size of the nose is attained late in
the post-natal period, and indeed progress in growth coincides with
the recrudescence of facial development noticed at puberty. The
nose of the infant is flat and wide ; these characters are retained
throughout life in the yellow and in the black races, and to some
extent in females in the white races. The nose thus attains its
greatest development among male members of the white races.
With regard to proportions, the infantile features are, as previously
mentioned, flatness, with considerable relative breadth as measured
across the widest portion of the nose. A nasal index for the
external nose has been devised, whereby the breadth and height
of the nose are compared, just as for the nasal index in the skull,
a comparison of the corresponding dimensions of the apertura
pyriformis nasi is instituted. In the living subject (cf. Anthro-
pometry, Chapter XIII. p. 344)1 the nasal index is derived from the

„ . . . nasal breadth

formula, index = -r— x 100.

nasal length

But the numerical value of the index is very different in the
skull and on the face: for the latter the limits taken are 70 and 85.
Up to 70 then, leptorrhine is the term applied; from 70 to 85
inclusive, mesorrhine ; and over 85, platyrrhine.

Z. far Ohren-h. xxn. 1892, s. 179; A. fur Ohren-h. xxxn. and xxxm. Vali, A. filr
Ohren-h. xxxiv. 1893. Daa e,Z. fur Ohren-h. xxiv. 1893, s. 288. Warda, Degenerate
Ear-forms .. .Neurol. Centralblatt. 17, 1898, s. 526. Ganter, Archiv filr Psych, xxxvm.
Heft 3, s. 998, found that 55 °/0 of a series of lunatics presented aural anomalies.

1 The maximum breadth is simple to measure, but the nasal height is not
so easily determined ; the nasal spine is not difficult to find, but the situation of
the nasion is often obscure; Topinard explains that it corresponds in level with
the lower of two transverse grooves commonly found traversing the nose about the
level of the eyebrows, and this guidance is the best available at present.

368

THE SOFT TISSUES

[SECT. C

Deniker1 gives an exhaustive list of these indices, which range
from 604 in the white races (Armenians), to 107-9 in West African
negroes. The same writer (op. cit. p. 80) notes that noses may in
profile provide the following appearances :

(1) Straight or slightly sinuous (white races and certain
yellow races).

(2) Concave : typically seen in some aborigines of Australia :
also in the Bush natives, in Lapps and Finns.

(3) Convex and sometimes arched: white races (Jews) and
American aborigines.

The characters of the nose in infants of white race and the
resemblance borne to the nose in adults of other races have
previously been described (Chapter vie).

The Mouth. The conformation of the lips affords a means of
distinguishing various human races, for the lips are finest and least
prominent in the white races, coarsest, projected and everted in the
negro races (especially African negroes), the yellow races occupying
in this respect an intermediate position.

The Teeth. A general survey of the characters of the teeth is
provided in Chapter vi. (q.v.), and in the present connection
comparison will be confined within the limits of the Hominidae2 3.
The possession of an ample palate and large well-formed teeth by
the black races is a matter of common knowledge (as is the fact
that in the crania of the prehistoric inhabitants of Europe the size
and quality of the teeth, were superior to those at present obtaining
in the same geographical area). It is therefore impossible to overlook
the inference that reduction in the size of the teeth is at least
attendant (if not dependent) upon the acquisition of higher
grades of civilisation and directly upon diet and the preparation
of food.

As a means of comparison, the dental index devised by Flower2

1 Races of Man, Appendix hi.

2 Ethnic deformation of the teeth must be mentioned here. The nature of the
deformation, which usually takes the form of filing, or violently extracting one or
more teeth, is as a rule easily recognisable. Crania from New Guinea in the
Cambridge University Collection bear the teeth of pigs, substituted posthumously
for the original teeth.

3 Journ. Anthr. Instit. 1885.

THE SOFT TISSUES

369

CHAP. XIV]

is noteworthy, and it will be explained in the section dealing with
the molar teeth.

Turning again to the dental variations among the Hominidae,
and particularly to the incisor teeth, we may notice the records* 1 of
enormous teeth of this description in the Admiralty Islanders, who
are of Melanesian or Oceanic-negro stock. Such teeth are commonly
spatulate, i.e. their lateral margins are divergent towards the free
extremity. The condition is well shewn in the incisor teeth of an
aboriginal native of Australia in the University Museum (v. Fig. 107)
and it has been remarked as a feature of the incisor teeth of negroes
by Regnault ( Soc . de Biologie, 1893). The spatulate incisor is
typical of Nesopithecus. (Cf. Chapter xvn.)

An interesting point regarding the incisor teeth was brought
out by Turner2, who remarked that among the prognathous
aboriginal natives of Australia the upper incisor teeth do not
overlap those of the mandible in front when the jaws are closed,
but that the teeth of the upper and lower series bite edge to edge.
A similar observation had long before been made relatively to the
crania of Greenlanders and to crania of prehistoric date found in
Denmark3. The condition is not constant in any of the groups
mentioned, but its significance is undoubtedly great. For it
indicates that the reduction of the mandible is not so great
(in such individuals as present the character) as in instances of
overlap. The condition is clearly illustrated by Turner in the
memoir referred to.

The tendency to suppression of the lateral incisors in the white
races has been already mentioned. This tendency, it may be
remarked, is more pronounced in the upper jaw than in the
mandible.

The canine teeth present few striking anomalies beyond greater
development in size in the megadont Hominidae.

The pre-molar and molar teeth are measured in the computation
of Flower’s dental index, as derived from the formula :

Index

_ combined length of crowns of pre-molar and molar teeth x 100

basi-nasal length ;

1 Cf. Miklucho-Maclay. Zeits.filr Etlin. Bd. vui. 1876, PI. xxvi.

2 J. Ariat. and Pkys. Yol. xxv. 3 Cf. Lubbock, Nat. Hist. Review , 1860.

D. M.

370

THE SOFT TISSUES

[SECT. C

and upon the numerical values of this index a classification has
been based in the following way :

Crania in which the index falls short of 42, are microdont.

Crania in which the index is from 42 to 44 (inclusive), are
mesodont.

Crania in which the index is above 44, are megadont ;
and the illustrations following, which are taken from Flower’s
memoir, afford a good demonstration of the greater size of the
teeth in the negro-races.

Microdont Hominidae : index below 42.

Europeans, prehistoric Egyptians, Polynesians, low-caste
natives of Central and Southern India.

Mesodont Hominidae : index 42 to 44 (inclusive).

Chinese, American Indians, Malays, African negroes : in the
latter the value of the basi-nasal length is numerically very great,
and hence their appearance in this class.

Megadont Hominidae : index above 44.

Melanesians, Andamanese, Australian and Tasmanian abo-
rigines. For the teeth of aborigines of Australia in the University
Museum an average index of 45‘2 was obtained. Female skulls
provide an even higher figure (49'25).

Finally the following data are of comparative value :

Gorilla (average index for both sexes) 54T
Chimpanzee (average index for both sexes) 47-9
Orang-utan (average index for both sexes) 55-2
Hylobates: 1 example 41 ‘7.

(The latter is thus microdont.)

The number of cusps carried by the several teeth of the molar
series has been counted in a great many instances, and the chief
contributors to these statistics are Zuckerkandl, Rose, Topinard, and
Tomes1. Zuckerkandl examined 542 crania; Rose 1241 maxillae,
and 828 mandibles ; Topinard, 595 crania ; while Tomes does not
mention the number at his disposal.

The general conclusions of the two first-named observers are
in agreement, and to the following effect.

1 Zuckerkandl, SchefE’s Handbuch der- Zahn-heilkundc, Bd. I. Rose, Anat. Anz.
vii. Topinard, L’ Anthropologic, 1892. Tomes, Dental Anatomy , 1898.

THE SOFT TISSUES

371

CHAP. XIV]

The normal number of cusps is four for upper molar teeth, and
five for lower molar teeth.

The same general pattern obtains, both in European and
non-European Hominidae, in both of whom
the third molar tooth of the upper series
has undergone more reduction than any
other tooth. Such reduction is more active
in European than in non-European Homi-
nidae, and chiefly affects that cusp which
has most lately appeared, viz. the postero-
internal cusp (cf. Fig. 219. PI) so that a
tendency to trituberculism is in progress.

Tomes in turn gives a general assent
to the conclusions of Topinard, who un-
consciously confirms the foregoing earlier
observations, and provides some statements
of detail as follows :

The first upper molar tooth appears to be subject to but little
variation in all Hominidae.

The second upper molar tooth bears four cusps in only 58 °/o of
highly civilised races, and in 80 °/o of primitive races, such as the
Malays and Melanesians.

The third upper molar tooth bears four cusps in only 37 °/o
(of all races) : and in 6 % of all Hominidae it is quite irregular in
form.

Of the lower molar teeth, the first bears five cusps in 77 °/0 only,
of highly-civilised races, but in Polynesians five cusps are the rule
in 91 % of examples. This is thus more variable than the first
upper tooth.

The second molar tooth is very subject to variation; five cusps
are found in only 33°/o to 37 °/0, even in primitive races. Four
cusps (and not five, as Zuckerkandl and Rose state) are apparently
the normal number for this tooth.

The third molar tooth is also variable ; four cusps are rare, and
three are found in as much as 04 °/0 of highly-civilised races. Three
cusps may thus be considered the normal number in these races.
Even in the primitive races, such as the Melanesians, three cusps
occur in 28 °/0 of cases.

Fig. 219. Diagram of a
molar tooth of the right
upper series. AE, antero-
external eusp. AI, antero-
internal cusp. PE, postero-
external cusp. PI, postero-
internal cusp, x, region in
which small accessory cusps
appear.

24—2

372

THE SOFT TISSUES

[SECT. C

On the whole, then, the upper teeth tend to become tricuspid,
and the last tooth is degenerate to the verge of suppression. The
lower teeth are in transition from a five-cusped pattern to a four-
cusped type, the cusps being separated by a crucial fissure marking
the dental crown.

There remains for notice a curious condition of the molar teeth
most frequently observed in natives of the Chatham Islands
(Mori-ori) and in Maories; also, but less commonly in Eskimo.
The molar teeth are dislocated and inflected inwards, so that
instead of the normal upper surface, the labial side of the crown
comes into use : the significance and causation of the condition are
quite obscure, but it would appear to be related to the nature of
the diet of the natives among whom it obtains.

The Tongue. The tongue of the black races might be expected
to prove larger, thicker, and less pointed than that of white men,
in correspondence with the long hypsiloid palates found in the
skulls of those races, but little or no information is as yet accessible
on this point. A similar lacuna of observation exists with regard
to the number and disposition of the circumvallate papillae.
Humphry1 describes these in a Chimpanzee as distributed along
the median line of the tongue ; but no comparative (human)
observations are as yet accessible to the writer. With regard
to the lingual musculature, Serres, quoted by Hovelacque and
Hamy2, states that the anterior fibres of the M. styloglossus are
but feebly developed in negroes.

The Intestines. Chudzinski3 discusses the relation of the
length of the intestines to the stature in the white and black
races respectively, and concludes that the proportion is less in the
latter than in the former; for in negroes the intestine seems to
measure from 4T4 to 6'11 times the amount of the stature, while
in the white races the proportions cited by various authors vary
from 3 — 84. If the intestinal length be compared, not with the
stature, but with the length of the vertebral column, the proportion

1 Joiirn. of A. and P. Vol. v. Old Series.

5 Precis d’Anthr. p. 301.

3 Revue d’Anthr. 1887, p. 276. Chudzinski’s records contain references to the
proportionate length of the intestine in an Annamese, a Peruvian, and an Arab.

4 The lower figure (3) is quoted by one anatomist (Cruvoilhier) only.

CHAP. XIV]

THE SOFT TISSUES

373

in the negroes observed by Chudzinski agrees with that recorded
in an Orang-utan by the same observer (about 10’28). But no
records of this proportion are provided for the white races.

A comparison of the lengths of the small and large intestine
respectively, indicates that the relative shortness of the intestine
in negroes as compared with white men, is determined by the
shortness of the small intestine, for the colon would appear to be
absolutely and relatively longer in the black races. It may be
noted that Chudzinski’s series is quite a small one (of nine
individuals).

Turner1 records a double rectal mesentery in a male negro.

Flower and Murie2 state that in a young Bush-woinan the small
intestine measured 15 ft., the large intestine 4 ft. (2-6 to 1), a pro-
portion which is ultra-negroid and distinctly simian.

In the post-mortem room of the Greenwich Seamen’s Hospital
I saw the caecum of a mulatto ; no unusual abnormality was present :
the vermiform appendix was of moderate length and projected into
the pelvic cavity.

Huntington3 figures (op. cit. Nos. 519, 522, 526) three caeca of
Eskimo natives of Smith’s Sound. One of these (op. cit. Fig. 522)
is described as similar in conformation to the caecum of a Gorilla
(op. cit. Fig. 457) represented in the same work. The similarity is
particularly noticeable in the position and form of the vermiform
appendix. But the other Eskimo caeca do not present the same
conformation, and the caecum of the Gorilla referred to, differs from
that described in an earlier Chapter (iv.) of the present work.
Here, again, the necessity for a statistical enquiry bearing upon
both Simiidae and Hominidae is apparent.

The Liver. Chudzinski4 states that in his series of negroes
the average size and weight of the liver was less than the average
in white men. At Cambridge two livers of negroes are available
for observation. In one of these no important departure from the
normal type of liver in the white races could be observed : and in
particular no exceptional fissures suggesting division of the right
or left lobes were noticed. The second liver would be considered

1 Journ. A. and P. xxxi. p. 624. 2 Journ. A. and P. Yol. i.

3 The Anatomy of the. Human Peritoneum and Abdominal Cavity.

4 Revue d’A. loc. cit.

374

THE SOFT TISSUES

[SECT. C

quite anomalous in a white man. The most striking feature is
the extension and large size of the left lobe. But where statistics
are so scanty no stress can be laid on this record. The liver of
the Annamese recorded by Chudzinski is smaller than that of the
average white man. In the Bush-woman dissected by Flower1, the
liver weighed 54'75 oz. and measured 10 x 7 in. (about 250 x 175 mm.,
which is distinctly small). The lobar divisions corresponded to
those usually described, and the caudate lobe, though rudimentary,
was distinguishable (a simian feature), though not unusually ex-
tensive. The gall-bladder was small and cylindrical (i.e. infantile).

The Spleen. Chudzinski2 states that while the volume of the
spleen was on the average less in his negro series than in the
white races, yet no appreciable difference existed in point of weight.
In the Bush-woman dissected by Flower the spleen was pointed at
either extremity.

A very generalized type of human liver is described and
figured by Parsons3. The specimen is from the post-mortem
room at St Thomas’s Hospital.

The Pancreas. In the Bush-woman dissected by Flower no
anomaly was observed in the pancreas.

The Larynx. The laryngeal sacculi of the larger Simiidae are
not normally seen in the Hominidae, but among the latter a vestige
of the former presence of saccules is said to be shewn in the larynx
of the negro, inasmuch as the ventricles are here much more
extensive and capacious than in the white man. In a negro
dissected at Cambridge the laryngeal ventricles were quite similar
in this respect to those normal in the white races : it must not be
overlooked, moreover, that in the latter, the laryngeal saccules
of Simiidae are occasionally reproduced ; to a case of this kind,
recently met with (cf. Fig. 160) in the Anatomy School at Athens
and reported in the Anatomischer Anzeiger (1902)4, reference has
already been made (cf. Fig. 220). In the Kroo negro dissected
at Cambridge an accessory laryngeal muscle (cf. Fig. 221) was
found. The same muscle has been observed by Mr Sewell in the
larynges of human foetuses, in which it is conspicuous.

1 Journ. A. and P. Vol. i. 2 Revue d'Antli. loc. cit.

3 Proceeding <? of the Anatomical Society, February, 1904.

4 Cf. also Sclavunos, Anat. Am. Band xxiv. Nos. 19 and 20.

CHAP. XIV] THE SOFT TISSUES 375

With regard to the comparative morphology of the lungs within
the Hominidae little or nothing seems to be known at present.

Fig. 220. Fig. 221.

Fig. 220. Laryngeal Saccules iu Man. (Cf. Fig: 160 and context.)

Fig. 221. Larynx of a Kroo negro, dissected from the right side; there is an
accessory muscle, viz. an accessory M. thyro-arytenoideus. (M. thy. ar. acc.)

The Vascular System. In the vascular system, the chief
point of importance is the arrangement of the chief arterial trunks

arising from the aortic arch. The
investigations of the Committee ap-
pointed by the Anatomical Society
shew that the arrangements here
diagrammatically represented are
the commonest in white men, that
of type (1) accounting for 88'2 of
cases (cf. Fig. 222). Keith1 notes
that the forms (2) and (3) are simian,
and thrice as numerous in the black
as in the white races.

' x. 3.

/nt/s

Fig. 222. Diagrams illustrative
of the three commonest modes (in
order of frequency) of the origin of
the great arterial trunks from the
aorta in Europeans.

1 Journ.A. and P. xxix. p. 453; also Parsons, ibid. xxxv. p. 389.

376

THE SOFT TISSUES

[SECT. 0

A negro (No. 3) dissected by Turner1 presented the unusual
(white) anomaly of a right subclavian artery arising alone from the
descending aorta, below the ductus arteriosus ; this represents a
remnant of the right aortic arch (cf. Fig. 223).

Fig. 223. Anomalous origin of the right subclavian artery (B.s.) in a negro.

Fig. 224. Palmar arteries (superficial and deep arches) in the left hand of a
Kroo negro dissected at Cambridge (W.L.H.D.).

The above figure (224) represents the arrangement of the
palmar arteries in a negro dissected at Cambridge. (No. 1.
W.L.H.D.)

In the Bush-woman dissected by Flower the heart resembled
the corresponding organ in white races. The aorta gave off
three great trunks in the manner normal in white races, but
the trunks were closely approximated. The vertebral arteries

Fig. 224.

1 Journ. A. and P. xxxi.

THE SOFT TISSUES

377

CHAP. XIV]

arose from the subclavian arteries on each side. No “anomalies”
were seen in the branches of either carotid or of the limb-vessels.
At the base of the brain the left vertebral artery had a calibre
double that of the right artery.

The Lymphatic system. Reduplication of the thoracic duct
has been recorded in a negro1.

The Genito-urinary system. The kidneys. Chudzinski’s2
records shew that in his negro series the volume and weight of the
kidneys are on an average less than in the white races, while in
both groups the left kidney is larger than the right. In the
Bush-woman dissected by Flower no anomalies were seen in the
kidneys.

The Suprarenal bodies. Chudzinski’s3 series of negroes
shews that on the average the size of the suprarenal bodies is
greater in the black than in the white races, but at the same
time the weight is on the average much less in the former.

In the Bush-woman dissected by Flower no anomalies were
seen in the suprarenal bodies.

Brown-Sequard and Pruner-Bey4 state that both the suprarenal
bodies and vesiculae sem inales are larger in the black than in the
white races : they agree herein, as regards the suprarenal bodies,
with Chudzinski, but more observations are desirable before a final
conclusion can be arrived at. Similar comment applies to the
statement made by Hovelacque and Hamy5 that the bladder is
placed at a higher level in the black than in the white races : if so,
this is an example of the persistence of an infantile character in
the negro races ; it is thus intelligible in view of the other infantile
traits of the black races.

It remains to consider the external genitalia in the two sexes.

A. The Male. The relatively greater size of the penis in
negroes has long been recognised. The os penis is unknown in
Man.

1 Turner, Journ. A. and P. xiv. p. 244.

2 Revue d'A. loc. cit. '■> Revue d’A. loc. cit.

4 Bull, de la Soc. d’Anth. de Paris, 1800, p. 30.

6 PrScis d'A. p. 302.

378

THE SOFT TISSUES

[SECT. C

B. The Female. Turning to the external genitalia of women,
the relatively feeble development of the mons veneris and labia
majora in negro races and in Bush-women has been claimed, with
some justice, as a simian characteristic. The labia minora are
variable in their development in the black races, for in some
instances they would seem to be l’elatively smaller than in white
women: in the black Hamitic tribes of Abyssinia the labia minora
are said to be relatively large. The extreme of this hypertrophy
is attained in the Bush natives, and the following notes give an
account of the conformation of the generative organs of a Bush
native (young woman)1.

The external genitalia presented the very striking and charac-
teristic conformation of the females of this race, viz. the small
labia majora vulvae associated with elongated pendulous labia
minora ; the latter in this young woman were of triangular form,
the base extending anteriorly into a larger prominent prepuce
which covered a clitoris of moderate dimensions. The labia minora
thus differ from those described in the same paper (q. v.) in older
women as drawn out into a thong-like form with expanded
extremity.

These characters of the genitalia are not simian, .and consist in
an excessive development of the condition normal in the female
foetus of white races, and in women of black races. The clitoris is
said to be relatively larger in certain black races, and would thus
suggest a resemblance with some of the lower primates, especially
certain of the Lemuroidea, in which the clitoris is greatly developed.
The vagina in the black races is said to be longer than in women
of white races.

Muscular system. Materials for the study of the comparative
muscular morphology of the human races are even at the present
time very scanty, although the observations are daily increasing
in number and accessibility. Moreover at the present time no
general summary is accessible, comparing or bringing into line
the results recorded by various observers. The remarks on this
section must therefore needs be limited, not because the subject is
unimportant, but because no final account can yet be submitted.

1 Flower and Murie, Journ. A. and P. Vol. i. Also Blanchard, Bull. Soc. Zool.
France, 1883.

THE SOFT TISSUES

379

CHAP. XIV]

For the sake of convenience we shall consider the muscular
system under the two headings of “A, Muscles of Expression and
their allies ” ; “ B, The general Skeletal Musculature.”

A. Muscles of Expression and Associated Muscles. The com-
parative study of the muscles of expression has received more
attention than has been devoted to any other group of muscles1.
Nearly a century ago Sir Charles Bell wrote a work which has
become classical, on the expression of the emotions and its
anatomical basis, dealing with the anatomy of the facial muscles
of expression and with their nerve-supply.

Following this work came those of Darwin (The Expression of
the Emotions in Man and Animals), and Duchenne de Boulogne ;
the former dealing with the subject from the standpoint of evolution,
the latter taking up the relation of the nerve-supply and superficial
landmarks, as well as the pathological conditions of these structures
(e.g. facial paralysis).

Of late years numerous dissections have been made of the
muscles of expression in the Simiidae, and in various racial types
of the Hominidae. In the case of the Simiidae, the classical
work of Duvernoy on the muscular anatomy of the Gorilla2 is to be
noticed, as well as more recent publications by Deniker3 and Ruge4.

Dissections of the facial muscles among the Hominidae and in
the black races have been described by Hartmann5, Popowsky6,
Turner and other writers in the Journal of Anatomy and
Physiology7, so that on this subject a considerable amount of
information is now available. But in none of these cases is much
more than a mere record provided.

The work of Broca’s demonstrator, Th^ophile Chudzinski,
published in 1896, supplies a great want in this respect, for in it
are recorded the results of dissections on several negroes, several
examples of the yellow race, with one or two white men for

1 Camper’s work, 1789, deals principally with the physiology rather than the
anatomy of the muscles of expression.

2 Nouvelles Archives du Museum, Vol. x. » These de Paris, 1885.

* Gesichts-muskeln der Primaten. Also Morphologisches Jahrbuch, passim.

Hartmann, Anthropoid Apes. International Scientific Series.

8 Popowsky, L' Anthropologic, 1890 (also quoted by Chudzinski).

7 See especially Yols. xm. xiv. xxxi.

380

THE SOFT TISSUES

[SECT. C

comparative purposes. From this remarkable monograph we
obtain evidence of a comparative kind not otherwise so con-
cisely or exhaustively provided. For this reason we shall now
give an account of Chudzinski’s results, in so far as they bear on
the subject actually in hand.

Before entering upon this however, a few preliminary remarks
on the general conformation of the system of cutaneous muscles as
elucidated by the recent work of Parsons1, seem appropriate in this
place.

In a general review of Eutherian cutaneous musculature the
following elements are most commonly recognisable: (a) M. platysma,
( b ) M. sphincter colli, (c) M. dorso-humeralis, ( d ) M. abdomino-
humeralis.

(a) The ordinary extent of the M. platysma needs no elaborate
description in this place: in view of its nuchal distribution and
extent in primitive forms, this sheet is appealed to as the origin
of the muscles of the external ear.

(b) The M. sphincter colli (cf. Figs. 36 and 225) lies in a plane
deeper than that of the M. platysma: mesially and ventrally (an-
teriorly in erect animals) it converges to its fellow, ending in
decussation, or downward prolongation to the sternum, or even
the abdomen, occujiying in (the rodent) Bathyergus a position
analogous to that of the anomalous human M. sternalis, with which
it is identified by Parsons. (The question is however still under
discussion, and cases such as those reported by Eisler2, shew that
the M. pectoralis major may be the immediately derivative mass.
It would seem that Cunningham concurs in this view, while Parsons
has suggested that the pectoral mass may be a derivative of the
panniculus system. The community of nerve-supply supports the
latter view.)

The M. sphincter colli is absent from Cheiroptera (Bats), is very
evident in Lemuroidea (cf. Fig. 36), but above these diminishes,
till in Man only a few transverse submental fibres remain. It is
noteworthy that in the extensive researches undertaken by
Chudzinski, distinct traces of the submental transverse fibres

1 “The Panniculus carnosus and its representatives,” J. A. and P. Vol. xxxm.
1898.

2 Zeitxchrift fur Morphologic und Anthropologic, "Band in. Heft i. 1901.

CHAP. XIV]

THE SOFT TISSUES

381

were rare. Transverse fibres (muscular) certainly occurred, espe-
cially in a negro (from Pondichery), but these lay superficially to
the platysma sheet, and hence could not be claimed as remnants
of the M. sphincter colli which underlies that sheet. In animals
(like Bathyergus) in which it is well-developed, it obtains its nei’ve-
supply from the internal anterior thoracic nerve, i.e. from the inner
cord of the brachial plexus.

(c) The M. dorso-humeralis winds round the tendon of the
M. latissimus dorsi to reach the humerus, passing deeply to the
M. pectorales : it is very prominent in Cercopithecidae and lower
primate forms, including the Lemuroidea; in Man an anomalous
muscular slip, known by its German name of “ Achsel-bogen,” is
claimed as a remnant of this dorso-humeral muscular stratum.
(The “Achsel-bogen” is said to be innervated from the inner cord
of the brachial plexus.)

( d ) The abdomino-humeralis sheet is probably lost in the
sheath of the M. rectus abdominis : in rodents this sheath splits
to enclose the M. pectoralis major, on reaching the lower border
of that muscle1.

The accompanying diagram (Fig. 225) provides a plan of the
distribution of these various elements.

Fig. 225. Cutaneous musculature of a Raccoon, to shew the several constituents;
(a) M. platysma, ( b ) M. sphincter colli, (c) M. dorso-humeralis, (d) M. abdomino-
humeralis (after Parsons).

When we turn to researches carried out on the Simiidae and
Hominidae we find the several elements just enumerated in

1 This muscular stratum is represented in the perinaeal region. Lack of space
precludes further description of its representatives, but reference should be made to
researches by Kollmann and Thompson ; and especially to memoirs published by
Lartschneider (Sitz. der 1C. Akad. d. Wins in Wien. Math.-Nat. Kl. 1895,
Band. civ. pp. 150—190), and Holl. [Ancit. Hefte, 1901).

382

THE SOFT TISSUES

[SECT. C

a vestigial condition, less vestigial however in the Simiidae than
in the Hominidae ; moreover the platysma layer is the most per-
sistent of the four; and apparently it may become segmented
into several superimposed strata. Chudzinski’s researches on the
several human races led to general statements, of which a resume,
is now appended1 2.

Several layers of cutaneous muscles undoubtedly exist, and in
the “ black ” races the distinction between muscles is much less
clear than in the white races, the yellow races standing in an
intermediate position in this respect. (Chudzinski’s “ yellow races ”
must be taken to refer to Chinese and Indo-Chinese : no true
Mongols were examined : the conditions in American Indians and
a Cingalese resembled those of white races.) The muscles of the
face in the black race are also distinguished by throwing out off-
shoots which run into and blend with adjacent muscular elements.
In the black races, too, the muscles of expression are more dis-
tinctly red than in the white races.

Further general remarks apply to particular muscles, and of
these a selection will now be given :

M. frontalis : sex seems to have no value as a factor in deter-
mining variations here : the condi tion in a New Caledonian (Oceanic
negro) recalls that in the Gorilla.

M. pyramidalis : the blending of this muscle with the M. frontalis
in a Zulu woman recalls the condition in the Gorilla. (Cf. Chud-
zinski ; Bull, de la Soc. d’A. de Baris, 1886.)

M. auriculares: these, and indeed the auricle itself, are dimi-
nished pari passu with the augmentation of the clavicle and
associated freedom of the anterior limb (Chudzinski).

M. auricularis posterior (retrahens auris) : most variable in the
black races.

1 Chudzinski’s material included,

Black races : 8 male Negroes.

4 Negresses (2 Egyptian, 1 Zulu).
1 male New Caledonian.

1 Negro, native of Pondick6ry.

Yellow races : 2 Annamese.

2 Cochin-Cliinese.

1 Peruvian.

1 Arab.

White races :

THE SOFT TISSUES

383

CHAP. XIV]

M. auricularis anterior (attrahens auris) is most distinct in
the black races.

M. occipito-parotideus and M. mastoideo-parotideus occur
(anomalously) most frequently in the black races.

M. orbicularis palpebrarum in the black races is thick and
composed of interlacing fibres; it throws out radiating offshoots
into adjacent muscles, such as the M. zygomaticus major, and
the M. levator labii superioris, and also into the skin of the cheek1.
This is seen in the case of the aboriginal (male) native of Australia
(Mus. Anat. Cant. cf. Fig. 226).

M. zygomaticus major : most variable in the black races, and
often closely associated with the M. risorius. It is often connected
with the M. orbicularis palpebrarum, as is also noted by Turner
(J. A. and P. Vol. xm.), and as is seen in the dissection of the
head of an aboriginal native of Australia in the Cambridge Museum
of Anatomy. (Cf. Fig. 226.)

M. platysma in black and yellow races extends higher than
in the white races (as far as the zygoma ; Turner) : its nuchal
portion often appears detached as a M. transversus nuchae (see
also Turner, op. tit.). The great upward extent is seen in the
head of the aboriginal cf Australia in the Cambridge Museum of
Anatomy.

M. rectus sternalis has been observed in a negro by Turner.

The remainder of Chudzinski’s conclusions are best studied in
tabular form2, whence it clearly appears that the muscles of the
cutaneous system are more extensive in both black and yellow
than in white races, the order being black, yellow, white. In one

1 This condition is particularly remarked as occurring in a Papuan infant,
cf. Forster, v. infra p. 385.

2 A general survey of tabulated results shews that in respect of twenty-one
characters relative to the extent of the muscular sheet in the several races the
order runs:

Black, yellow, white, in 13 instances.

Black, white, yellow, in 1 instance.

Yellow, black, white, in 3 instances.

Yellow, white, black, in 3 „

White, yellow, black, in 1 instance.

White, black, yellow, in 0 „

21 instances.

384

THE SOFT TISSUES

[SECT. C

sense however, the segregation (in the white races) of these muscles
is not altogether a matter of degeneration, for at least it can be
claimed that it is associated with a greater degree of individual
muscular specialization.

Fig. 226. Dissection of the facial musculature of an aboriginal native of
S. Australia (Mus. Anat. Cant.).

B. The Skeletal Musculature proper. From the cutaneous
group of muscles we now pass to the skeletal group. In this
connection again the chief contributions have been made by
Chudzinski ( M dm. de la Soc. d’A. de Paris , 1898). The detailed
discussion of the results collected from the several records would
be here impossible, and moreover it belongs rather to the section
dealing with anatomical anomalies in general, for it is to these
that the attention of observers has hitherto been chiefly directed.
Such being the case, it is here proposed to submit the briefest
notices of some of the accessible accounts of such dissections as

THE SOFT TISSUES

385

CHAP. XIV]

have been made on the bodies of representatives of other races
than the white.

As a general statement, it may be remarked that in the more
prognathous “ heavy-jawed ” individuals, of whatever race, the mass
of the mandibular (temporal, masseteric, and pterygoid) muscles
is correspondingly increased.

The ensuing notes deal with the muscular anatomy of several individuals
of the black and yellow races, the records being drawn from the following
sources :

I. A Papuan infant (Forster, Anat. Anz. xxiv. No. 7, p. 183).

II. A Kroo negro (Mus. Anat. Cant. W.L.H.D.).

III. Four negroes and a native of Dacca (Turner and Bryce, Journ. A. and
P. Yols. xiii. xiv. and xxxi.).

IY. A Chinaman (Anderson Stuart, Journ. A. and P. Yol. xix.).

Y. A Bush-woman (Flower and Murie, Journ. A. and P. Vol. I.).

Chudzinski has published an exhaustive memoir on the myology of several
negroes, and other individuals of exotic provenance (such as a Peruvian and an
Indo-Chinaman) dissected by him {M4m. de la Soc. d’Anth. de Paris , 1898) ; and
Giacomini has also contributed to the subject of negro myology.

I. Papuan. Forster dissected a newly-born Papuan infant, which is in
the Anatomical Museum at Strassburg. He notes that though instances of
muscular variations of a “progressive” character were detected, yet they
were overshadowed in number by variations of the “reversionary” order.
As “progressive” variations the following examples are cited: (a) complete
independence of the M. adductor minimus : (6) the tendency to isolation of
that part of the M. flexor profundus digitorum which supplies the index finger :
(c) the complete differentiation of the thenar and hypothenar musculature of
the hand, and the corresponding elements in the foot. As “ reversionary ” in
their significance, the following anomalies (amongst others) are remarked :
(a) the lack of differentiation and the thickness of the facial muscles of
expression (v. supi-a, p. 382) : ( b ) accessory serrations of the M. serratus
anticus (magnus) : (c) unusual extent of the M. pronator quadratus : (d) presence
of a M. gluteus quartus : (e) the M. psoas minor was present, and herein
Chudzinski’s results are modified, for that observer had not been able to record
the presence of the M. psoas minor in the coloured races : (/) the M. plantaris
was quite rudimentary ; Chudzinski stated that this muscle is very constant
in the coloured races.

II. Negro. A Kroo native.

1. M. subscapularis : the humeral attachment is more extensive than
in Europeans, and is overlapped by the tendon of his M. latissimus dorsi.

2. M. latissimus dorsi : a scapular component is present : no M. latis-
simo-condyloideus is present.

D. M.

386

THE SOFT TISSUES

[SECT. C

3. M. coracho-brachialis : not subdivided as in the Simiidae.

4. M. biceps cubiti : there are no accessory heads of origin.

5. M. brachialis anticus : that part which lies externally to the inser-
tion of the M. deltoideus is very bulky. Interiorly this muscle is inseparable
from the M. triceps.

6. M. extensor ossis metacarpi pollicis : this muscle sends a tendon
to the M. abductor pollicis.

7. M. extensor primi internodii pollicis. The tendon splits into two
parts, of which one runs to the proximal phalanx of the pollex, the other
joining the tendon of the distal extensor of the thumb. The muscle arises
from the interosseous membrane as well as from the radius.

8. The M. deltoideus, supraspinatus, infraspinatus, teres minor, anco-
neus, extensores (of the wrist and digits) subscapularis, supinatores, palmaris
longus, flexores and pronatores agree with the descriptions of the correspond-
ing muscles in the white races.

15. In the larynx, an accessory thyro-arytenoid muscle was found. (Cf.
p. 374, and Fig. 221.)

III. The dissections of negroes published by Turner are three in number.

In No. 1 the following are striking features, J. A. and P. Vol. xili. p. 382 :

1. The M. platysma extends up to the zygoma and a M. transversus
nuchae is present.

2. The M. omohyoideus arises from the clavicle and not the scapula.

3. The M. constrictor pharyngis superior receives fibres from the
M. tensor palate.

4. The M. pect. minor sends an expansion from its tendon of insertion
over the shoulder-joint capsule.

5. The M. brachialis anticus is bilaminar.

6. The M. pectineus supplies a slip of muscle from its inner border to
the tendon of the M. adductor longus.

7. There is present a M. accessorius ad M. flexorem accessorium.

8. The M. peroneus is attached to the os calcis.

9. The M. lumbricalis quartus is absent.

10. The M. plantaris arises by two heads.

Negro 2 (Turner, J. A. and P. Vol. xiv. p. 244).

1. The M. zygomaticus major is blended on one side of the face with
the M. orb. palpebrarum.

2. The M. biceps cubiti has two accessory humeral heads.

3. The M. flexores digitorum sublimis and profundus are connected by
a tendon.

4. The (right) M. plantaris has no muscular elements ; it arises as two
tendons.

5. The (right) M. flexor longus hallucis sends slips to the second and
third digits (toes).

THE SOFT TISSUES

387

CHAP. XIV]

6. No M. peroneus tertius is found, but a slip to the right metatarsal
is provided by the M. ext. digitorum longus.

7. The (right) M. abductor ossis metatarsi quinti is present.

Negro 3 (Turner, J. A. and P. Vol. xxxi. p. 624).

1. The M. platysma is well developed and a M. rectus thoracis (? M. ster-
nalis) is present.

2. The M. flexor digitorum sublimis has no radial head (according to
Keith, the ulnar origin is rare in Gorilla), and its tendon to the index finger
has a fleshy belly interposed at the level of the lower third of the radius.

3. The M. semitendinosus has accessory slips.

4. The M. peroneus tertius is absent. (This muscle was absent in
Negro No. 2 also, and such absence is distinctly a simian characteristic.)

5. The M. gastrocnemius has an additional muscular origin for its
inner head.

6. The M. flexor brevis digitorum provides" no tendon to the fifth toe.

7. The M. abductor ossis metatarsi quinti is present in both feet
(this is rare in Gorilla).

Negro 4 (Bryce, J. A. and P. Yol. xxx. p. 611).

1. The M. adductor magnus shews fasciculation unusually distinctly.

2. The M. biceps femoris has an accessory fasciculus.

3. There were 34 anomalies recorded altogether : it was remarked that
in the upper limb they tend to be unilateral, but bilateral in the lower limb.

Native of Dacca in Bengal (Turner, J. A. and P.). The following con-
ditions were noted.

1. The M. sterno-mastoideus is tripartite.

2. The M. scalenus anticus originates by one slip less than in white men.

3. The M. transversalis colli arises from the transverse processes of the
upper ten thoracic vertebrae.

4. The M. latissimus dorsi arises from the four lower ribs.

5. The M. serratus magnus is attached to ten ribs on one side (R.), nine
on the other side.

6. The M. pectoralis major sends a slip to the common (coracoid)
tendon of the short head of the M. biceps and the M. coraco-brachialis.

7. The M. subclavius is absent on the left side.

8. The M. palmaris longus is absent on one side (the right).

9. The M. extensor carpi ulnaris has an accessory slip.

10. The M. pronator quadratus is bilaminar.

11. The M. extensor indicis has a muscular belly interpolated in its
tendon.

12. The M. lumbricalis quartus manus is rudimentary.

13. The M. plantaris is absent from one side (the right), cf. No. 8.

14. The M. flexor brevis digitorum provides three tendons only.

15. The M. flexor accessorius is attached to the M. flexor longus hallucis,
not to the M. flexor longus digitorum.

25—2

ao» THE SOFT TISSUES [SECT. C

IY. Chinese. The following notes form an abstract of the account of the
myology of a Chinaman: Stuart, ,1. A. and P. Vol. xix.

The abnormalities in the muscular system may be generally described as
tending towards the exuberance or redundancy of muscular tissue.

Thus the M. rect. cap. majores are large, completely covering the
M. rect. cap. miuores.

The M. rect. cap. minores consist of three separate slips.

1 he posterior belly of the M. omohyoideus is replaced by a membranous
tendon.

A communicating slip of muscular tissue replaces the tendon of the
M. digastricus.

The M. scaleni medii have accessory origins.

Several muscles in the upper extremity are provided with accessory
tendons. Thus the M. abductor pollicis has two tendons.

The tendon of the M. supinator longus is bifid, transmitting the radial

nerve.

Some of the M. lumbricalcs of the foot are absent : viz. in the right foot,
No. 3 ; in the left, Nos. 2 and 3.

V. Bush native. The dissection of a Bush native (young woman) by
Messrs Flower and Murie revealed the following disposition and characters
of the muscular system.

The facial muscles of expression shewed no striking peculiarity, and
except that there was a slightly greater tendency than in the white races,
for the several muscles to merge into one another, and thus form sheets, no
simian features were discovered.

The M. omohyoid had no posterior belly or tendinous intersection : the
anterior belly was attached to the clavicle (but this anomaly is noted by the
authors as occurring in about 3% of white individuals).

The M. cleido-occipitalis was present : this is distinctly a simian or lower
Eutherian feature (the muscle common in Carnivora and known as the M. ce-
phalo-humeralis, is allied to this muscle, of which it is regarded as the perfect
form). It occurs abnormally in the white races.

No trace of the M. latissimo-oondyloideus (dorsi-epitrochlearis) was seen.

The M. rect. cap. posticus major was partially divided : in the Canidae
it is normally double.

The M. coraco-brachialis was double.

The M. ext. pollicis minor was present and resembled its counterpart
in the white races.

The M. add. pollicis transversus had accessory origins from the fourth
metacarpal bone and (by a tendinous band) from the fifth metacarpal, but in
compensation the area of attachment to the third metacarpal was diminished.

The M. gluteus maximus was thin, and it covered the M. gluteus medius
less completely than in the white races This lack of extent is a simian
feature.

CHAP. XIV]

THE SOFT TISSUES

389

The M. peroneus tertius was present.

The M. ext. brevis digitorum supplied tendons to the 1st and 4th digits

only.

The M. flexor brevis digitorum presented simian peculiarities, for it
was composed of two parts : the larger calcanean part supplying the three
middle digits, the fifth toe being supplied by a muscular belly which, as is
common in Simiidae and other Primates, took origin from the long flexor
tendon.

The tendon of the M. flexor hallucis lougus provided slips for the fourth,
as well as the second and third digits.

The authors remark that the last two conditions constitute deviations
from the type of the white races, as pronounced as any up to that time on
record, but they clearly recognise that the occurrence of these anomalies in
a single individual affords but little justification for a general statement
affecting the race.

Peripheral nervous system and. sympathetic nervous
system. The observation made many years ago by Soemmering
and Jacquart, to the effect that the nerves are larger in the negro
than in the white man, does not appear to have been confirmed
by later writers.

The following observations are available in connection with
this part of our subject.

In a negro Turner observed ( J . A. and P. Vol. xiv. p. 244)
a large gangliform enlargement on the left splanchnic nerve.

In the same negro, the lesser occipital nerve was represented
by two distinct nerves ; and the ulnar nerve was formed by the
union of heads of origin from inner and outer cords respectively
of the brachial plexus (Wood, Proc. Roy. Soc., June 15, 1865, records
a similar condition in a negro). In another negro, Turner ( J . A.
and P. Vol. xxxi. p. 624) records an additional origin of the
phrenic nerve from the fifth cervical nerve : in the same negro the
gluteal and sciatic nerves were abnormal, and the cutaneous
branches of the obturator nerve pierced the muscle of that name.

With regard to the nerves of the lower limb the following
observations are available. From a large number (17) of dissec-
tions, Bardeen and Elting1 obtained results which shew that in
the negro races the type of lumbo-sacral plexus, known as the

1 Anatomischer Anzeiger, Band xix. s. 217.

390

THE SOFT TISSUES

[SECT. C

“ posterior ” type, is more prevalent than in the white races. This
statement holds good for both sexes alike. At the same time the
number of segments contributing nerves to this plexus seems to
be about equal in the black and white Hominidae alike.

In the dissection of the Bush-woman, to which reference has
already been made1, Flower and Murie found that the peripheral
nerves of the lower limb presented no anomalies of distribution,
as judged by the standard of the white races.

1 Journ. A. and P. Vol. i.

CHAPTER XV.

THE COMPARATIVE MORPHOLOGY OF THE
CENTRAL NERVOUS SYSTEM.

The study of the comparative morphology of the central
nervous system in general, and of the cerebrum in particular,
is fraught with unusual interest in view of the association of
psychological phenomena with this system. It may indeed be
said (notwithstanding the warning uttered in the earlier part
of this book as to the inexpediency of selecting as criteria of
comparison a single character, or the characters drawn from a
single morphological system) that the study of the brain, viewed
from this standpoint, constitutes an epitome of the whole study
of human morphology. For just as any one of the higher animals
may he regarded as a complex of morphological systems, so the
encephalon consists of a number of component parts; and just
as the existing mammals differ morphologically as the result of
specialisation having proceeded to different lengths in the various
systems, so when observation is restricted to the encephalon,
differences are seen to obtain among the members of various
sub-classes, orders, and families of mammals, according to varia-
tions in the extent of modification to which the several components
of this particular part of the nervous system have been subject.
Exactly, too, as the evidence of morphological conformation, taken
as a whole, is perfectly explicit as to the position of the Homi-
nidae in the Eutherian series, so also the evidence of this
particular group of tissues does not falsify the anticipations that
will have been formed from the examination of the skeletal, the
muscular, or other systems.

It is but natural, therefore, that a plan of campaign similar
to that of which an exposition has been attempted in the preceding

392

THE COMPARATIVE MORPHOLOGY

[SECT. C

Chapters should be pursued. And therefore it is that the headings
under which the central nervous system will be considered are,
(a) the Encephalon, ( b ) the Spinal Cord; and the characters of
each of these components will be briefly reviewed in relation
to (1) comparative morphology, (2) embryology, (3) variations,
and (4) palaeontology.

I. Comparative morphology. As might be expected in view
of the extraordinary manifestations of the Hominidae, the human
encephalon presents an example of remarkable specialisation when
compared with those of all other animals. The particular part
of the encephalon thus modified in Man is that to which the name
Neopallium is .applied, and our first enquiry must be made into
the relations of the neopallium to the other components of the
encephalon. Morphologically, the neopallium is derived from
that portion of the tube by which the central nervous system
is primitively constituted, which occupies its anterior extremity;
it forms part of the Telencephalon, the position of which is
represented in the accompanying diagram of these structures as
they appear in human embryos of about four weeks. (Cf. Fiers.
227 and 228.)

The Telencephalon as thus defined, gives rise to various
structures : ventrally, the cerebral component of the hypophysis
cerebri is derived from it; laterally, a vesicle projects, the rudiment
of the cerebral vesicle, the lower wall of which was observed by
Reichert to become thickened, while its upper wall remained
(for a period) comparatively thin. The thickened lower part
(which gives rise among other structures to the corpus striatum)1
was termed by Reichert “ Stammlappen,” in contrast to the
thinner upper portion, which was termed “Pallium.”

To these terms a third, viz. Rhinencephalon, was subsequently
added, but extended research especially on the side of comparative
anatomy, shewed that under both stammlappen and pallium was
included a heterogeneous assembly of structures, some of which
at least should, in accordance with the indications of morphology,
be added to the structures grouped under the third term, Rhinen-
cephalon. Moreover, as employed by various writers the limits
1 Cf. Elliott Smith, J. A. and P. 1901, p. 435, et seq.

CHAP. XV] OF THE CEREBRUM 393

of the several structures were but loosely defined, and confusion
was at its height when in 1901 Elliott Smith came to the rescue
with a series of proposals for the clear definition, upon morpho-
logical grounds, of the significance and limits of the descriptive
terms to be employed. Elliott Smith recognises in Mammalia the
following components of the fully developed wall of the cerebral
vesicle.

Fig. 227 (after Kollmann). The human encephalon at about the twentieth
day of foetal existence. The Telencephalon is that portion of the primitive neural
tube which is represented anteriorly to the interrupted line.

Fig. 228 (after His). The human encephalon at a stage corresponding to that
represented in Fig. 227. The nervous tube is here represented in section. As
in Fig. 227, the Telencephalon is that part which is situated anteriorly to the
interrupted line. For the full terminology of the divisions of the Encephalon in
this early stage, v. Barker, The Nervous System, p. 160 ; or van Gehuchten,
Anatomie des Centres Nerveux, p. 17.

(a) The basal pallium or pyriform lobe : the limits of which
are thus defined. (Elliott Smith, J. A. and P. Vol. xxxv.
p. 433.)

“ The anterior portion is closely applied, and attached to the
lateral aspect of the corpus striatum (Fig. 233), and extends
forward so as to pass into direct continuity with the olfactory

394

THE COMPARATIVE MORPHOLOGY

[SECT. C

peduncle, its peculiar (histological) structure undergoing a gradual
transition into the somewhat indefinite ‘ peduncular ’ formation ;
its antero-ventral part is covered by the thick mass of the tractus
olfactorius (lateralis) (Fig. 229, 4'), radiating fibres of which are
spread over the whole of the pyriform lobe. In its caudal part
the pyriform lobe becomes free from the corpus striatum, and
becomes a real ‘ mantle ’ (Fig. 233) which extends in the caudo-
mesial direction to become continuous with the hippocampus.”

( b ) The marginal ‘pallium (cf. Elliott Smith, Cat. Roy. Coll.
Surg. Mils., Physiol. Series, Vol. II. p. 142, et passim ; also
J. A. and P. Vol. xxxv. p. 499), or hippocampal formation,
includes “not only the hippocampus (sensu stricto) but also the

neopallium

OLFACTORY

BULB w

TUBERCULUM OLFACTORIUM

Fig. 229. Scheme of the mammalian cerebrum with the several components
indicated. Left lateral aspect.

In this, and the four following diagrams (kindly lent by lrofessor Elliott
Smith), indications are provided as follows, by means of numerals.

(1) The olfactory bulb.

(2) The olfactory peduncle.

(3) The olfactory tubercle (tuberculum olfactorium).

(4) The pyriform lobe. (47 ). The lateral olfactory tract.

(5) The “ paraterminal body.-”

(6) The anterior perforated space. . , , . , , , ,, , .

(7) The hippocampal formation, sharply differentiated into (a) the hippo-
campus, sensu stricto, and (b) the fascia dentata.

(8) The corpus striatum.

(<)) The rest of the hemisphere, consisting of a dorsal cap, which is the neo-
pallium.

CHAP. XV]

OF THE CEREBRUM

395

fascia dentata, the hippocampus nudus (Zuckerkandl’s Balken-
windung ), the supra- and pre-callosal vestiges of the hippocampus,
and the fornix (fimbria). (Figs. 231, 232.)

NEOPALLIUM

^. PYRIFORM
~*LOBE

OLFACTORY BULB

HIPPOCAMPAL

FORMATION

TUBERCULUM OLFACTORIUM

Fig. 230. Scheme of the mammalian cerebrum, with the several components
indicated. Mesial aspect. For references v. Fig. 229.

Fig. 231.
v. Fig. 229.

The central portion of Fig. 230 on a larger scale. For references

396

THE COMPARATIVE MORPHOLOGY

[SECT. C

Fig. 232. Scheme of the mammalian cerebrum with the several components
indicated. Ventral aspect. For references v , Fig. 229.

HIPPOCAMPUS

Fig. 233. Schematic section in a horizontal plane through the mammalian
cerebrum. For references v. Fig. 229.

OF THE CEREBRUM

397

CHAP. XV]

For Elliott Smith the rhinencephalon includes both (a) and
(b), the basipallium and marginal pallium, together with the
following structures (cf. Figs. 229 — 233, inclusive) :

the olfactory bulb,
the olfactory peduncle,
the tuberculum olfactorium,
the locus perforatus anticus,
the paraterminal body.

When the foregoing structures, together with the corpus
striatum and such portions of the wall as remain in a permanently
membranous or epithelial condition (covering the choroid plexuses
of the lateral ventricles) are eliminated, there still remains a
residue of the cerebral vesicle unaccounted for. This is what
Elliott Smith recognises as

(c) The dorsal pallium, or neopallium. “ A morphologically
well-defined cortical area, which is the most important feature of
the whole brain, or for that matter, of the whole body in the
higher Eutheria; that part of the cerebral hemisphere which is
responsible for the greatness of the mammalian brain, and over-
shadows in its greatness and usurps many of the functions of all
the other regions of the nervous system, that great progressive
cortical field, the high development of which becomes in the
Mammalia the great fundamental condition of their survival ; a
great unlimited area (far removed from the disturbing influences
of the purely ‘ administrative ’ parts of the nervous system), where
‘ impulses of diverse nature ’ coming from all regions of the body,
and from all the sense organs, majf ‘ meet and play upon each
other

Such then is the definition and such the status of the neopal-
lium in the Mammalian encephalon. In the Reptilian encephalon,
the basipallium, the marginal pallium, the remaining constituents
of the rhinencephalon, and the corpus striatum, account for prac-
tically the whole of the (non-epithelial) cerebral vesicle : yet even
in the brain of the reptile (e.g. Hatteria), a rudiment of the
dorsipallium (neopallium) is recognisable ; and from the Reptilia
upwards, the importance of the neopallium increases progressively,
with concomitant reduction of the rhinencephalon, till a climax

398

THE COMPARATIVE MORPHOLOGY

[SECT. C

is xeached m the brains of the Hominidae. Before passing on,
two more remarks must be added to this somewhat lengthy but
most essential preface ; in the first place, the several structures
here enumerated, have been differentiated largely by the aid of
histological methods, which have here been applied with the result
of demonstrating peculiarities characteristic of each. Secondly,
to each of these three divisions of the pallium is attached a special
commissural system, the basipallium and marginal pallium sharing
the larger part of the ventral commissure (anterior commissure of
human anatomy), and of the primitive dorsal commissure now
recognisable only in the psalteriuin of the fornix ; while the neo-
pallium of one hemisphere is connected with its fellow of the
opposite side by means of a commissure developed later in the
evolutionary history of the Mammalia than either of the foregoing,
and known as the corpus callosum1. The size of the corpus
callosum bears a direct relation to the mass of the neopallium,
and in such Mammals as possess the most highly developed neo-
pallium, the corpus callosum has attained its maximum development
in point of size, overshadowing the more archaic ventral and dorsal
(psalteriuin) commissures; to gain a proper appreciation of the
latter, the brains of the more lowly Mammals or of Reptiles, wherein
the corpus callosum has not yet been evolved2, must be examined.
(Cf. Figs. 234 and 235.)

1 This statement requires some qualification. Although the corpus callosum,
the psalteriuin (dorsal commissure), and the ventral (anterior) commissure are
recognisable as distinct entities in the brains of the higher Eutheria, yet it appears
from the researches of Elliott Smith (cf. Linnean Transactions, 1900, Vol. vm.
p. 47) that the commissure fibres of the neopallium when first they appear in the
vertebrate series, i.e. in Reptiles (cf. brain of Hatteria), cross in the latter, viz. the
ventral commissure, the dorsal commissure being retained for hippocampal fibres.
But with the increase in the number of neopallial fibres, the ventral commissure
becomes inadequate to the task imposed upon it, and the neopallial fibres, forsaking
it, betake themselves to the dorsal commissure, of which they thenceforth constitute
a separate and entirely distinct section, viz. the corpus callosum. Elliott Smith
has most admirably demonstrated the series of Mammalian brains in which this
evolution may be phylogenetically traced, and points out that the phylogenetic
history is confirmed by the evidence of ontogeny as provided by Martin’s researches
on the embryology of the brain in the cat. Incidentally, important contributions
have been made to a true appreciation of the morphological significance of the
septum lucidum of the higher Eutherian brain.

2 This is in apparent contradiction to the results of H. F. Osborn’s researches

CHAP. XV]

OF THE CEREBRUM

399

When we examine the brains of Eutherian mammals in the
light of the foregoing facts, we find that throughout this Section,
the regions of the mid-brain, the pons varolii, and the medulla

Fig. 234. Fig. 235.

Fig. 234. Coronal section through the cerebral hemisphere of a Reptile
(Hatteria). Differences of shading demarcate the marginal pallium from the
pyriform lobe, and the corpus striatum. The neopallium is developed between
the two former portions of the cerebrum, and is indicated very vaguely (for its
extent is not actually known) by a dark band at the junction of the marginal pallium
and pyriform lobe.

Fig. 235. Coronal section through the cerebral hemisphere of a lowly Mammal
(Ornithorhynchus : Prototheria) shewing the limits of the marginal pallium and
the neopallium (cf. Fig. 236). The corpus striatum does not appear in this
section, and the pyriform lobe is merged in the lower part of the marginal
pallium. The mesial aspect (as in Fig. 234) is to the left.

oblongata persist in a remarkably stable condition. With regard
however to the telencephalon we find a considerable range of
variation, the general nature of which may (as has already been
indicated) be briefly described as consisting in progressive reduc-
tion of the rhinencephalon (as defined by Elliott Smith, v. supra)
and its commissures, with increase in the neopallium, and its
commisural tract, the corpus callosum. Increase in the neopallium

(cf. Minot, Human Embryology , pp. 684 et seq). Osborn claims to have demon-
strated the presence of the corpus callosum in Birds, Reptiles, and Amphibia, and
believes that it will be shewn to exist in Fishes. But a comparison of Osborn’s
descriptions (op. cit.) with those of Elliott Smith (Linn. Trans. 1900, Vol. vm.
p. 47 et seq., see also foot-note No. 1, p. 398) leads one to believe that the
commissure described by Osborn as the corpus callosum in the lower forms,
corresponds to what Elliott Smith calls the dorsal commissure, a precursor of the
(typically Eutherian) corpus callosum. At the same time, Elliott Smith, as will be
seen in the preceding note, considers that the dorsal commissure is composed of
hippocampal fibres only, whereas the primitive corpus callosum, according to Osborn,
would contain neopallial fibres. So that the correspondence is not exact.

400

THE COMPARATIVE MORPHOLOGY

[SECT. C

implies increase in that portion of the wall of the cerebral vesicle
from which it is derived, and of that wall the external or
superficial part is chiefly affected. The superficial limits of the
basipallium, the marginal pallium, and the dorsi- or neopallium
are indicated in part by certain cerebral fissures, known as the
rhinal and the hippocampal fissui'es respectively, which are most

easily recognisable in the brains of the most lowly mammals.
(Cf. Fig. 236.)

When, in consequence of the requirements of the animal, the
neopallial surface increases in extent, it is thrown into folds, so
that the fissures on the cerebral hemisphere to which reference has
just been made, are supplemented by furrows formed on the surface
of the neopallium. It will be noticed, however, that these furrows
have a morphological significance and value quite distinct from
those of the rhinal and hippocampal fissures, which nevertheless
persist and are still recognisable, however great the development
of the neopallium, and however complicated the system of neo-
pallial furrows may be. The brains of most of the Eutheria, and
of the Primates in particular, including the Hominidae, are charac-
terised by the possession of a number of such neopallial furrows,
which divide up the neopallial surface into a series of convolutions
familiar to students of the human cerebral anatomy, while at the
same time the rhinal and hippocampal fissures persist and de-
marcate the basipallium from the marginal pallium, and the latter
from the neopalliutn.

When we pass from the study of brains with non-furrowed
(or non-convoluted) pallia to that of brains in which the furrows,
and the convolutions bounded by them, are numerous, the question
arises, whether or not there is a single primitive type of the
convoluted neopallium, of which all other convoluted neopallia

Fig. 236. Mesial aspect of the right cerebral
hemisphere of a lowly Mammal (Ornithorhyn-,
chus : Prototheria). The rhinenceplialon and
marginal pallium are shaded to distinguish
them from the neopallium. The limiting
fissures, viz., the rhinal and hippocampal
fissures are shewn : and the dorsal and ventral
commissures are seen to be unaccompanied by
a callosal commissure. Cf. also Figs. 234 and

Fig. 236.

OF THE CEREBRUM

401

CHAP. XV]

are the more or less modified outcome. The answer to this
question seems, from the stock of evidence at present available,
to be in the negative. Investigations into these questions take
us far beyond the limits of the Order Primates, and in the present
place only a brief statement of the results of some of the
researches that have been carried out in the Mammalia can be
given.

In the succeeding paragraphs some of the factors by which the
increase (with consequent folding) of the neopallium is determined,
will be considered, though not in order of importance, as to which
there is so far no criterion1.

In the first place it appears that the habitat and the mode
of life of an animal react on the conformation of the neopallium ;
for in relation to these stands the development of the several
senses ; now the sense-organs find in the superficial portions of
the neopallium, representation over a certain area which will vary
in extent with the employment of the organ, and this will to some
extent at least be modified, as we have suggested, by the environ-
ment of the particular animal.

Secondly, the absolute mass of an animal exercises an influence
upon the extent of surface needed for the appropriate representa-
tion (upon the neopallium) of the various senses, in accordance
with the well-known fact that while the bulk of a spherical organ
(to which the brain may be compared) is increased in the ratio of
the cube of its radius, the area of its surface is increased in the
ratio of the square only of that radius. Therefore of two animals
of equal sensitiveness (using the term in the widest significance),
the one, if minute, can provide the requisite extent of cortex upon
an almost smooth neopallium, while the second and larger form
will need perhaps a very high degree of convolution to increase
the cortical surface to the appropriate amount.

Thirdly, though by no means least, the status of the animal as
regards morphological evolution has to be taken into account.
For it appears that certain animals, even when due allowance has
been made for (1) environment, and (2) for their mass, are still

1 The chief researches to be studied in this connection are (1) Manouvrier,
MCm. de la Soc. d’Anth. de Paris, 2° SCrie, t. m. 1885, pp. 137—326. (2) Dubois,

Bull, de la Soc. d'Anth. de Paris, 4° S6rie, t. vm. pp. 337 et seq.

D. M.

402

THE COMPARATIVE MORPHOLOGY

[SECT. C

provided with an excess of neopallium, as compared with other
animals for which the corresponding allowances have been made.
Such an excess of neopallium may or may not be referable to
the possession of distinct faculties or senses: these we must for
the moment leave out of account, only remarking that the surplus
of neopallium is accommodated by folding of the surface, just as
though it had been provided in response to either of the two
requirements (environment and mass) first described.

The following considerations arrest us at this stage of our
enquiry; (1) on the one hand, we find in every Order of the
Mammalia (or the Eutheria, for it will be simpler for the moment
to restrict the range of study to these) examples of animals (a) of
varying habitat, and (b) of minute and of great mass respectively.
We shall therefore not be surprised to find that even within the
limits of any one of these (Eutherian) Orders, a series of brains
can be demonstrated, in which are represented all grades of
complexity in the arrangement of the neopallial furrows (and
convolutions), varying from an almost absolutely smooth surface
upwards. The primitive type of neopallial surface is apparently
a smooth, unfurrowed one1.

From such a smooth neopallium, evolution in the Eutheria
has resulted in the production of furrowed and convoluted modi-
fications of several kinds, so different in their terminal stages (as
represented by existing forms of Eutheria) as to render the
determination of the homologies of most of the furrows a matter
of considerable difficulty. It is noteworthy that within the limits
of each of the several Orders of Eutheria (as established in
accordance with the definitions laid down in an earlier chapter),
there is a general resemblance of type in respect of the arrange-
ment of these furrows, and by selecting a series of exanqiles from
one Order, the evolution of the combination of furrows characteristic
of that Order can in many instances be demonstrated, starting from
a form (still within the Order) in which the neopallium is primi-
tively smooth. This statement holds good for the Primates, and
consequently it follows that within each Eutherian Order the
factors already mentioned have to be taken into account, and in

1 Among the numerous paradoxes in this subject the presence of a well-convoluted
noopallium in Echidna (Prototheria) is not the least striking.

CHAP. XV]

OF THE CEREBRUM

403

addition, consideration of the influence of mechanical factors acting
upon the form or proportions of the brain-case must not be
omitted.

(2) Secondly, we find even from very superficial inspection,
that in the Hominidae, the encephalon is modified in the same
way as the corresponding organ in the Primates ; and hence the
association of the Hominidae with these Eutheria receives its final
confirmation. But further, the members of this same Order of
the Primates present us with the most striking examples of
Eutheria in which the amount of neopallial extension is in excess
of what would appear to be demanded by (what may be regarded
as) the comparatively lowly claims of development of sense organs,
and of actual mass. This phenomenon may be expressed by de-
scribing the “ cephalisation ” of the Primates as in excess of that
of other Eutheria.

In the Primates too we find, in accordance with the statements
just made, that it is possible to demonstrate a series of brains, the
neopallial characters of which range in complexity from the smooth
unfolded organ of Tarsius, to the highly convoluted one of the
Hominidae.

An attempt to trace the homologies of the several constituents
of the encephalon in general, and of the characteristic neopallial
furrows of the Hominidae, through the Eutherian series would
take us beyond the scope of the present account, which is therefore
limited to the consideration of a few selected features of mor-
phological interest. It is proposed therefore to deal briefly in
succession with the

(a) rhinencephalon.

(b) marginal pallium.

( d ) the principal neopallial sulci.

(a) rhinencephalon. In the human brain the representative
elements are,

(1) The olfactory nerve fibres and bulb.

(2) The olfactory nerve, an attenuated representative of
the tractus olfactorius of primitive mammals : this attenuation
is, as has been mentioned, very characteristic of the brains of

26—2

404 THE COMPARATIVE MORPHOLOGY [SECT. C

Anthropoidea, which thus differ markedly from those of Lemur-
oidea: in the latter the more primitive mode of conformation
obtains. (Cf. Fig. 37.)

The reduction occurs as it were suddenly, in the transition from
Lemuroidea to Anthropoidea, and is undoubtedly associated with
the great neopallial increase in the latter Sub-order.

(3) The “external root” of the olfactory nerve marks the
course of the olfactory tract, which is thus traceable outwards
across the Sylvian vallecula, then skirting the anterior perforated
space (a tuberculum olfactorium being indistinguishable, so
flattened has the surface become locally), to be lost in the anterior
extremity of the “uncinate gyrus”; in this anterior part, which is
absolutely distinct from the posterior part of the uncinate gyrus,
is recognised all that represents (in the Hominidae) the pyriform
lobe.

The exact demarcation between the olfactory tract and pyri-
form lobe remains to be determined. Elliott Smith1 speaks of the
“radix lateralis” of the olfactory nerve as representing the anterior
part of the pyriform lobe in Man, and an absolutely precise
delimitation would probably be determined by histological ob-
servations. About the middle of intra-uterine existence, the
developing cerebrum shews the clearest evidence of the continuity
of the tract with the anterior part of the uncinate gyrus, a
continuity which is subsequently to a large extent obscured.
(Cf. Fig. 237.)

(4) The septum lucidum and the gyrus subcallosus represent
the primitive corpus paraterminale : the former is recognisable
in the Hominidae as in the Primates in general, and varies in the
latter with the extent of the corpus callosum.

(5) The anterior commissure of the human brain represents
the primitive ventral commissure, traceable as such throughout
the Primate series.

(6) (1) The hippocampus major, the band of Giacomini, the
fascia dentata,the fimbria and fornix are the foremost representatives
of the marginal pallium, and are traceable throughout the Primate
series. In the Hapalidae it is noteworthy that the fornix com-
missure is very small and placed far forward near the anterior

1 J. A. and P. Vol. xxx. p. 199.

CHAP. XV]

OF THE CEREBRUM

405

commissure. (Beevor, quoted by Elliott Smith, Linn. Trans, vm.
10, p. 332, Relation of the Fornix to the Margin, etc.; J. A. and
P. Vol. xxxii. Fig. 23.)

Fig. 237. Lateral (A), and basal (B) views of the right cerebral hemisphere of a
human foetus of five months. In (A) the transverse occipital sulcus is an artefact.

(2) The small “Balkenwindung” (or gyrus A. Retzii), the
striae Lancisii, and the gyrus geniculi are all referable to the
marginal pallium. The former structure (Balkenwindung) is
distinctly less evident in the brains of the lower Primates than in
the Hominidae. Elliott Smith1 quotes Zuckerkandl’s description of
this structure in the Lemuroidea2.

1 Linn. Trans, loc. cit. p. 331.

2 “Beitr. zur Anat. des Riecheentrums.” Sitz. Alcad. Wiss. I Vien. Math.-nat.
Cl. Bd. cix. Abth. iii. 1900.

406

THE COMPARATIVE MORPHOLOGY

[SECT. C

The incisura temporalis represents the posterior part of the
rhinal fissure: it is situated in the Hominidae and higher Primates
on the ventral aspect, but in the lower Primates (Lemuroidea) on
the lateral aspect of the hemisphere. The collateral sulcus does
not represent any part of the rhinal fissure. Elliott Smith1 states
his view most categorically on this point, confusion on which is
attributable partly to the inclusion of rlunencephalon (pyriform-
lobe-constituent) and neopallium in the comprehensive term
“uncinate gyrus2.” Having thus accounted for such parts of the
cerebral hemisphere of the Hominidae as are referable to the
rhinencephalon, attention may be transferred to the neopallium.

(c) In the Hominidae, the neopallium is to be considered as
responsible to a large extent for the characteristic form of the
cerebral hemisphere. Thus the fulness and rounded appearance
of the hemispheres, and the degree to which the cerebellum is
overlapped by them, are attributable to this factor, though as
regards the latter character (the cerebral overlap), the Hominidae
are surpassed by a comparatively lowly member of the Anthro-
poidea, viz. Chrysothrix, a genus of small new-world monkeys
(Cebidae). It is thus evident that even this character does not
confer upon the Hominidae a position apart from all other
Primates: nor indeed can the character of the possession of a
posterior cornu of the lateral ventricle, for this (cf. Elliott Smith,
Cat. of the Museum of the Royal College of Surgeons, Phys.
Series, Vol. n. p. 384, and Linn. Trans. 1903, Vol. VIII. Part 10,
pp. 379, 380, 381), though admittedly not present in the Lemur-
oidea is a feature of the brains of the lowest Anthropoidea,
viz. the Hapalidae.

(d) The complicated arrangement of sulci and convolutions of
the surface of the neopallium of the Hominidae remain for con-
sideration. The degree of complexity of these sulci constitutes
a distinguishing feature of the Hominidae within the Primates.
It may however be remarked that not even in virtue of the
combination of so highly convoluted a neopallium together with
a much reduced rhinencephalon, do the Hominidae stand at the
head of the Eutherian series, for in respect of this combination,
believed at one time to be their absolutely distinctive attribute,

1 Linn. Trans. 1903, Vol. vin. Part 10, p. 390, footnote.

2 Elliott Smith, op. cit., loc. cit.

OF THE CEREBRUM

407

CHAP. XV]

the Hominidae are surpassed by certain Cetacea, in which both
characters (viz. complexity of convolutions, and reduction of
rhinencephalon) have advanced to a further stage than in the
former. Due allowance being made for this consideration, it
remains to review the characters and disposition of the sulci and
convolutions, commencing with the region of the central lobe or
Island of Reil. This part of the neopallium, when traced through
the Primate series, will be found to lose the complexity of surface
due to the sulci which indent its surface in the Hominidae and
Simiidae. In the lower Anthropoidea and Lemuroidea,' it presents
the aspect of a smooth eminence of neopallium from which the
frontal, and in turn the orbital opercula are withdrawn as the
type recedes further from the Hominidae, while the temporal
operculum persists throughout the Order. Reduced thus to its
simplest terms, the central lobe is revealed as a portion of the
neopallium, closely related and attached to the corpus striatum:
research extended beyond the limits of the Primates, indicates
that this localised retention is accompanied by a downward flexion
of the portion of that part of the neopallium which lies posteriorly
to the fixed area. Similar research shews (cf. Elliott Smith, Gat.
Mus. R. G. S. p. 368) that this flexion results in the production of a
furrow or’ group of furrows upon the surface of the fixed area, and
immediately above the rhinal fissure. This furrow (or the com-
bination of a group thus developed) is well-marked in Carnivora,
in the brains of which it has been described as the “pseudo-
sylvian fissure1.” (Cf. Fig. 238.)

Above and anteriorly to the fixed area, is found (in Carnivora)
a sulcus called the supra-sylvian, which with the post-sylvian sulcus
(Fig. 238), forms one of a system of furrows concentrically arranged
in tiers above the fixed area. The brains of Lemuroidea shew that
the supra-sylvian and pseudo-sylvian furrows join, and the area
included between them is the central lobe, insula, or Island of Reil,
the superior limiting sulcus of which is seen to be the modified
derivative of the supra-sylvian sulcus, while the posterior limiting
sulcus represents the pseudo-sylvian furrow, and the parallel
sulcus the post-sylvian furrow. But for the demonstration in

1 Elliott Smith, Catalogue Mus. R. C. S. p. 368, and J. A. and P. xxxvi.
p. 312. Holl’s work.

408

THE COMPARATIVE MORPHOLOGY

[SECT. C

SULCUS

SULCUS SULCUS SUPRA- SULCUS

CORONALIS CRUCIALIS SYLVIUS LATERALIS

BULBU8

OLFACTORIU8

8ULCU8 OR BITALIS

SULCUS

POST-

LATERALIS

SULCUS

PCSTSYLVIUS

SULCUS

PSEUDOSYLVIUS

SULCU8 DIAQONALI8

FISSURA RHINALI8

Fig. 238. Lateral aspect of a cerebral hemisphere upon which are indicated the
most constant of the neopallial furrows found in the Eutheria. The pseudo-
sylvian and supra-sylvian sulci are to be particularly noticed. (This and the follow-
ing illustration are kindly lent by Dr Elliott Smith.)

SULCUS INTEROALARI8

SULCUS

ROSTRALIS

FISSURA HIPPOCAMPI

SULCUS RETRO-
CALCARINUS

SULCUS

CALCARINUS

SULCUS

COLLATERALIS

FISSURA

RHINALIS

Fig. 239. Mesial aspect of a cerebral hemisphere upon which are indicated the
most constant of the neopallial furrows found in the Eutheria. The calcarine and
intercalary sulci are to be particularly noted.

OF THE CEREBRUM

409

CHAP. XV]

detail of these points reference must be made to the masterly work
of Elliott Smith. It remains to add that the central lobe of the
Hominidae is bounded further by an anterior limiting sulcus ; in
the Simiidae this is recognisable in the fronto-orbital sulcus, which
in turn is regarded by Elliott Smith as homologous with the sulcus
diagonalis of lower forms; but neither the fronto-orbital sulcus,
nor other representative of the sulcus diagonalis (Fig. 238), can be
traced in the Primates (excepting some Lemurs) lower than the
Simiidae (unless indeed an offshoot of the orbital sulcus is called
in question: there is some evidence in support of this). Tracing
the evolution upwards, the neopallial surface on the distal sides of
each of these limiting sulci of the island of Reil becomes opercular
in turn, that portion which lies beyond the pseudo-sylvian (between
it and the post-sylvian) first increasing, next that beyond the
fronto-orbital sulcus (the anterior limiting sulcus of Reil), and
lastly that beyond the supra-sylvian sulcus (the superior limiting
sulcus of Reil) ; the latter increase is associated with an increase
in tortuosity, though not in relative mass, of the inferior frontal
convolution, progress in evolution being here demonstrable by
the comparison of the brains of Simiidae with those of the
Hominidae. Of the sulci just mentioned, it may be remarked
that the supra-sylvian is regarded as the most archaic, and as
recognisable throughout a large series of Eutherian brains besides
those of Primates, in all of which it is seen as the sylvian fissure.
(Cf. Fig. 241.)

It will be convenient to arrange the notes dealing with the
more important sulci in tabular form, commencing with the orbital
or tri-radiate sulcus of human anatomy. (Cf. pp. 410, 411.)

The conclusion is that the whole Primate series leads up
progressively to the type of brain found in the Hominidae.

With the accompanying table (pp. 410, 411) this section of the
account of the cerebral hemispheres must be brought to an end.
There remain the more posteriorly-situated constituents of the en-
cephalon. Of these the trapezium will attract some attention: this
band of fibres forms a commissure whereby the auditory nerve
impulses may decussate, and in the Hominidae this band is not
visible on the surface of the medulla oblongata. Such complete
submergence of the trapezium is characteristic of the Hominidae,

Name in Human
Anatomy

Tri-radiate (orbital)
sulcus *.

Inferior frontal sul-
cus*.

Central sulcus (Ro-
lando).

Intra-parietal sulcus.

Sulcus lunatus, or
Afifenspalte of
German authors.
Though recognis-
able in certain ab-
normal human
brains (viz. those
of some microce-
phalic idiots), the
sulcus lunatus is
commonly de-
scribed as absent
from the brains of
the Hominidae,

Appearance in the series of
the Primates

This sulcus is practically con-
stant throughout the Primates,
though it is not tri-radiate in
the lower forms (Lemuroidea).
In some brains of Lemuroidea
the sulcus is not present.

This is represented by the sulcus
rectus, a furrow well-marked
in the Cercopithecidae, and
recognisable throughout the
Primates.

This furrow is recognisable
throughout the higher Pri-
mates: it disappears, or is
quite rudimentary, in some of
the smaller Cebidae, and is
absent in the Hapalidae ; in
the Lemuroidea, it is repre-
sented by a mere depression,
except in Perodicticus, and
certain extinct Lemurs (Glo-
bilemur and Nesopithecus).

Recognisable throughout the
Primates ; in Clirysothrix
(Cebidae) it blends with the
sylvian fissure.

Most distinct in the Simiidae,
Cercopithecidae, and some Ce-
bidae (Cebus), but in the
smaller Cebidae, in the Hapa-
lidae, and all the Lemuroidea
it is deficient. It must be
admitted that though distinct,
the occipital operculum and
sulcus lunatus of the Homini-
dae are degenerate or vestigial
as compared with the corre-
sponding parts in the Cerco-
pithecidae, or even the Simii-
dae.

Probable representative in lower
Eutheria (cf. Fig. 241)

The orbital sulcus of the Primate
brain is regarded as homologous
with the pre-sylvian sulcus
which is so distinct in the
brains of some Carnivora.

The homologue of the sulcus
rectus is found in the sulcus
coronalis of the brains of the
Carnivora. This sulcus is one
of early appearance in the
Eutherian series.

The central fissure is identified
(though there has been much
discussion on this subject) with
the sulcus crucialis which is so
conspicuous in the brains of
Dogs, Bears and other Carni-
vora. It does not seem clear
which of the two elements from
which the human central sulcus
is embryologically developed, is
thus represented.

The intra-parietal is believed to
represent the S. lateralis, while
its ramus post-centralis supe-
rior is the S. ansatus of Carni-
vora.

Not traceable beyond the An-
thropoidea, in which the need
for its development depends on
the increased size and com-
plexity of the occipital neo-
pallium.

owing to the occipital operculum (to which it owes its existence) having been thrown
back by convolutions emerging from the depths of the sulcus. Cunningham admitted
the possibility of its occurrence in very rare instances, and Mendel (Neurologisches \
Centralblatt, Yol. nr. p. 217) describes one such case and cites others.

Bischoff described (cf. Cunningham, Cunningham Mem. vii. pp. 60 et seq.) the
ape-fissure as a transitory characteristic of the human foetal cerebrum, and named the
sulcus thus considered homologous with the ape-fissure, the fissura perpendicularis
externa. Elliott Smith has however recently shewn ( Anatom . Anzeiger, Band xxrv.
No. 8) that the fissura perpendicularis externa is really an artefact, and the result
of the impression made upon the soft hemisphere, by an inward projection of the
membrane in the lambdoid suture.

Elliott Smith (Cat. Mus. Boy. Coll. Surg. London) mentions the occurrence of the
sulcus lunatus in the brain of a (normal) Egyptian native (op. cit. p. 473), and in
a recent communication to the Anatomischer Anzeiger (Band xxiv.) adduces numerous
instances of the occurrence in the brains of Egyptians, Soudanese negroes, and other
lowly races. Statistics as to the frequency of occurrence of the sulcus are now being
collected and notes upon the subject will be found in Chapter xiv. The sulcus marks the
lateral limit of Gennari’s stria. (Elliott Smith, Anat. Anz. xxiv. 16, 17.)

Name in Human
Anatomy

Calcarine sulcus*.

Internal parietoocci-
pital sulcus.

Calloso-marginal sul-
cus.

Collateral sulcus

Appearance in the series of
the Primates

Constant throughout the Pri-
mates. The portion which is
represented by the projection
of the calcar avis, on the in-
ternal aspect of the ventricle,
may be supplemented by pos-
teriorly-situated furrows which
blend with this, the “ true ”
calcarine sulcus.

This sulcus consists of a dorsal
and a ventral element. Both
are lost in the lowest Anthro-
poidea (smaller Cebidae and
Hapalidae), and the internal
parieto-occipital sulcus which
is so evident in the Lemuroi-
dea is justifiably regarded as
the equivalent of the ventral
component alone of that sulcus
in the higher Anthropoidea.
The sulcus is preferably named
paracalcarine in the Lemurs.

Becognisable throughout the
Primates, and particularly
well-marked in the brain of
Cheiromys (cf. Figs. 239 and
240) (Lemuroidea) ; it is how-
ever deficient in Hapale (An-
thropoidea).

This sulcus is developed in
response to the demands of
increasing neopaliial surface
near the calcarine sulcus. It
is intelligible therefore that
it can only be traced down as
far as the Cebidae, and that
in the lowest Anthropoidea
(Hapalidae), as in the Lemu-
roidea, it should be deficient.

Probable representative in lower
Eutheria (cf. Fig. 241)

Represented in almost every Eu-
therian order, the exceptions
being the Insectivora and Ro-
dentia. It forms part of a
sulcus called, from its situation,
the splenial sulcus.

No distinct representative of this
sulcus can be recognised be-
yond the Primates, in which its
appearance is associated with
the increased extent of the neo-
pallium at the occipital end of
the hemisphere.

As the “ inter-calary ” sulcus, it
forms part of the splenial
sulcus of Carnivora, etc.

The sulcus is possibly represented
by small isolated sulci in some
non-Primate brains, but no
homology has been definitely
established.

* The sulci thus marked, together with the supra-sylvian sulcus (the S. limitans superior
of Reil) are the most archaic in the Eutherian series. (Cf. Figs. 238, 239, and 241.)

Cctllo& o - ma xa i na l
SuIcuS

'Pa \-a '

ca\caK,

'De

s u\cus\

Calcarine.

Sulcu S

Fig. 240. The mesial aspect of the left cerebral hemisphere of Cheiromys
madagascariensis: the calloso-marginal or intercalary sulcus is well-developed.

412

THE COMPARATIVE MORPHOLOGY

[SECT. C

for in the Simiidae the trapezium is slightly exposed, and becomes
fully visible in the Cercopithecidae.

Fig. 241. Diagram (after Elliott Smith) to represent the most constant and
archaic sulci on the surface of the cerebral hemisphere of the higher mammalia.
The indications are as follows :

Bo : Bulbus olfactorius.

Sd: Sulcus diagonalis.

Sps : Sulcus pseudo-sylvius.
Sp : Sulcus post-sylvius.

SI : Sulcus lateralis.

Scr: Sulcus crueialis.

So: Sulcus orbitalis.

Fr: Fissura rhinalis.

Ss : Sulcus supra-sylvius.
Spl: Sulcus post-lateralis.
Sa: Sulcus ansatus.

Sco: Sulcus coronalis.

The Cerebellum. The morphology of the higher types of
cerebellum is still under discussion, but a few remarks on recent
contributions to this subject seem to be called for. The system of
nomenclature current in anatomical text-books has long been
recognised as unsatisfactory, and indeed misleading in the enquiry
into the morphology of the cerebellum, and an amended nomen-
clature was at an early period seen to be a prime necessity. But
while the human cerebellum was taken as the standard of
comparison, the conceptions that prevailed as to the constitution
of the organ were ill-defined and imperfect. The attention of
morphologists having been directed to the simpler mammalian
forms of cerebellum, an amended nomenclature was soon proposed,
and it is worthy of remark that this was based on the recognition
of the identity and constancy of certain fissures which demarcate
the component parts of- the organ. But the several schemes

OF THE CEREBELLUM

413

CHAP. XV]

proposed have not yet been reconciled, so that it is now necessary
to review some of the more important of these.

Of the various contributors to a fuller knowledge of this
subject Elliott Smith and Bolk stand out preeminently. While
these writers treat principally of the comparative anatomy of the
cerebellum, the embryological side has been studied by Bradley1,
to whom we owe a detailed exposition of the conflicting views that
have been formed'-. As a result of these researches, it appears in
the first place, that unlike the cortex of the cerebral neopallium
(which expands in several directions), the surface of the cerebellum
tends to increase in two directions principally, expansion being
practically confined to the sagittal and transverse axes of the
organ.

In the former (sagittal) direction, expansion finds expression in
a series of transversely-directed sulci, most distinct in the middle
portion of the cerebellum ; but in the lateral portions, expansion
in a transverse direction accompanies sagittal expansion, and the
sulci which indicate such increase of surface are accordingly
arranged in a more complicated manner than in the mesial part of
the organ.

In the mesial part, a particular sulcus was soon recognised as a
definite morphological landmark. To this sulcus, which is trans-
verse in direction, various names are applied, such as sulcus furcalis
(Stroud), sulcus primarius (Kuithan), fissura prima (Elliott Smith).
The cerebellum is hereby divided into anterior and posterior
segments, separated by the sulcus, but the further subdivision of
the cerebellar mass provides material for controversy.

Following on the recognition of the fissura prima, the separation
of the floccular lobe (consisting on each side of a flocculus and a
paraflocculus) as a morphological entity, must be mentioned as
a step in advance. But again, opinions differ as to the connections
of the floccular lobe and the intermediate mass of the cerebellum.
Thus Elliott Smith3 describes the cerebellum as composed of the
two floccular lobes, and an intermediate portion subdivisible into
three successive segments demarcated by fissures termed fissura

1 Journ. A. and P. Yol. xxxvii.

2 Cf. Bradley, J. A. and P. Vol. xxxvin. Part 4.

3 Journ. A. and P. Yol. xxxvi.

414

THE COMPARATIVE MORPHOLOGY

[SECT. C

prima and fissura secunda respectively. Between the floccular
lobes and the intermediate portion pass copulae or bands. It
should be noticed too, that this junction is held to be effected
between the floccular lobes and the posterior portion of the inter-
mediate mass. Bolk1 has put forward a slightly different scheme,
according to which the cerebellum as a whole is divided into an
anterior portion separated by the fissura prima from a posterior
portion. It is further stated by Bolk, that while the anterior
portion is affected by a tendency to expansion which is sagittal in
direction, acting on all regions of this portion alike, the posterior
segment (behind the fissura prima) has been differently modified in
growth ; so that while its more mesial part has (like the whole
of the anterior segment), expanded in the sagittal plane, its lateral
parts have increased in both the sagittal and transverse directions.
This leads to the distinction (in the posterior segment) of a median
part (corresponding to part of the median vermis of the old
anatomical nomenclature) and two symmetrical lateral parts. The
transverse expansion of the latter accounts for the projection
of the floccular lobes on each side. Further, the connection of the
floccular lobes with the intermediate part is effected according to
Bolk (who herein disagrees with Elliott Smith) in the region
immediately behind the fissura prima. (Elliott Smith, v. supra,
locates this connection further back.)

Such2 3 are the two principal views on the subject of cerebellar
morphology, and when the enquiry is directed to the features
of the human cerebellum it will be realised, that in the first place,
the fissura prima is clearly recognisable : the floccular lobes (jiara-
flocculus and flocculus) are much reduced in the Hominidae as
compared with the Cercopithecidae and lower Primates, the
Simiidae occupying an intermediate position in this respect. The
human cerebellum is further characterised by the exuberance
of that lateral component of the posterior segment known as the
lobulus ansiformis (crus primum)8, while, as already mentioned, the
more distal component of the same portion (which is recognised

1 Monatsschr. filr Psychiatric und Neurologic, 1902.

- Elliott Smith’s last impel- (1903) in the Monatssclir. filr Psychiatric und Neuro-
logic is not accessible to me.

3 Bolk, op. cit. pp. 460 et seq.

CHAP. XV] OF THE CEREBELLUM 415

in the floccular lobe) is attenuated. The evolution of these
characteristic features of the human cerebellum can be traced
in the series of the Primates ; some of the lowlier members of this
Order, and particularly Tarsius spectrum, present an extremely
primitive and undifferentiated form of cerebellum ; the Galaginae
provide examples of another interesting and intermediate stage in
the evolution of the organ as found in the higher Primates.

It is thus noteworthy that the Order Primates is sufficiently
comprehensive to include examples of almost every stage in the
evolution both of the most highly complicated forms of cerebrum
and of cerebellum.

The Spinal Cord. When we pass from the study of the brain
to that of the spinal cord we find the evidence more scanty and
less accessible in the latter case. In an earlier chapter mention
was made of the distinctive feature of the Mammalia, consisting in
the specialisation and increase in the encephalon, and hence it
will be intelligible that the cord of mammals is relatively smaller
in bulk (when compared to the brain) than in other vertebrates.
This statement applies to the members of the Order Primates
among the Mammalia, and to its significance allusion has already
been made indirectly in the present chapter (p. 403).

Of the material available for a detailed comparison of the
spinal cord of the Hominidae with those of their congeners and
other mammals, the exhaustive essay by Waldeyer on the spinal
cord of the Gorilla is by far the most instructive1. While arriving
at the general conclusion that in its main features, including its
histological structure, the spinal cord of the Gorilla so nearly
resembles that of the Hominidae that for the purposes of com-
parison with the lower Eutheria the one cord would serve
practically as well as the other, Waldeyer notes the following
points as of prime importance among those brought to light in
the course of his investigations.

The spinal cord of Man is most closely approached by that of
the Gorilla, not only in its outward form and proportion, but also
in the microscopical appearance of the transverse sections. The

1 Abhand. der Akad. der Wiss. Berlin, 1888, in. pp. 1 — 147 ; Univ. Lib.
Camb. 21. 5. 76.

416

THE COMPARATIVE MORPHOLOGY [SECT. C

human cord is however stouter and apparently relatively shorter
in the thoracic region.

In absolute bulk, however, the cord in the Hominidae is the
greater (the comparison was instituted between individuals of
approximately similar age). The contrast is marked even in the
cervical region, and is the more striking, since the upper ex-
tremities of the Gorilla being more precocious in development, and
attaining finally a higher degree of specialisation (in certain respects)
than those of Man, would seem to demand an increased supply of
nerve fibres which we might reasonably expect to see represented
by a cervical enlargement of great size. But the superiority of the
human cord in this respect throws the observer back on the con-
sideration that the number of fibres, and the consequent size of
the cervical enlargement of Man, are expressive of the large
number of fibres supplied by the brain in anticipation of the
future development of “ skilled movements.”

In actual shape when viewed in transverse section, the human
cord differs from that of the Gorilla, the maximum transverse
diameter in Man passing through the central canal, and the
contour being more rounded than in the Gorilla, in which the
maximum transverse diameter will be found to fall anteriorly to
the central canal. Finally, the lateral cornua of the grey matter
of this (cervical) region are more pronounced in the human cord.

In the thoracic region (besides the feature already mentioned)
the appearance in transverse sections is instructive. In Man both
cornua of grey matter are more slender and run out further from
the central canal than in Gorilla. In the latter the posterior
cornua have a particularly truncated aspect in comparison with
those of Man, the intermediate grey matter also extending further
from the centre of the cord than in the latter. In this respect the
cord of the Orang-utan presents appearances closely resembling
those of the cord of the Gorilla1.

On the other hand, the nucleus dorsalis (Stilling) presents
differences of conformation and position : in Man, it is situated at
the inner margin of the posterior horn of the grey matter, and
presents an elliptical contour, the long axis of which is approxi-
mately sagittal in direction. In the Gorilla the nucleus is much
1 Cf. Rudolph Fick, Abhand. cler Alcad. Berlin, 1899 — 1900, p. 36.

CHAP. XV] OF THE SPINAL CORD 417

nearer the central canal ; it is elliptical in contour, and the long
axis is more nearly transverse than coronal in direction. It is
noteworthy that Pick (quoted by Waldeyer, op. cit. v. p. 415 supra)
has recorded an example of a human cord in which the nucleus
dorsalis resembles that of the Gorilla in respect of the above features.

Again, Clarke’s column (represented in section by the nucleus
dorsalis) in the Hominidae is closely approached by that of the
Gorilla. On this subject the well-known work of Mott1 on the
comparison of the spinal cords of Man, a Macaque and a Dog may
be cited. In Man, the cord is distinguished by the concentration
of the cells of the column of Clarke, at the lower thoracic and
upper lumbar region. In the lower forms of mammals just
mentioned (Macacus monkey and Dog), the column is more evenly
distributed throughout the dorsal region and upper lumbar region2.
The exact significance of the contrast between the Hominidae and
these lower mammals has so far merely been surmised. The exact
connections of the cells of the column, though long suspected and
for some time partly known (so far as their relation to the viscera
are concerned), have only been recently (so far as their cerebellar
relations are in question) completely demonstrated3. The surmise
in question, is that of Ferrier to the effect that the system may be
developed in relation to the erect attitude and equilibration, in
view of the association of the viscera and of the cerebellum with
these functions.

It must be added that Waldeyer detected in the cord of
Gorilla, an indication of its intermediate position, inasmuch as the
arrangement of Clarke’s column, though more like that of Man
than that of the Cercopithecidae, did not present the human
characteristic, viz., the lumbar development of that column, in its
highest degree.

Passing from the comparison of the spinal cord of the
Hominidae with those of lower Eutheria in general, to the
comparison with the Simiidae in particular, the only evidence at
present accessible is that provided by H. Virchow4 on the comparison

1 J. A. and P. Vol. xxn.

2 Cf. Mott’s figures, op. cit. p. 483.

3 Cf. Laura, quoted by Barker, The Central Nervous System, p. 584.

4 Anat. Anz. 1888, No. 18, p. 509.

D. M.

418

EMBRYOLOGY OF THE CEREBRUM

[SECT. C

of the cords of the various forms of the Simiidae. The result of that
comparison is to shew that Man is most closely resembled by the
Gorilla, which in turn is more closely allied to the Hominidae
than to the Chimpanzee, a surprising result which certainly
requires confirmation from the evidence of several examples.
Next to the Chimpanzee comes the Orang-utan, while all three
apes are (like the Hominidae) very distinct from Hylobates.
Rudolf Fick1 has pointed out several features in which the cords
of the Gorilla and Orang-utan agree (op. cit. pp. 35, 36) ; the same
author has made elaborate observations on the histology of the
neuroglia in the cords of Cebidae, Cercopithecidae, and Simiidae,
and promises the publication of his recent researches by the
method of staining with methylene-blue (intra vitam). From the
evidence of comparative morphology, the association of the
Hominidae in a natural order with the other Primates, and
especially with the Simiidae, is thus seen to be confirmed.

II. Embryology. The embryological evidence of the brain
of the Hominidae points in the same direction as that of com-
parative morphology, though, as has already been remarked, the
details of evidence are wanting. We have seen that so early
as the seventh week of embryonic life, the human brain begins to
surpass that of the Simiidae in size, nor will this early difference
be a matter of surprise, in view of the difference in bulk which dis-
tinguishes the organs at the completion of growth. 3 here remain
but a few points for special mention in this connection. In the
first place, the connection of the olfactory tract and pyriform lobe
may be seen in the brain of the human embryo at the fifth month
as clearly as in any of the Lemuroidea. (Cf. Fig. 237.)

Secondly, the ontogenetic development of the corpus callosum,
in succession to the earlier dorsal commissure, has been demon-
strated. (Cf. Mihalkovics and Marchand, quoted by Minot, Human
Embryology, p. 683.)

Elliott Smith2 notes that the supra-callosal part of the hippo-
campus major is visible in the brain of the human foetus at the
7th month (cf. Fig. 242). The same author has recorded3 a case

1 Abhand. der Akademie, Berlin, 1899—1900.

2 Cat. Mas. Roy. Coll. Surg., London, 1903.

3 J. A. and V. Vol. xxxviii, p. 158.

419

CHAP. XV] EMBRYOLOGY OF THE CEREBRUM

in which the normal condition of the insula (exposed anteriorly, and
limited by a fronto-orbital sulcus) in the Simiidae, is exactly re-
produced in a human foetus (Egyptian) of about 8 months. Elliott
Smith remarks however that such an exact reproduction is very
rare.

Stria larjcisii

Fig. 242. Mesial aspect of the right hemisphere of the brain in a human
foetus at the sixth month : shewing the supra-callosal part of the hippocampus as
the stria lancisii.

Thirdly, the effects of the increased extent of the neo-
pallium, in the direction of producing furrows and convolutions
upon its surface, is generally admitted, and has formed the subject
of numerous memoirs, of which that of Cunningham1 is of especial
value.

The balance of opinion now ascribes the so-called “ transitory
fissures” (which have been observed on the surface of the hemi-
spheres of embryos of the third to fourth months, though they are
subsequently lost) to the results of imperfect preservation of the
specimens ; these fissures possess consequently no morphological
value, and will not be further discussed in this place. It may
however be remarked, that there is not yet complete agreement of
opinion regarding certain fissures that have been thus observed,

27—2

1 Cunningham Memoir, vn.

420

RACIAL VARIATION IN THE CEREBRUM [SECT. C

and that Professors His and Hochstetter in particular, were in
disagreement on several points connected herewith1.

Some other data relative to the features of the encephalon in
the Hominidae at two different stages of intra-uterine development,
will be found in Chapter vi.

III. Racial Variation. We now come to the variations of
the encephalon found within the limits of the Hominidae, and
must first of all remark that in addition to the study of the actual
conformation of the organ, evidence of a comparative nature has
been sought in the study of the weights, either of the whole
encephalon, or of its constituent parts.

The space available does not admit of a discussion of the results
of observations on the brain-weights of the Hominidae and other
Primates, and a further excuse for this deficiency may be found in
the plea that the primary object in view is the discussion of
morphological conformation, of which weight is but a vague and
indefinite function. This method of investigating the differences
between animal forms is none the less valuable. As regards the
Hominidae, reference may be made to numerous tables and charts,
in Donaldson’s Growth of the Brain (in the Contemporary Science
Sei'ies), to Thane’s records (in Quain’s Anatomy, Vol. ill. Part I.),
and to the statistics recently published by Marchand and Bolk2.

In addition to these, the following notes may be appended
here. The great cerebral development of the Hominidae will be ^
surely demonstrated by the weight of the brain, whether in com-
parison with that of the spinal cord, or that of the whole body. It may
be noted that the brain weight of the (white) Hominidae is about
Tjuth part of the total body weight, and this ratio affords an instructive ,
means of comparison between the Hominidae and other animals, j
in an adult Gorilla for instance the ratio is ^ approximately.

But it is noteworthy that while the higher Primates dififei j
markedly herein from the Hominidae, the (lower) Cebidae, such as K

1 Cf. His, Die erste Entwickelung das menschliehen Gehirns, Leipzig, 1904. I
Hochstetter, Beitrdge zur Ent. den Gehirns. Bibliotheca medico., 1898. Goldstein, ,
Archiv fiir Anatomie und Physiologic, 1903, Auat. Abth. : also Amt. Am. Bund j

xxiv. No. 22, pp. 529 et seq. __ j

2 Abhand. der kbn. Sachs. Gcs. der Wissenschaften, xxvi. Matli.-phys. Kl. xxvii. j

1902. Bolk (Petrus Camper, Di. n. AH. 4).

421

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

Chrysothrix or the Hapalidae, more nearly approach the Hominidae
in this respect. Numerous data are given, and their significance
fully discussed by Dubois in the paper already quoted in this
chapter (p. 401, footnote).

It will he evident in the next place, that in the search for data
regarding the various human races, great lacunae remain to be
filled so far as the more primitive of these are concerned. In the
absence of actual brains, this has led to various attempts to infer
the brain-weight from the corresponding cranial capacity, and the
method of arriving at the most correct estimate of the latter
quantity has been indicated in a preceding Chapter, XI. (p. 274); the
employment of such a method is of course absolutely necessary in
the case of fossil specimens, whether human or other.

Manouvrier1 shewed that the brain-weight is approximately
obtained, when the value (in c.c.) of the cranial capacity is multiplied
by the coefficient -87. Thus the equation may be represented as
W (brain-weight in gm.) = C (cranial capacity in c.c.) x -87 or

W = C x x.

But the relation of the two quantities is not really so simple :
as in the case of the stature in relation to the limb-bones (cf.
p. 342), the more correct equation is of the form

W = C x x + x'.

Evidently, then, the coefficient is a variable one, and the value
•87 quoted by Manouvrier is but an average value. Welcker2 has
given several values for the coefficient, and the subject has been
recently and fully discussed by Lee3.

It may be pointed out, however, that while in virtue of superior
weight of brain, whether this be absolute, or relative to his body
weight, the Hominidae stand in a position of great eminence
among the Eutheria, yet at the same time, there is no definite
evidence that within the Hominidae, excessive brain-weight im-
plies, or need be accompanied by, high intellectual ability. So
that neither brain-weight nor cranial capacity, nor the dimensions

1 MSm. de la Soc. d’A. de Paris, 2° ser. t. hi. 1885, quoted by Thane in Quain's
Anatomy, Vol. n., Part 1.

2 Arch, fiir Anth. xvi. 51, quoted by Thane.

3 Phil. Trans. 196 A. 1901.

422

RACIAL VARIATION IN THE CEREBRUM [SECT. C

of the head whence the foregoing may be inferred are directly
useful as aids to assessing mental attainments.

Turning next to the spinal cord. Here we find, in the weight
(whether absolute or relative) of the cord, evidence which demon-
strates the exalted position of the Hominidae among the Primates.
For the Hominidae, data are available in the published researches of
Pfister1 who has compared in many cases the weight of the human
cord with the body weight. The final and characteristic propor-
tion between the two would seem to be attained in the course of
the first year of life.

Lastly, the corresponding comparison, or the comparison of the
weights of the brain and the cord respectively, may be made with
the aid of the method proposed by J. Ranke (and already described,
Chapter XI. p. 277) of determining the capacity of the vertebral canal.
Ranke’s chief results have been indicated in the connection just
mentioned, i.e. in connection with the osteometric section of this
book, within which the method more properly falls.

Our attention must now be turned, as before, to the conforma-
tion of the brain, to which, as to other organs, strictly morphological
considerations apply.

(1) The influence of age must be first reviewed. In the child
at birth the human characteristics of the brain are already manifest,
and have nearly attained their highest point of development. The
central lobe is not in all cases completely overlapped by the
opercula, but the rhinencephalon is much reduced, and the neo-
pallium is marked by all the more important furrows which
characterise the adult organ. Growth in absolute size is complete
soon after the ninth year, at an epoch at which the general growth
of the body is still far from completion.

(2) If the sexes be compared, no constant difference can be
demonstrated between them, conferring upon either a morphological
status superior to that of the other.

(3) In the various races of the Hominidae, one would expect
some modification to be associated with the form of the brain,
as shewn by the skull-form ; ex. gr. it would not excite surprise
if the arrangement of furrows and convolutions were found to be
grouped in a different and characteristic manner in long-headed

1 Neurol. Centralbl. Band xxii.

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM 423

and short-headed individuals respectively. But although Schafer1
states that in the cerebral hemispheres of brachycephalic indi-
viduals, a tendency is manifested to the production of transverse
divisions (in the convolutions), which is not shewn in the hemispheres
of the brains of dolichocephalic individuals, yet it must be said
that detailed evidence upon this subject has yet to be provided.

The cerebral characters of several representatives of the so-
called “ lower ” races are now on record, but hitherto it has not
been possible to arrive at any general conclusions regarding these,
because of the lack of a conventional system of enquiry, and indeed
of a consensus of opinion as to the special points that require
investigation, and are the most likely to provide information
which will determine the status of the specimen subjected to
the research.

The difficulties of arriving at a general statement, which shall
even approximately sum up the details of conformation in any one
of these cases, are so great that observations have here been
restricted to determining as far as possible the characteristic
features in each group, of the following structures ; (a) the rhinen-
cephalon, (b) the central lobe or insula, and its more immediate
surroundings, (c) the sulcus lunatus (or representative of the
Affenspalte). Several brains in the Anatomy Museum at Cam-
bridge have been examined, and reference has been made to
figures published in illustration of various memoirs. The results
of these observations have been appended in a series of brief
notes. In the present connection, the greater depth and dis-
tinctness of the rhinal fissure, the slighter tortuosity of the
neopallial cortical folds, and the greater frequency of the retention
of an occipital operculum and a sulcus lunatus, are points of prime
importance, denoting the inferiority of the brains in which they
occur2.

Australian Aborigines. Four brains of aborigines of Australia
(cf. Figs. 243, 244, 245, 246) are in the University Museum of
Anatomy at Cambridge. The brains are all small, as indeed

1 Cf. Quain’s Anatomy, Vol. ni. Part I.

2 The most complete bibliography of the comparative anatomy of the brain
in the Hominidae is that given by Spitzka in the American Journal of Anatomy,
Vol. ii. 1903, p. 68.

424

RACIAL VARIATION IN THE CEREBRUM

[SECT. C

IS to be expected in the case of individuals of such small (average)
cranial capacity as these natives.

Fig. 243. Right cerebral hemisphere of an aboriginal of Australia (Mus,
Anat. Cant. W.L.H.D. photo.).

Fig. 244. Left cerebral hemisphere of an aboriginal of Australia (Mus.
Anat. Cant. W.L.H.D. photo.).

The parts connected with the rhinencephalon provide material
for the following observations. In specimen No. 1 (Fig. 243),
the rhinal fissure is distinct and boldly curved (cf. Elliott Smith’s
comments on this feature, J. A. and P. 1903, Nov.); in No. 2
(Fig. 244), the rhinal fissure is confluent with the collateral fissure;
in No. 3 (Fig. 245), the rhinal fissure is distinct and the fasciola
grisea (gyrus Andreae Retzii) is also well seen: the foregoing

425

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

remarks apply to both hemispheres of Nos. 1, 2, and 3; in the
right hemisphere of No. 3, the diagonal band of Broca is very

Fig. 245. Left cerebral hemisphere of an aboriginal of Australia ( Mus .
Anat^ Cant. W.L.H.D. photo.).

Fig. 246. Right cerebral hemisphere of an aboriginal of Australia (Mus.
Anat. Cant. W.L.H.D. photo.).

clearly seen, posteriorly to the anterior perforated space. In
No. 4 (Fig. 246) the fasciola grisea is large on the right side :
in the left hemisphere it has not been preserved : the gyrus
subcallosus is distinct on each side, and the rhinal fissure is boldly
curved.

The cerebral convolutions1 are less tortuous than in the (larger)

1 References to literature :

Rolleston, Joum. Antlir. Institute, 1887.

Miklucho-Maclay, Proc. Linn. Soc. N.S. Wales, Vol. vm.

Karplus, Obersteiner’s Arbeitcn, 1902.

426

RACIAL VARIATION IN THE CEREBRUM [SECT. C

brains of white men : of the four brains here considered, two are
characterised by the incomplete submergence of the insula, since
the opercula (especially the frontal operculum) are less exuberant
than in the brain No. 4, in which the insula is not exposed. In
all cases, however, all the opercula exist. One specimen (No. 1) is
not sufficiently well preserved to supply definite evidence.

Particular attention was given to the occipital poles of these
hemispheres, and in four out of the eight hemispheres the sulcus
lunatus was recognised. (Figs. 247 — 254 inch Also cf. Fig. 34.)

The detailed descriptions may commence with that of the specimen dis-
tinguished as No. 2 in the Museum Catalogue. As will he seen from the
outline drawings, both hemispheres of this brain present a well-marked
sulcus lunatus, bounding the remnant of the occipital operculum. Con-

Fig 247 Right cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn (Mm. Aunt. Cant. No. 2 W.L.H.D. del.). In this and the
following figures S. luii. denotes the Sulcus lunatus.

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

427

sidering the right hemisphere (Fig. 247) first, the following characters are
noteworthy :

(1) The representative of the sulcus occipitalis transversus terminates
beneath the operculum.

(2) The sulcus paramesialis is independent of the sulcus lunatus.

(3) The latter sulcus gives off a small branch — the sulcus praelunatus.

(4) Superior and inferior occipital sulci are present.

Turning now to the left hemisphere (Figs. 244 and 248), the occipital
operculum is seen with even greater distinctness : the following points are
also noteworthy.

Fig. 248. Left cerebral hemisphere of an aboriginal of Australia. The occipital
convolutions are shewn (Mm. Anat. Cant. No. 2. W.L.H.D. del.).

(1) The sulcus occipitalis transversus terminates in the sulcus lunatus,
beneath its opercular lip.

(2) The sulcus paramesialis is independent of the sulcus lunatus.

(3) The sulcus praelunatus is present, and confluent with the sulcus
lunatus.

(4) Sulci occipitales superior and inferior arc present, but confluent
anteriorly.

Specimen No. 2 thus affords an excellent illustration of the occurrence of
the occipital operculum in the brain of Man.

428

RACIAL VARIATION IN THE CEREBRUM [SECT. C

When we turn to specimen No. 3 (of the Cambridge Museum Catalogue)
we find an equally good illustration of the condition in point.

The occipital end of the right hemisphere of No. 3 (cf. Fig. 249) has
suffered some damage, and the appearances are, in consequence, not easy to
interpret. It would seem as though the sulcus lnnatus ( S . lun.) were interrupted
by a small gyrus emergent from its depth, so that the sulcus is divided into
a mesial portion, whence a sulcus paramesialis arises, and a more lateral
portion, giving off a sulcus praelunatus. If the foregoing interpretation is
correct the sulcus occipitalis transversus just reaches the margin of the
sulcus lunatus. The sulcus occipitalis superior is present in its typical form ;
and the sulcus occipitalis inferior is distinct and isolated.

Fig. 249. Right cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn (Mus. Anat. Cant. No. 3. W.L.H.D. del.).

With regard to the left hemisphere (Figs. 245 and 250), the occipital
operculum is very distinctly seen (as has been said) : the condition closely
resembles that figured by 1.11 iott Smith ( .1 nut. Anzeigcv, Bd. xxiv. Fig. 1)
in the brain of an Egyptian Fellah. The following points may further be
remarked :

(1) The sulcus occipitalis transversus just fails to reach the sulcus
lunatus.

(2) The sulcus paramesialis takes origin from the sulcus lunatus. (Cf.
Elliott Smith, op. tit. Fig. 1.)

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

429

Fig. 250. Left cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn (Mus. Anat. Cant. No. 3. W.L.H.D. del.).

Fig. 251. Right cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn (Mm. Anal. Cant. No. 4. W.L.H.D. del.).

430

RACIAL VARIATION IN THE CEREBRUM [SECT. C

(3) A sulcus praelunatus arises from the sulcus lunatus (Elliott Smith,
op. cit. “a,” Fig. 1).

(4) Superior and inferior occipital sulci are present, and independent.
The former has the typical “Y” shape of the corresponding sulcus in the
Anthropoidea.

In the right hemisphere of Brain No. 4 (Figs. 246 and 251), the appearances
are not very clear, but somewhat resemble those of the last-described right
hemisphere. As the correct interpretation, it is submitted that the sulcus
lunatus ( S . lun.) is interrupted, and that moreover the inferior occipital sulcus is
very deep and opercular, overlapping the convolution on its lateral aspect, and
thus compensating for the feeble operculation in the typical situation.
According to this interpretation the following remarks are relevant :

(1) The sulcus occipitalis transversus just reaches the lateral constituent
into which the sulcus lunatus has been resolved by the emergent gyrus.

(2) The mesial component of the sulcus lunatus gives off a sulcus
paramesialis.

(3) The lateral component of the sulcus lunatus gives off a sulcus prae-
lunatus.

(4) Superior, accessory, and inferior occipital sulci are present, the latter
being very large and almost confluent with the parallel sulcus.

Turning to the left hemisphere of Brain No. 4 (Fig. 252), we again find a
lack of definite information as to the identity of the several sulci, and again

S.iDWpa^[“6;

S.occ.irjJ. S.occ.Sup.

Fig. 252. Left cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn (Mus. Anat. Cant . No. 4. W.L.H.D. del.).

431

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

find a deep and operculated sulcus, which may be either part of the sulcus
lunatus, or may represent the inferior occipital sulcus.

Brain No. 1 (of the Museum Catalogue) is much inferior to the other
three in preservation, and the appearances are therefore more difficult
to interpret than in the better-preserved examples. The right hemisphere
(Figs. 243 and 253) may be first considered : it is not possible to recognise

Fig. 253. Right cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn (Mus. Anat. Cant. No. 1. W.L.H.D. del.).

either a definite operculum, or a continuous sulcus lunatus : the condition
resembles that represented in Fig. 5 of Elliott Smith’s paper (Anat. Anz. loc. cit.).
The interpretation and the identity of the several sulci are indicated in the
diagram (Fig. 253) ; the sulcus paramesialis appears to be present : close
to it, part (S. lun.) of the sulcus lunatus seems to be combined with a superior
occipital sulcus, while a long and almost rectilinear sulcus, more laterally placed
(? S. lun.) looks like the un- operculated lateral part of the sulcus lunatus
together with its offshoot, the sulcus praelunatus. It will be noticed that
the intraparietal sulcus is not bifurcated terminally as the sulcus occipitalis
transversus.

Turning to the left hemisphere (Fig. 254), the appearances are more
definite: for there is a distinct (though small) operculated sulcus lunatus:

432

RACIAL VARIATION IN THE CEREBRUM

[SECT. C

this is joined by the sulcus occipitalis transversus: no distinct sulcus para-
mesiahs is seen, and no sulcus praelunatus is present : the inferior occipital
sulcus is very distinct, but the sulcus occipitalis superior on the contrary
is obscure. J

Fig. 254. Left cerebral hemisphere of an aboriginal Australian. The occipital
convolutions are shewn [Mm. Anat. Cant. No. 1. W.L.H.D. del.).

It thus appears that in four out of these eight cerebral
hemispheres of aborigines of Australia, a distinct occipital oper-
culum is seen : in the remaining four hemispheres, the appearances
are not so definite, nor can they be further classified. The sulcus
lunatus is said by Elliott Smith to be present in the brain of the
aboriginal Australian described by Karpins (in Obersteiner’s
Arbeiten, 1902)1. The lowly status of these aborigines is hereby
clearly shown. Two points must be mentioned in conclusion;

(i) the deepening of the inferior occipital sulcus, where the occipital
operculum has disappeared, may be compensatory in nature ; and

(ii) the smallest brain of the four does not, as might have been
expected, present the best example of an occipital operculum.

1 The contention that the Affenspalte must bound an occipital operculum,
beneath which are received the terminations of the intraparietal and internal
parieto-occipital sulci, is hardly justified; and the Simiidae would be deprived
of this cerebral feature were the condition to be insisted upon.

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

433

Cerebellum. In one aboriginal Australian brain in the Cam-
bridge collection, the cerebellum has been preserved, and the
flocculi are not larger than those of the brain of the white races.

Brain weight. No data seem to be on record. Estimates may
be obtained from the value (in c.c.) of the cubical contents of the
cranium, but such results will be only approximations. Davis’
estimate1 was 1185 gm. (white men 1333 gm.). With the fore-
going, the brains of Papuans and aborigines of New Caledonia
should be associated. The only descriptions of Papuan brains are
those furnished by Huntington2.

A frican negroes.

Two brains of negroes are preserved in the Cambridge collec-
tion. They present the
following characters. The
rhinal fissure is as dis-
tinct and boldly curved
as that recorded in the
brain of an Egyptian Fel-
lah3 (No. 2, cf. Fig. 257) ;
it is short and straight,
while deep, in No. 1; the
uncus in No. 2 is much
recurved and resembles
the uncus in Hylobates4.

In both brains the fasciola
grisea (gyrus A. Retzii) is
distinct. In both brains
the insula is practically
quite submerged (cf. Fig.

255). In three out of the four hemispheres, the sulcus lunatus
is present (the remaining hemisphere has been mutilated locally,
so as to render the identification of this feature impossible).
Elliott Smith has observed this sulcus in the brains of Soudanese

Cf. Thane, Quain 8 Anat. Vol. iii. Pt. I. p. 180. The sulcus lunatus is absent
from two brains of natives of New Caledonia at Paris (Mas. d’Hist. Nat.).

2 American Journal of Anatomy, Vol. i. p. 517.

3 Elliott Smith, Journ. A. and P. xxxvii. p. 325.

Cf. Zuckerkandl, Zeitsch. filr Morph, und Anthrop. Bd. iv.

D. M.

Fig. 255. Part of the left hemisphere of the
cerebrum of a negro (No. 2) in' the Cambridge
Anatomical Collection. 1. Insula: almost com-
pletely submerged. The space left superficially to
the insula was occupied by the pia mater and
blood-vessels. F. frontal lobe, T. temporal lobe.

434

RACIAL VARIATION IN THE CEREBRUM [SECT. C

negroes. The flocculus in the negro brain does not seem appreci-
ably larger than in the brain of the white man.

The accompanying figures (256, 257) shew the difference in the
form of the uncus in the two negro brains; in No. 2 (Fig. 257),
the remarkable mode of termination of the calcarine sulcus is
noteworthy for it turns outwards, not inwards.

Fig. 256. Part of the mesial surface of the right cerebral hemisphere of a
negro (No. 1). The Gyrus A. lietzii and the Uncus are shewn. The Fissura rhinalis
(F. rhin.) is not unusually distinct as compared with the condition in the European
brain. Spl. Splenium corporis callosi. G.A.R. Gyrus A. Retzii. F. rhin.
Fissura rhinalis. Temp. lobe. Pole of the temporal lobe. (W.L.H.D. del.)

The brain of a young Zulu (cf. Fig. 258) bears a sulcus lunatus
in each hemisphere. This brain is not described in detail, in
the catalogue in which it is recorded1. The appearance of the
occipital lobes is represented in the accompanying diagram
(Fig. 258).

In addition to the foregoing observations, I have collected the
following references to the literature of the negro brain, and append
some notes upon the same.

1 Elliott Smith, Cat. Mus. Hoy. Coll. Surg. Vol. n.

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

435

Fig. 257. Part of the mesial aspect of a negro brain (No. 2). The Fissura
rhinalis (Fiss. rhin.) is very distinct. Spl. Splenium corporis callosi. G.A.li.
Gyrus A. Retzii. Fiss. rhin. Fissura rhinalis. Temp. lobe. Pole of the
temporal lobe. (W.L.H.D. del.)

Fig. 258. The sulcus lunatus is shewn in each cerebral hemisphere of a young
Zulu. (Mm. Roy. Coll. Surg.)

Waldeyer1 provides notes on twelve negro brains from German
East Africa: the weights are recorded. Waldeyer points out that
secondary convolutions are well developed; that the cuneus, pre-

1 Waldeyer, Sitz. d. k. Ak. d. I Fiss, Berlin, 1894 (Camb. Univ. Lib. Class 17-4-1,
etc.). Many references given.

28—2

436

RACIAL VARIATION IN THE CEREBRUM [SECT. C

cuneus, and lobulus paracentralis present no distinctive features ;
that the “ parieto-occipital sulcus ” is extensive on the lateral
cerebral surface, but no identification vvitli the Affenspalte is
attempted. As a rare anomaly, the occurrence of the confluence of
the sulcus olfactorius with the sulcus fronto-marginalis (Wernicke)
is recorded.

Waldeyer’s figures yield no sure information as to the presence
or absence of the sulcus lunatus.

As regards the brain-weights : the average is 1148 gm. (the
weights were recorded in the fresh state) for 12 brains. Waldeyer
quotes the figures of Topinard, 1234 gm. (range, 1445 gm. to
974 gm.) for 40 examples; and American records (War of Secession),
as 1331 gm. for 121 cases.

Broca’s work1 does not give specific information as to the
features of the rhinencephalon, or the occurrence of the sulcus
lunatus or its representative.

Parker'2 3 represents (op. cit. Plate xxxvi.) the left hemisphere of
the brain of a mulatto, with a sulcus lunatus (which seems to be
described as the first occipital sulcus). The same sulcus is seen
in negro brains represented (Plates xli. and xlii.) in the same
work.

Arkin8 describes an Ashanti brain ; the insula is submerged in
this example.

Fallot4 * 6 provides no very important data.

Calori8 describes the brain of a negro from the Guinea coast.
The sulcus lunatus is represented (but not recognised or specifically
described) in each hemisphere : the fasciola grisea is very distinct
in this brain : so is the gyrus subcallosus, and the rhinal fissure is
deep, and boldly curved.

Herve8, in giving brief accounts of the convolution of Broca in
seven brains of negroes, points out the comparative lack of

1 Broca, Memoir, 1888 (Camb. Univ. Lib. i. 13. 17).

2 Parker, Journ. Ac. Nat. Sci. Philadelphia (Camb. Univ. Lib. MA. G4. 10), also
Proc. Philad. Ac. 1878 (Univ. Lib. MC. 10. 30).

3 Arkin, Neurologisclies Centralblatt, 1899, p. 741. An abstract of the Russian
memoir.

4 Fallot, L’Anthropolofiie, 1890, p. 056.

6 Calori, Mem. della. Ac. di Biol. Ser. n. Tom. v. 1805, p. 177.

6 Herve, La circonvolution de Broca, Paris, 1888.

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM 437

tortuosity of this convolution, with the consequently rare ap-
pearance of three anterior limbs of the fissure of Sylvius.

White and Yellow races of Europe, Asia, and America.

(a) The cerebral hemispheres of a Bengali native of India,
and a Tamil, are thus characterised : in all four hemispheres
the rhinal fissure presents no peculiarities and the central lobe is
submerged : in three of the hemispheres a representative of the
sulcus lunatus is seen, but in the fourth, the cortex has been
locally destroyed in removing the brain (cf. Figs. 259, 260, and
261). Reference must here be made to Kaes’ work on a Hindu
brain ( v . infra, p. 440).

Fig. 259. Right cerebral hemisphere of a Bengali. The occipital convolutions
are shewn. (Mug. Anat. Gant. W.L.H.D. del.)

( b ) Brains of Chinese : three brains are in the Cambridge
Museum : two of these are of considerable size, the third being
slightly below the average size of the European brain. In four
hemispheres the conformation of the rhinencephalon (so far as can
be judged from macroscopic examination) does not differ from its
appearance in the white races ; in all six hemispheres the central
lobe (insula) is submerged. In five hemispheres, the sulcus lunatus

438

RACIAL VARIATION IN THE CEREBRUM

[SECT. C

Fig. 260. Left cerebral hemisphere of a Bengali. The occipital convolutions
are shewn. (Mus. Anat. Cant. W.L.H.D. del.)

Fig. 261.
are shewn.

es.

Left cerebral hemisphere of a Tamil. The occipital convolutions
(Mus. Anat. Cant. W.L.H.D. del.)

439

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

was detected (cf. Fig. 262), though it was absent from the sixth
hemisphere.

S. pa''-

Fig. 262. Right cerebral hemisphere of a Chinaman from Singapore. The
occipital convolutions are shewn. ( Mus . Anat. Cant. W.L.H.D. del.)

The ensuing notes refer to some of the existing literature on
the Chinese brain. Benedikt1 has described three Chinese brains,
but his illustrations are so indistinct that no certain information
can be gathered from them, except that the cortex is richly con-
voluted. In the illustration provided by Hatch2, no definite sulcus
lunatus can be detected. Dercum’s3 paper is not accessible to me.
Clapham4 shewed that the average brain weight in sixteen Chinese
exceeded the average brain weight in Europeans : in four Pelew
Islanders, the brain weight on the average exceeded that of
Europeans. In Chinese and Pelew Islander brains alike, the
convolutions were less tortuous than in brains of white races, and
the Pelew brains are also characterised by the symmetry of the
two hemispheres (a sinian feature).

1 Benedikt, Med. Jahrbuch. Neue Folge, 1887, p. 121.

2 Hatch, Jnternat. Monatsschr. fur An. und Pliys. 1891 (Band viii.). (Camb.
Univ. Lib. i. 14. 8.)

3 Dercum, Jourti. Nerv. & Merit. Die. 1889.

4 Clapham, Journ. Anthrop. Instit. 1878.

440 RACIAL VARIATION IN THE CEREBRUM [SECT. C

Kaes1 investigated the histology of the cortex in German,
Hindu, and Chinese brains respectively. Variations in the relative
amounts of the projection and association fibres were found, the
former predominating in the Hindu, the latter in the German brain.

(c) Fuegians: Manouvrier2 and Seitz3 have described brains of
Fuegians, the total number being three. In Manouvrier’s example
there seems to have been a sulcus lunatus in the left, but not in
the right hemisphere. In none of the four hemispheres figured
by Seitz is this sulcus recognisable. In complexity of convolutions,
these brains are not markedly inferior to those of white men.

( d ) The brain of a Laplander described by Retzius4 presents
no striking deviation from the brains of other Europeans.

(e) Among the white races, the brain has been specially
studied among the Letts, by Weinberg3.

(/) Two brains labelled “ American races,” are in the Paris
Collection ( Mus.d’Hist . Nat.)] the left hemisphere of the larger
specimen, bears an unusually distinct sulcus lunatus. Possibly
the brain is that of the Fuegian described by Manouvrier (cf.
Section (c) supra).

The Polynesian race.

The brain of a native of the Marquesas islands was examined
by Manouvrier who reports8 that the complexity of the cerebral
convolutions was less than in the average brain of white men.
The sulcus lunatus is very distinct in the left hemisphere of a
Polynesian brain (a cast) at Paris ( Mas . d’TIist. Nat.).

The Greenland or Eskimo race.

Six brains of Eskimo have been examined. The earliest data
are provided by Chudzinski7, then come the accounts given by
Hrdlicka8, and those published by Spitzka".

1 Kaes, Neurol. Gentralblatt, 1895, p. 889, also Arch. fUr Psychiatric. Bd. xxv.
p. 698.

2 Manouvrier, Bull, de la Soc. d’A. de Paris, 1894, p. 895.

3 Seitz, Zeitsch. fiir Ethn. Band xvm. (Camb. Univ. Lib. MH. 34. 44.)

4 Retzius, Virchow's Festschrift. (Camb. Univ. Lib. ix. 9. 4.)

5 Weinberg, Das Gehirn der Letten. 8 Bull, de la Soc. d’Anth. dc Paris, 1892.

7 Bull, dc la Soc. d'A. de Paris, 1881. (Camb. Univ. Lib. MC. 3. 52.) Seo also

Hervd ; La circonvolution de Broca, 1888.

8 Proc. Am. Med. Psych. Assn. 1899. Also the Am. Anthropologist n. s. 3. 1901.

» Amer. Journ. of Anal. 1903. This paper contains a full bibliography.

441

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

Chudzinski pointed out the comparative simplicity of the
convolutions of the cerebral hemispheres at his disposal, but the
brain described by Hrdlicka does not indicate this as a general
feature of the brains of Greenlanders.

Spitzka’s material comprised two female and one male brain of
Eskimo from Smith’s Sound. As regards the conformation of the
basipallium and marginal pallium, and particularly the region
of the uncus, incisura temporalis, and gyrus A. Retzii (balken-
windung), Spitzka’s figures yield no precise information.

Two brains were characterised by a degree of complexity of
cortical convolutions in no way inferior to that found in white men.
It must be admitted however, that the insula was in one of these
specimens partially exposed. In the third brain, the convolutions
of the cerebrum were distinctly simpler than in the other two.
The difference in the accounts of Chudzinski and Hrdlicka is
thus explained, by the range of variation of the cerebral cortex.
Spitzka suggests that the simplicity of the convolutions of the
third specimen (“ Avia ”) is explicable in view of the youth of the
individual, a girl of twelve years of age. But this explanation is
not wholly satisfactory, for by that age the maximum weight1, and
probably the highest degree of cortical complexity has been
attained in the white races.

As regards the sulcus lunatus, Spitzka’s figures provide material
for data relating to eight hemispheres, six of which are described
by that author, the remaining two being those of the Eskimo
brain described by Hrdlicka. In two out of the eight hemispheres
(viz. Fig. 5, op. cit. right hemisphere of “ Atana ” ( $ ), and Fig. 19,
op. cit. left hemisphere of “ Kishu,” the Eskimo described by
Hrdlicka) the sulcus lunatus can be identified.

Spitzka gives the average weight of the brain in three male
Eskimo as 1457 gm, and in four females as 1228-7 gm, values
in excess of the corresponding figures for European brains.

Bush race of S. Africa.

Gratiolet- figures the brain of the Bush-woman known as the
Hottentot Venus. In the illustration of this rather small brain no
evidence as to the conformation of the rhinencephalon is forth-

1 Donaldson, The Growth of the Brain, 1895.

2 Mtm. mr les plis cerebraux, 1854.

RACIAL VARIATION IN THE CEREBRUM [SECT. C

coming, and attention must be confined to the neopallium ; the
coitical convolutions are infantile, not possessing the same degree
of tortuosity as in adults of the white races, and they are not
unlike those of some infants at birth. In the right hemisphere
(op. cit. PI. 2, fig. 2) will be seen a distinct vestige of the sulcus
lunatus.

Fig. 2(53. The sulcus lunatus is shewn in each cerebral hemisphere of a Bush
native. (Mug. Roy. Coll. Surg.)

Fig. 264. The sulcus lunatus is shewn in each cerebral hemisphere of a Bush
native. (Mug. Roy. Coll. Surg.)

Two other brains of Bush natives were available for examina-
tion, viz. those in the Museum of the Royal College of Surgeons
(cf. Figs 263 and 264). Of these one is a female brain (Nos. 706
and 707, Cat. Mus. Roy. Coll. Surgeons, Phys. Ser. Part 2), and as
shewn in the accompanying sketch, the sulcus lunatus appears in
each hemisphere. The convolutions in general are infantile in
lacking the fulness of complexity usual in the white races. This
brain was described in detail by Marshall (Phil. Trans. No. 154,
1864). The brain of the Bush-woman dissected by Flower and
Murie (J. A. and P. Vol. 1.) whose account furnished data for
establishing many characters of the soft tissues in this type, was
handed to Marshall for description. But no description appeared,
nor does the brain appear to form part of the collection in the Royal

CHAP. XV] RACIAL VARIATION IN THE CEREBRUM

443

College of Surgeons. That collection does however possess the brain
of a Bushman (No. 708) presented by Professor Marshall, and one is
naturally led to suspect that there may be an error as to the sex,
and that this is the brain of the woman dissected by Flower and
Murie, a description of which is not forthcoming. However this
may be, the specimen 708, whether male or female, is furnished
with a sulcus lunatus in each hemisphere. Altogether then, the
sulcus lunatus is seen in five hemispheres out of the six subjected
to examination.

Riidinger is quoted by Herve, as giving an account of the brain
of a Hottentot in his Beitrag zur Anatomie des Sprach-Centrums :
p. 165. And Koch, quoted by Spitzka, described a Bush-woman’s
brain, in the Archiv fur Anthropologie, Bd. in., p. 307. Wyman
(. Boston Soc. Nat. Hist. Proc. ix., p. 56) described a “ Hottentot
Brain ” as weighing 3 lbs. 2 oz, which is not far removed from the
average weight of the brain in the European races. No details of
the conformation of this “ Hottentot ” brain are provided.

Before passing from this part of our subject, it remains to refer
very briefly to certain conditions which occur anomalously in the
brains of the Hominidae, and which claim attention and interest
in view of the foregoing statements as to the constituents of the
cerebrum.

We have seen that the basipallium or rhinencephalon is a
prime constituent of the mammalian cerebrum, and indeed of the
cerebrum in all vertebrates, save the very lowliest. Such conditions,
therefore, as are associated with imperfect development, or with
congenital absence of part or all of the rhinencephalon must there-
fore be of interest : and these cases constitute the first of the
groups to which reference will be made.

We have also seen that the development of the corpus callosum
is a grand characteristic of the neopallium of higher mammalia,
and that the fulness of development of that commissure-system is
distinctive of the Hominidae. What then, it will be asked, are the
features of the human brain in which the corpus callosum is (from
whatever cause, pathological or other) not developed? Cases of
congenital absence of the corpus callosum constitute the second
group to which reference will be made.

444 ANOMALOUS CONDITIONS OF THE CEREBRUM [SECT. C

Thirdly, we saw that exuberant production of gyri on the neo-
pallial sui'face was a second grand characteristic of the Hominidae
as of the higher Eutheria in general. What then, will be the
ai’rangement of gyri and sulci on the surface of a neopallium (of
Man), in which the inherent growth-force has proved insufficient
to reproduce the normal complex of surface-convolutions ? Such
instances make up the third group to which a glance must be
directed.

A. Congenital defects of all or part of the Rhinencephalon.

The condition is well illustrated by a case of the congenital
absence of the olfactory nerves in a human foetus (of about 8
months)1 (cf. Figs. 265 and 266). The posterior part of the

Fig. 265. Fig. 266.

Fig. 265. Eight cerebral hemisphere of a human foetus ; the olfactory nerves
are not present, and in the proportions of the hemispheres, the cerebrum resembles
that of Cetacea. ( Mus . Anat. Cant.)

Fig. 266. Mesial aspect of the left cerebral hemisphere of the same brain as
that represented in Fig. 265.

rhinencephalon is present, so are the corpus callosum and fornix.
The neopallium is less fully convoluted than normally, the insula
is exposed as in the Simiidae, and the form of the cerebral
hemispheres is very remarkable, the vertical diameter being much

1 By a fortunate chance, I had the opportunity of submitting this remarkable
specimen to Professors Retzius and Waldeyer, who agreed in at once remarking its
unmistakably cetacean appearance.

CHAP. XV] ANOMALOUS CONDITIONS OF THE CEREBRUM

445

increased, with concomitant lack of elongation antero-posteriorly.
This gives a peculiar spherical appearance to the cerebrum, all
the more noteworthy since this form is characteristic of the
Cetacean cerebrum, in which, as is well-known, the olfactory
nerves are normally absent, though, as in the above case, the
posterior parts of the rhinencephalon can still be recognised.

B. Congenital defect of the corpus callosum has been found in
association with various other malformations. Naturally the con-
dition in which there is no subdivision of the cerebrum into hemi-
spheres will first claim attention. An example of such an anomaly
of conformation is represented in Figs. 267 and 268, shewing two

Fig. 267.

Fig. 268.

Fig. 267. The conjoined cerebral hemispheres of a Cyclopian human monster
at the eighth month of foetal life. The upper aspect of the brain is shewn.

Fig. 268. Lateral view of the left aspect of the brain represented in Fig. 267
1, Optic thalamus; 2, Olive.

aspects of a brain in which no division of the cerebrum exists.
The specimen is the more interesting inasmuch as it was accom-
panied by apparent total absence of the rhinencephalon (for which
reason it might have been cited in the preceding category), and
the curious modification of the eyes and of the facial skeleton
known as Cyclopia.

Ihe chief features of this remarkable specimen are, the substi-
tution of a single practically non-convoluted mass for the two

446

ANOMALOUS CONDITIONS OF THE CEREBRUM [SECT. C

hemispheres ; absence of the corpus callosum, of the fornix, and of
the olfactory nerve ; fusion of the two optic nerves into a single
trunk.

It may be remarked that this is not an unusual conformation
of the brain in cyclopian monsters, and further that the disturbance
of development must have been experienced by the embryo at
a very early stage, for the two cerebral vesicles are distinct at the
commencement of the 5th week. (Cf. His. Die erste Entwickelung
cles menschlichen Gehirns. 1904, p. 6, Embryo KO.)

An instance of incomplete separation of the two hemispheres
was recorded by Turner1, and in this case the line of demarcation
was a mere longitudinal groove. The corpus callosum had failed
to appear, and there was but one ventricular cavity. The brain
was removed from an adult and convolutions were present, though
their arrangement was indistinct.

A good example of deficiency of the corpus callosum uncompli-
cated by lack of distinc-
tion between the two
cerebial hemispheres, is
recorded by Forel and
Onufrowicz2. The brain
was that of an adult (cf.

Fig. 269) and no part of
the corpus callosum can
be seen. Not only so, but
the forni x-com m issu re (the
psalterium, or original
dorsal commissure) is
equally undeveloped. On
the other hand the anterior
commissure, the fascia
dentata, the fimbria, the
body of the fornix, the uncus, and the g};rus A. Retzii are all
present3.

With regard to the neopallium, the chief point to notice is

Gytjipp

Fig. 2G9. Mesial aspect of a human cerebral
hemisphere in which the corpus callosum was
not developed (after Forel). The indications are
as follows :

Ca : Anterior commissure.

Ot : Optic thalamus.

Gy. hipp: Gyrus hippocampi.

Lt. Lamina terminalis.

CS. Calcarine sulcus.

1 J. A. and P. Vol. xii. 1878.

2 Tageblatt der Versammlung Dcutscher Naturforschcr in Salzburg, 1881.

3 Archiv fiir Psycliiatrie, 1887.

447

CHAP. XV] ANOMALOUS CONDITIONS OF THE CEREBRUM

the “ radial ” disposition of the neopallial sulci, which appear to
radiate from the optic thalamus (on the mesial aspect), or the
insula (on the lateral aspect). This point however has now but
an historical value. Before the true nature of the so-called
transitory fissures was known, their radial disposition was con-
sidered to be connected with the non-development of the corpus
callosum, which had not yet appeared in those early embryonic
brains : and this surmise was strengthened by the observation (just
quoted) of the radiation of sulci, in brains of which the corpus
callosum has not subsequently been developed.

The absence of a definite gyrus fornicatus is noteworthy : nor
does the sulcus lunatus appear to be present. Forel and Onuffo-
wicz have collected records of no less than twenty-seven instances
of brains lacking the corpus callosum more or less completely. In
some of these cases the brain was microcephalous, presenting
features which will be referred to in the sequel. In some instances
not only was the corpus callosum absent, but the fornix with the
psalterium, the septum lucidum, and even the anterior commissure,
might be undeveloped, as we have seen occurred in the cyclopian
brain just described.

Professor Elliott Smith has kindly put at my disposal photo-
graphs of two brains of native Egyptian Fellaheen women, in
which the coqius callosum is quite rudimentary. But in both
brains, the neopallium is normal in amount and appearance.
Exceptions thus occur to the general statement (made on p. 398)
viz. that the size of the corpus callosum bears a direct relation
to the mass of the neopallium. And since, as remarked, the
neopallium in these Egyptian brains is not less massive than
usual, the disposition of those fibres which would normally cross
in the corpus callosum, but which do not do so here, must remain
enigmatical.

C. The last group to be considered comprises examples of the
pathological condition known as Microcephalus. In these cases
of idiocy, the growth of the brain is arrested prematurely ; the
neopallium and its convolutions are involved in this condition ; and
as a result, the growth of the cranium is aborted. The cranial
form accompanying Microcephalus is thus quite peculiar, since
the facial parts may attain full development while, the cranium

448

ANOMALOUS CONDITIONS OF THE CEREBRUM [SECT. C

Olf. N

Fissure. o|

Sylvius (.post. Iirr)lyj

Sulcus

luijatuS

Cc^+ral Sulcus
CHol)

prj t.apd

Sulci of

"Rcll

corgbir^ed

Fig. 270. The right cerebral hemisphere of a microcephalic idiot girl (Bertha
Roemer). This brain shews a remarkable similarity to those of the Simiidae
(cf. Fig. 271). The specimen is in the Anatomical Museum at Halle and, though
referred to by Giacomini (Z Ccrvelli dci Microcefali ) as very remarkable, has never
been described in detail.

I rjtYc* parietal sulcus

Sulcus /[

lurjatus

Cent fa l Sulcus

OW)

"Sup.

Irjsula\ *4 trDv‘lOc
u • Sulcu?

occipital ; Fissure \ -u .7
6uicu£> ‘’Parallel of Sylvius n%°T K«-‘
sulcus (post. lirr)l>3 °lf O'

J\ f)t. lirr^itirjg
Sulcus

of l^eil

(tror)to-or()ital )

Fig. 271. The right cerebral hemisphere of an anthropoid ape (a Gorilla) for
comparison with the cerebral hemisphere of the microcephalic human being. (Mut,
Anat. Gant. W. L. H. D. del.)

CHAP. XV] ANOMALOUS CONDITIONS OF THE CEREBRUM

449

is disproportionately small. Without entering into further dis-
cussion of the relations of brain-growth and skull-growth, nor
even considering the possibility of discriminating between micro-
cephalous individuals, with a view to separating purely pathological
cases from such as may justifiably be relegated to the category

Fig. 272.
from above.

Central

I sulcus (Ro!)/

Irjtraparieta!

Sulcus>

Sulcas lut^aTus

The microcephalic human brain represented in Fig. 270, here viewed

<£erjt>al

Sulcus

l^trapanetal

Sulcus

lurjat us

enrrvniri aJ* .£.rT of . a Gori,lla (Mu»- Anat. Cant. “PI”), as seen from above • for
comparison with the microcephalic human brain shewn in Fig. 272.

D. M.

450 ANOMALOUS CONDITIONS OF THE CEREBRUM [SECT. C

of veritable atavistic productions, it must be repeated that the
result, so far as the encephalon is concerned, affects principally
the neopallium ; incidentally, the rhinencephalon may be thrown
into undue prominence, but the chief distinction between the
microcephalic and the normal cerebrum lies in the cortex, and
particularly, as has been said, in the neopallial folds. These
are found to have been arrested in growth, and may correspond
in their permanent arrangement to the stage normally reached
by the foetus at any time from the commencement of the fifth
month of existence ; nor should the parallel be drawn with these
brains only, but also (and with even more striking results) with
those of the Simiidae, while resemblances of detail may be traced
to lower and even non-primate forms such as the Ursidae
(Carnivora). The accompanying figures (270, 271, 272, 273)
bear out the foregoing remark as to the close similarity be-
tween the microcephalous cerebrum and those of the Simiidae,
and attention is specially directed to the incompleteness of
the frontal operculum of the insula, and to the well-developed
sulcus lunatus exhibited by the specimen shewn1.

IV. Palaeontology. The amount of available material for
the study of the encephalon from the standpoint of Palaeontology
is necessarily very scanty in amount. For owing to the perish-
able nature of the tissues, we are confined to inferences drawn
from the features of the skull in which the encephalon was
contained. From these, we can infer little or nothing regarding
parts of the encephalon other than the cerebrum, if we except
surmises of a general character as to the proportionate bulk of
the cerebrum and cerebellum.

Casts2 of the endocranial cavity are most conveniently employed
for these studies : and they will also provide information as to the
proportionate length and breadth of the cerebrum.

1 Of. Giacomini, I cervelli dei Microcephali ; also Cunningham and Telford,
The brain of the Microcephalic idiot. But the subject has now a very extensive
literature, which could not well be recorded in this place.

2 The best work on the brain-casts of the Primates in general, is that of Elliott
Smith. Cat. Mus. Roy. Coll. Surgeons.

451

CHAP. XV] PALAEONTOLOGY OF THE CEREBRUM

Beyond this, the evidence is indirect, and indeed, as regards
the Hominidae, the existing members of the Primates provide so
complete a series of examples demonstrating the evolution of the
specially human features of the cerebrum, that in one instance
only can the study of fossil forms be expected to throw light on
this part of the subject.

That instance is the fossil Primate-form known as Pithecan-
thropus erectus, the characters of which are more fully discussed
in Chapter XVII. In the present connection it will suffice to
mention, that the characters of the cerebral hemispheres of
Pithecanthropus erectus have been ascertained with fair accuracy
from the impressions on a cast of the interior of the skull-cap ;
and that moreover, both in respect of relative bulk and of the
conformation of the neopallial convolutions, the encephalon of
Pithecanthropus supplies confirmatory evidence as to the posi-
tion claimed for it, viz., intermediate between the families
Simiidae and Hominidae1.

The endocranial cast of the Neanderthal cranium bears the
remarkable button-like protrusion of the occipital end of the left
cerebral hemisphere which is described by Elliott Smith as con-
stantly associated with a well marked sulcus lunatus.

Elliott Smith has examined several specimens of desiccated
brains of very ancient inhabitants of Egypt. These brains still
shew traces of the gyri and sulci, which differ in no important
respects from those of modern Hominidae2. A similarly preserved,
but much less perfect brain was found in the cranium of an ancient
(Mound-builder period) inhabitant of Ohio3. No details of its
structure are on record.

1 Cf. Dubois. Internat. Congress of Zoology. Cambridge 1898. It is noteworthy
incidentally, that Dubois in the above communication lays much stress upon the
relatively large size of the third or inferior frontal convolution as shewn in
the brain-cast of Pithecanthropus erectus. This cannot however be claimed as a
human feature, for Cunningham has pointed out that the relatively large inferior
frontal convolution characterises the Simiidae rather than the Hominidae.

2 Elliott Smith, J. A. and P. Vol. xxxvi. p. 375.

3 Woodhull, Z. fur Etlin. Band 33.

29—2

CHAPTER XYI.

THE MORPHOLOGICAL VARIETIES OF THE HOMINIDAE.

Having thus completed the description of the methods of
investigation, it is now time to turn to the results of research
in the field of comparative human morphology; and in the first
instance it will be well to consider the morphological types of the
human skull ; while secondly, we shall find some evidence, to shew
that by taking cranial morphology as the first criterion, and
adding criteria derived from other parts of the skeletal system,
as well as from other anatomical systems, a classification of human
races may be based upon these morphological foundations.

In no department of Physical Anthropology is more literature
available than in the field of comparative craniology1.

That the diffei’ences in form are immense, is immediately
apparent on an even cursory inspection of any large collection of
human crania, and especially if these are of European provenance.
Without dwelling further upon the difficulties of classification, we
must approach the subject more nearly, and, from an examination
of the actual specimens, draw such conclusions as may be ap-
plicable to the problem before us.

In the first place, we have to eliminate the variations de-
pendent on age and sex, and consequently our first task will be
to re-consider the characteristics of immature crania. In a
preceding chapter much attention was paid to the characters of
the human foetal cranium at the termination of intra-uterine life :
it will therefore be unnecessary to re-open this side of the

1 Moreover this side of the subject has been popularised, and presented in a
distorted form to the public, in the guise of Phrenology, which has impressed on its
devotees a false idea of the fixity of cranial form in the several human races.

THE H0MIN1DAE

453

CHAP. XYl]

question. But a few words may be added in description of the
more salient features of the skulls of children, and in this
connection special reference must be made to Merkel’s researches
on growth changes in the skull from infancy to maturity.

Turning from the descriptive side of craniology to the results
of measurements and the consequent determination of indices,
we may notice that the infantile cranium tends on the whole
to brachycephaly, though actually during parturition, pressure
may temporarily produce elongation and even extreme dolicho-
cephaly (exceptions to this statement must be made in the case
of what is termed unreduced occipito-posterior or vertex presenta-
tions)1. The alveolar index is represented by figures denoting
less prognathism than in adults (in spite of Merkel’s statements),
and the nasal aperture is very wide in proportion to its height :
the face is narrow (leptoprosopic), and the zygomatic arches
invisible in the vertex view of the cranium (crypto-zygous). The
orbits are megaseme ; and the weight of the skull is small, in
proportion to the figure representing its capacity (cranio-cerebral
index).

In the next place, the senile type of cranium falls under
consideration here. As in the infant so in the aged skull, the facial
skeleton is reduced ; but essential differences obtain : in the infant
the maxillary antrum is undeveloped, the teeth have not yet
made their way to the surface, and in the mandible the alveolar
component is predominant. In the senile skull, and with the
loss of the teeth, the alveolar parts of the maxilla and mandible
tend to recede and disappear by absorption, and of the mandible
there may remain practically little more than the body. In infant
and octogenarian alike, the mandibular angle is more widely open
than in the intervening stages. The second remarkable feature
in senile crania is the closure of sutures by synostosis : this closure,
which is in progress throughout life, may in aged persons become
practically universal. Finally the skull as a whole tends to
become somewhat lighter, in consequence of absorption of the
tissues ; and though instances of senile thickening are not un-
common, they are not certainly free from the suspicion of owning
a pathological origin.

1 Cf. Budin, Traite des accouchements.

454 THE MORPHOLOGICAL VARIETIES [SECT. C

In the third place, the sexual differences obtaining in crania
are to be noted. From the descriptive point of view the female
skull presents the following characters. The skull as a whole
is slighter, less massive and of smoother surface than that of the
male: with respect to the cranial part, a striking feature is the
lack of prominences, whether such as the supra-orbital ridges
connected with air-spaces, or such as the temporal ridges, nuchal
lines, and mastoid processes, associated with muscular attachments.
The temporal ridges are farther removed from the sagittal suture
than in the male skull. The sagittal contour of the cranial vault
is frequently flattened near the bregma, the character when ex-
aggerated giving rise to the appearance described as clinocephalic.
The frontal bone rises more vertically and abruptly than in male
crania.

The characters of the supraorbital ridges have already been
mentioned. The orbital margins are finer and generally possess
a sharp edge. The zygomatic arches are more slender than in
male crania ; the maxillae and teeth, and indeed the whole facial
skeleton, are smaller than in male crania. The occipital condyles
are narrower. Manouvrier has pointed out that, in many of the
foregoing respects, the female skull shares with the infantile
skull, a position indicative of higher morphological development
and specialisation than that attained by the male.

When the craniometrical side is studied, we are surprised to
find a slightly greater degree of prognathism, which is explained
by the projection of the lower part of the face, especially the
alveolar margin of the maxillae; this subnasal projection more
than compensates for the otherwise small proportions of the facial
skeleton. The latter is to be designated leptoprosopic, from
observations on the facial index : and the stephano-zygomatic
index provides a higher figure than for male crania. In conse-
quence of the greater vertical orbital height and the associated
lack of prominence of the supraorbital ridges, the orbital index
provides a higher figure, i.e. is more megaseme, in the female skull.
Lastly, the cubical contents are less than in the male, the factor of
absolute bulk being naturally influential in this respect.

Such then are the more prominent characteristics of the
feminine cranial type: but it must be remarked that there are

OF THE HOMINIDAE

455

CHAP. XVl]

many instances in which it is not possible to assign with certainty
a skull to one or the other sex. This uncertainty is more generally
due to the male cranium tending to assume feminine characters
than the converse, and such ambiguity seems more frequent among
members of the most highly civilised communities. But the
negro races offer a very curious study in this respect: for though
among the Oceanic negroes there are found some of the most
striking contrasts due to the development in each sex of cranial
characteristics peculiar to it1, yet in the case of many African
negro tribes, the sexual cranial differences are as completely veiled
as in any examples that can be adduced.

The ground having thus been cleared by eliminating the
special cases of immature, senile, and female cranial characters,
we are now in a position to undertake the study of a large
collection of human crania gathered from all parts of the world.

To attempt to reduce the innumerable forms to some natural
order, we must select from the list of characters and indices a
certain number, remembering that unsatisfactory results are just
as likely to accrue if we demand too many qualifications, as when
too few tests are employed. Description from inspection, measure-
ment, and calculation of indices from the data thus provided, are
the first steps in the investigation. And as a result, variety and
diversity of conformation will be found to obtain in respect of any
character we may select. For the purpose of explaining the
results, let us select the breadth index as an example. Judged
by this test, we find crania varying in proportions from the very
narrow to the extremely broad. But when we add other tests, we
do not find that very narrow or very broad crania are always
associated with great prognathism, or small capacity, and thus we
are arrested in our endeavour to place one above the other, in
what we have called the natural order or series which we desire to
discover.

Leaving for the moment the respective claims of skulls
of each form, whether long, or short, to be considered the more
highly evolved, the following aspect of the subject is submitted
as likely to lead to practically useful results. Support is claimed

1 Excellent examples may be seen among crania from New Britain in the
Anatomy School, Cambridge.

456

THE MORPHOLOGICAL VARIETIES

[SECT. C

for the view that primitively neither dolichocephalic nor brachy-
cephalic tendencies were so intense as they have subsequently
become : it is submitted as highly probable, that primitively the
cranium was in a comparatively undifferentiated state, though
possessed of latent powers of specialisation, just as a primitive
morphological animal form may be undifferentiated as compared
with its specialised descendants.

Such a point of view may be termed monogenist, but it is to be
most clearly distinguished from the totally different monogenistic
views which were the arena of such controversial displays in
the history of anthropological study in the XIXth century.
Here we simply postulate the existence of a common stock of
humanity, not clearly differentiated into groups by their skulls.
The examination of large collections of human crania leads one to
favour such a view. It must be reserved for wide investigations
to prove or disprove its correctness, and we must not overlook the
fact that evidence may be brought against it1. But for the
moment, and apart from such considerations, the assumption of
the former existence of such an undifferentiated skull-form is
of very great use in illustrating the systematic relations of existing
cranial types. For the primitive stock may be compared to a
sheet of water, the margins of which accommodate themselves to
the shores, and just as the periphery of a lake or inland sea may
be marked by rounded bays or narrow fiords, so the original skull-
group has thrown out offshoots, some to a smaller, others to a
greater distance from the parent stock, the distance traversed
representing the degree of specialisation undergone. An even
better simile, perhaps, is that of an amoeba or some such amoeboid
protoplasmic mass as is seen in that lowly form of plant-life,
Aethelium septicum (a fungus of the Myxomyces group). In
these organisms pseudopodia are protruded, some bud-like and
apparently truncated, others elongate and slender, not only in two,
but in three dimensions of space. So we may imagine the
specialised long and short cranial types to represent offshoots from
the generalised stock, which is continually by trial and experiment
adapting itself to its changing environment.

1 Gf. Karl Pearson, Phil. Tram. Roy. Soc.

CHAP. XVI]

OF THE HOMINIDAE

457

For further illustration, we may select three cranial characters ;
variable, so that we may distinguish sub-groups or types by the
mode in which they are presented to us by a collection of crania.
And the reason for the limitation to three, will easily be understood
from the preceding reference to the dimensions of space. After
considering the effect of applying a threefold qualification, we may
proceed to discuss the results obtained when a greater number of
criteria are combined. The tests then that we shall select are
(1) the proportion of cranial breadth to length as illustrated by
the Breadth Index : (2) the degree of Prognathism : (3) the

cranial Capacity, as evidenced by the figure representing the
cubical contents, or by the cranio-cerebral index.

We may now treat of the first two of these characters, and
survey the results in Fig. 274,

which has been constructed
in the following way. Two
axial lines cross each other at
right angles. Considering first
the horizontal line, we premise
that examples above it tend
towards dolichocephalic cranial
proportions, while those below
are comparatively brachyce-
phalic. With regard to the
vertical axis, the right side
corresponds to prognathism,
increasing with the distance
from the axis ; and the left
side is set apart for ortho-
gnathic examples. The results
have been worked out approxi-
mately to scale on “quadrille”

Prosltyoryc ]r)d«*

Cephalic

Irjdex

q6 qj qc qq

02 'OS 10*

Fig. 274. Diagram to represent the

" t . i • . , • j relations of several human racial types

paper, but a qualitative demon- a8 indicated by their cranial features.

stration will suffice for the Figures in the vertical column represent
... . values of the cephalic index, those in

moment. 1 he diagram shews the horizontal line being values of the

us an irregular figure consisting Prosthionic (or alveolar) index,
of a central mass from which

project processes (pseudopodia): translating these into craniological

458

THE MORPHOLOGICAL VARIETIES

[SECT. C

terms, each corresponds to a specialised skull-type, which has
become to a certain extent (varying from type to type) separated
from the main mass of indefinite forms, whence such varieties arise
in response to the influence of certain agencies, whether natural,
sexual, or other selection. The distance by which any type-form
is thus separated, is indicated by the length of its pedicle, and
this gives an indication of the uniformity of that type, and of
its constancy in its own particular territory. Yet no type is
isolated: each has a pedicle or stem, for the most extreme cranial
form is linked to the generalised type by a chain of intermediate
examples so numerous as to make the transition an imperceptible
one1. The diagram thus indicates that certain types of skull may
be clearly differentiated from the mass, and moreover that special-
isation has been dii’ected along the lines (as denoted in the choice
of the criteria) of proportionate breadth or narrowness in the first
place, and of greater or less projection of the jaws in the second.
We thus see four groups of crania, indicated by the position of the
“pseudopodia” relatively to the two axes that have been drawn,
and we distinguish the classes according to these positions as

1. Dolichocephalic prognathous,

2. Brachycephalic prognathous,

3. Brachycephalic orthognathous,

and 4. Dolichocephalic orthognathous groups.

We now proceed to consider these in detail, taking them in
any order, but conveniently we may follow that of the clock-hand.
We notice two long processes marked I and II in the dolicho-
cephalic, prognathous class, differing both in dolichocephalic and
prognathic characters to some degree, the former being more
dolichocephalic, the latter more prognathous. The second quadrant
contains two processes likewise, but these are not considered suf-
ficiently divergent to necessitate numerical distinction and will
be bracketed as III (brachycephalic and prognathous crania).
In the next quadrant we find one irregular process, to which the
number IV is applied, and with it a closely associated process runs
across the boundary into the fourth quadrant. Skulls of group IV
are mainly brachycephalic and orthognathous, but the transition

1 With this figure may be compared the suggestive diagrams published by Petrie
and by Thomson. Cf. Man, 1902, Nos. 61, 95, 118.

CHAP. XVI]

OF THE HOMINIDAE

459

is very easy to the dolichocephalic orthognathous group, from
which two pesudopodia project near the dividing line, between
ortho- and prognathous crania, while a third is more nearly
approximate to the dolichocephalic prognathous group. The last-
mentioned groups are numbered V, VI, and VII respectively.
It remains to trace their relations when the third criterion, viz. of
cranial capacity, is added, To see these, we must draw a second
diagram (cf. Fig. 275), which represents our model of the hypo-
thetical skull-forms (as shewn in Fig. 274) viewed from the side,
in such a way that what is uppermost in Fig. 274, is to the right
hand in Fig. 275. The latter figure is in reality simpler in

« 61 60 f<5 f6 | ft J'6 ]5 f~7'i 72

Fig. 275. Diagram to represent the relations of several human racial types,
as indicated by their cranial features. The figures in the vertical column represent
values of the cranial capacity, those in the horizontal line being values of the
cephalic index.

construction than Fig. 274, for account is taken of one new character
only, and so we have in the first place a horizontal axis: values
of megacephalic skull capacity (cf. the classification by the cranial
capacity) place examples above, while microcephalic values place
examples below, the axis. The vertical axis is drawn in a vertical
plane through the axis xy of Fig. 274.

Fig. 275 shews us that we must distinguish among the

460

THE MORPHOLOGICAL VARIETIES

[SECT. C

groups I— VII provided by Fig. 274, those of lesser from those
of greater capacity. For we see that, again proceeding as before,

Groups IVb, V, VI are of great capacity (and dolichocephalic
and orthognathous, v. Fig. 274).

Groups I, II, are of small capacity (and dolichocephalic and
prognathous, v. Fig. 274).

Group III is of small capacity (and brachycephalic and
prognathous, v. Fig. 274).

Group IV A is of great capacity (and brachycephalic and
orthognathous, v. Fig. 274).

Group VII is of small capacity (and also dolichocephalic and
orthognathous, v. Fig. 274), and when this list is revised so as to
bring the groups into their numerical order, it is seen that:

Group I consists of skulls which are dolichocephalic, progna-
thous and of small capacity.

Group II consists of skulls which are dolichocephalic (less so
than Group 1), prognathous (more so than Group I), and of small
capacity (but not so small as Group I).

Group III consists of skulls which are brachycephalic, pro-
gnathous, and of small capacity.

Group IV consist of skulls which may be either dolicho- or
brachycephalic, which are orthognathous and of large capacity.

Group V consists of skulls which are dolichocephalic (more so
than the dolichocephalic members of Group IV), orthognathous
and of large capacity.

Group VI consists of skulls which are dolichocephalic (more
so than either Group V or the dolichocephalic contingent of
Group IV), orthognathous and of great capacity (exceeding both
Groups IV and V).

Group VII consists of skulls which are dolichocephalic,
orthognathous, and of small capacity.

We have thus become cognisant of seven groups of crania,
which may be considered as representing terminal forms, when
judged by their morphological conformation. It must not be
forgotten however, that laboured as the foregoing explanation is, it
is yet incomplete, because three characters only have been selected ;
this is admittedly a small number, but with an increase in the
number of criteria, much complexity in setting forth the results

OF THE HOMINIDAE

461

CHAP. XVI]

would have ensued. Further it is to be noticed, that only the
extremely long “ pseudopodial ” processes have been selected as
groups: the diagrams 274 and 275 would be more accurate if
innumerable bud-like processes were made to jut out round the
whole periphery of the central mass, so as to represent the less
clearly differentiated skull-forms of types, as well as those comprised
in the above list.

Again, the diagram shewn in Fig. 274, is “centred” on the
intersection of two lines, one of which is horizontal and corre-
sponds to the numerical value 77'5 for the breadth-index, the
other (vertical) line corresponding to an alveolar index of 100-5.
But in an earlier period in the history of the Hominidae the
centre might well have been determined by other lines, such for
instance as would reveal the mean human type as more dolicho-
cephalic and more prognathous than at present.

Actually however, the foregoing method and classification is at
least a working one, and we find that when we impose other tests
and criteria, the relative positions and prominence of the several
groups are not very sensibly altered. We shall therefore proceed
to add to each group some other characteristics which will serve for
its further differentiation from the rest ; and it will also be possible
to assign to each a certain number of specific characters, drawn
from other morphological systems, clear evidence that we are here
at least on the track of, if we have not actually attained, that
natural system, of which we have been in search. And since some
nomenclature is almost a matter of necessity in addition to
numeration, the geographical distribution (rather than so-called
racial nomenclature) may be used as further defining the several
groups, which we may now call types. The synonymy then works
out in the following manner.

Group I. Australian.

Group II. African (negro).
Group III. Andamanese.
Group IV. Eurasiatic.
Group V. Polynesian.
Group VI. Greenland.
Group VII. South African.

462

THE MORPHOLOGICAL VARIETIES

[SECT. C

From what has already been said, it follows that in these
geographical areas, the environment tends to the perpetuation
of the particular cranial form associated with the name in this
list. But that, although the predominant cranial form is of
this kind, other forms are not necessarily excluded from sporadic
occurrence, and in fact the type-form of one area may be
closely imitated by an occasional sporadically-occurring anomalous
form in a second area. Thus, for instance, is explained the
occasional appearance in European collections of anomalous cranial
forms undoubtedly of European provenance, which nevertheless
closely resemble the form of cranium normal among African
negroes.

Thus are explained the occurrence in Egypt, of Soudanese
skulls closely resembling those of aborigines of Australia, or
of crania resembling those of the South African group (unless
indeed in the latter case there has been an unsuspected north-
ward extension of the latter group in bygone ages1).

We must further note that two groups or types, viz. Nos. Ill
and VII, are associated with pygmy stature: other pygmy races
exist, but the cranial characters of these enable them to be brought
into line with one or other of the existing groups, including of
course Nos. Ill and VII themselves*.

Finally we may remark that of the seven specialised forms
distinguished in the foregoing list, the first presents the greatest
number of simian characteristics combined in one type, and the

1 It is because the Hominidae are so capable of overcoming the geographical
barriers which impose such definite limits upon the extension of many animals, that
the study of the geographical distribution of racial types is constantly diminishing
in importance and value.

2 Since drawing up the foregoing scheme of the relations of human racial types,

I have seen the diagram prepared by Stratz in illustration of a memoir upon this
subject published in the Archiv filr Anthropologic (1900). The author therein
groups the several human types around the aborigines of Australia taken as a central
unit, and as a prototype ; and the colour of the skin is used in the first instance as
a criterion. To me this scheme appears unsatisfactory, for there is no little evidence
to the effect that the aborigines of Australia are in certain respects highly specialised
representatives of the Hominidae. Such “ centralisation ” of the aborigines of
Australia is a view much favoured at present by certain writers, especially perhaps
Schoetensack, cf. Zeitsclirift filr Ethnologic , Band 33, and Klaatsch, cf. Anatomische
Jiefte , 1902, but it is not appropriate to enter upon its detailed discussion here;
cf. Chapter xvin.

CHAP. XVI]

OF THE HOMINIDAE

463

same remark applies to other morphological characters associated
with this form of skull. The second group comes next in this
order, after which the evidence upon which the groups can be co-
ordinated becomes vague and indefinite, so that their morphology
as at present known will not alone suffice to reduce all the known
varieties of Man to an order representing their respective grades of
evolution. This conclusion points to the necessity for extended
research, directed to every anatomical system in the several groups
submitted to the investigation.

The characters of the several Groups will now be enumerated
in order.

Group No. I.

Synonym. Australian.

Distribution. Australia with Tasmania, Melanesia, New
Guinea: sporadically throughout Oceania, and also in Africa.

Indices of skull. ( Average value in males.) Cf. Figs. 276, 284,
292. Breadth 7095. Alveolar 1011. Nasal 551. Height 7 TO.
(In the hypsi-steno-cephalic variety (common in Melanesia) this
index has a somewhat greater numerical value.)

Figs. 276—283 incl. Representative cranial types I — YII (corresponding to the
seven Groups described in the text) seen in norma verticalis : the figures are
reduced so that the maximum cranial length is uniform throughout the series.
(Mus. Anat. Cant. W.H.L.D. del.)

464

THE MORPHOLOGICAL VARIETIES

[SECT. C

Fig. 278. Type III. Andamanese. Fig. 279. Type IV. Eurasiatic, subdivision A.

Fig. 280. Type IV. Eurasiatic, sub-division B. Fig. 281. Type V. Polynesian.

CHAP. XVl]

OF THE HOMINIDAE

465

Fig. 283. Type VII. South African.

Figs. 284 — 291 incl. Representative cranial types I — VII. seen in norma lateralis ;
the figures are reduced so that the basi-nasal length is uniform throughout the
series. The extraordinary range of variety in this dimension is expressed by the
difference in size of the drawings when the latter are thus proportionately reduced.
(Mus. Anat. Cant. W.L.H.D. del.)

Fig. 284. Type I. Australian.

D. M.

466

THE MORPHOLOGICAL VARIETIES

[SECT. C

Fig. 285. Type II. Afrioan.

Fig. 287. Type IV. Eurasiatic, sub-divison A.

CHAP. XVI]

OF THE HOMINIDAE

467

Fig. 288. Type IV. Eurasiatic, sub-division B.

Fig. 290. Type VI. Eskimo.

30—2

468

THE MORPHOLOGICAL VARIETIES

[SECT. C

Fig. 291. Type VII. South African.

Figs. 292 — 299 inch Representative cranial types I — VII. seen in norma
facialis, (il/w-s. Anat. Cant. W.L.H.D. del.)

i i /

Fig. 292. Type I. Australian. Fig. 293. Type II. African.

CHAP. XVI]

OF THE HOMINIDAE

469

Fig. 296. Type IV. Eurasiatic, sub-division B. Fig. 297. Type V. Polynesian.

Fig. 298. Type VI. Eskimo.

Fig. 299. Type VII. South African.

Cranial Capacity. 1246*5 c.c.

Cranial description. The most striking features are the long
narrow skull, the very prognathous face, heavy brow-ridges, and
keeled cranial vault.

470 THE MORPHOLOGICAL VARIETIES [SECT. C

(a) Cranial portion. Long, narrow, phaenozygous, “ill-filled,”
scaphoid : muscular ridges distinct, temporal ridges closely approxi-
mated on parietal bone : the mastoid processes are small, but brow
ridges and occipital lines are massive and prominent. Sutures
simple: metopism very rare: fronto-squamous suture at the
pterion in about 17 °/0 of cases1. Grooves on the frontal bone are
rare2.

(b) Facial portion. Prognathous. Brow-ridges massive. Outer
orbital margins bevelled : lacrymo-ethmoidal suture short. The
nasal bones are flattened, slightly upturned inferiorly, wider above
than below, and meet at an obtuse angle. The nasal aperture is
wide, with indistinct lower margins : prenasal grooves are not
uncommon, but the normal appearance is that described as
orygmo-craspedote3. The palate is elliptical or hypsiloid: the
teeth, especially the molars, are large : the tuber maxillare is
large. The glenoid fossa is shallow, the styloid process very short,
and anomalies in the region of the foramen magnum are frequent.
The sigmoid notch of the mandible is shallow.

Associated characters. 1. Stature. The stature of males is
about 1668 mm. ($ 1568).

2. Skeleton. The cervical vertebral spines are not bifid, but
slightly tuberous as in the Simiidae.

The lumbar curve of the vertebral column is not so pronounced
as in white races, the lumbar index (107'8) being koilo-rachic and
simian.

The male sacrum is sub-platyhieric or of mean proportions.
The simian sacral notch is uncommon, though not unknown4.

The proportions of the pelvis as a whole are often simian.
But the ossa innominata are not specially simian in either sex.

The pelvic brim (in males) is dolichopellic and transversely
narrowed.

1 In Tasmanian aborigines this suture hardly ever occurred, but in Mallicollo
natives' the percentage of occurrence is over 50.

2 Cf. Dixon : J. A. and P. Vol. xxxvm. These grooves lodge branches of the
supra-orbital and supra-trochlear nerves.

3 Macalister, J. A. and P. Vol. xxxii.

4 Turner’s results have been modified by those of Paterson to the above
effect.

OF THE HOMINIDAE

471

CHAP. XVI]

The scapula is (paradoxically) narrower and less pithecoid than
in white races.

The sternum is characterised by the frequency with which the
pre-meso-sternal junction is at the level of the 3rd costal
cartilage.

The sacral curvature is less than in Groups IV and V, greater
than in Groups II and III.

Angle of humeral torsion (average) 134°5 : (white races, 161°).

As regards the modifications, in form and in extent, of the
articular surfaces of the femur, tibia, and astragalus in relation
to the squatting posture, the skeleton in this Group only realizes
expectation in a modified degree.

The proportions of the limb bones are simian as regards the
tibio-femoral index, but not in respect of the other three indices
(radio-humeral, humero-femoral and inter-membral).

3. Skin. Colour : chocolate-brown. (No. 8 of Topinard’s
series1.)

4. Hear. Often abundant over the body in males : beard
well developed : the hair is densely pigmented, black, and wavy
(i.e. neither lank nor frizzled) : the hair of the head is long. In
children the hair colour is less intensely black. The hair follicle is
straight. On transverse section, the contour of the hair is a broad
oval (index 62 — 74).

5. Eyes. Iris dark brown : the sclerotic is not usually
pigmented.

6. Muscular system. The cutaneous musculature is less
differentiated than in Group IV.

7. Brain. In size and conformation, the cerebrum is dis-
tinctly inferior to that of the white races. (Cf. p. 432.)

Group No. II.

Synonym. African.

Distribution. The African Continent, with Madagascar2.
Indices of Skull. Average Value in Males (cf. Figs. 277, 285,
293). Breadth 73’6. Alveolar 104 4. Nasal 56-8. Height 73’5.

1 For this series, quoted here and in subsequent pages, see page 353.

2 In consequence of the widespread distribution of the African negro over the
New World, this cranial form now occurs in the American continent.

472

THE MORPHOLOGICAL VARIETIES

[SECT. C

Cranial capacity. 1388 c.c. ; and much more variable than in
Group I.

Cranial description. The skull is elongated and very pro-
gnathous, without marked brow-ridges : the nasal bones flat and
uniform in width.

Cranial portion. Long, narrow, not constantly phaenozygous,
not “ ill-filled ” ; ridges less distinct than in Group I ; mastoid
processes large, and styloid processes long : brow-ridges not
typically prominent : metopism rare : fronto-squamous suture at
pterion in about 16°/0 °f cases (Ecker 20°/o> Anutschin 12-8°/0).
Grooves on the frontal bones are very common1.

Facial portion. Very prognathous : brow-ridges not prominent:
sexual cranial differences often obscure : nasal bones flattened, not
upturned, as wide above as below, meeting almost in the same
plane : the nasal aperture is wide, with indistinct (orygmo-

craspedote) inferior margins. The teeth, especially the molars,
are large : anomalies in the neighbourhood of the foramen
magnum are less common than in Group I.

Associated characters. 1. Stature. Male, 1620 to 1741 mm.,
and thus including some of the greatest human examples.

2. Skeleton. Lumbar curve: this is koilo-rachic, the anterior
convexity being less distinct than in white races, but more definite
than in Group I.

The male sacrum is similar to, or broader than, that in
Group I ; the sacral notch, a simian feature (Paterson), is normal
and characteristic.

The sacral curvature is less than in any other Group.

The pelvic brim is wider than in Group I.

The proportions of the pelvis as a whole are sometimes simian:
but this is not the case with the ossa innominata in either sex.

The scapula is more pithecoid and broader than in the white
or yellow races.

Angle of humeral torsion (average) 144°: (white races 161°).

The modifications, in form and extent, of the articular surfaces
in femur, tibia and astragalus in relation to the squatting posture,
are only found in a modified degree.

1 Cf. Dixon, J. A. and P. Vol. xxxvm. The grooves are commonest in natives
of West and South Africa, and in Egyptians.

OF THE HOMINIDAE

473

CHAP. XVI]

The os calcis is stated to be unusually prolonged backwards.

The proportions of the limb bones are simian as regards the
tibio-femoral index, but not so as regards the intermembral, radio-
humeral, or humero-femoral indices.

3. Skin. The colour is typically intensely black, but variations
towards dark chocolate-brown, or even bronze and reddish shades
occur, as in examples 7 — 10 inclusive, of Topinards series of
colour types.

4. Hair. The colour is jet black: the beard is scanty: the hair
on the head is short and arranged in spirally coiled ringlets : the
hair follicles pursue a curved course, associated with the frizzly
character of the hair which on section has an elliptical contour
(index 40 — 60).

5. Eyes. The iris is of a dark brown tint, and the sclerotic
is in certain cases pigmented.

6. Muscular system. The system of cutaneous facial muscles
is less differentiated than in Group IV.

7. Brain. The brain is absolutely larger than in Group I,
but smaller than among the white races. (Cf. p. 436.)

Group No. III.

Synonym. Andamanese.

Distribution. The islands of that name, the Malay Peninsula,
the Philippines, while similar forms occur sporadically in other
geographical areas1.

Indices of Skull (cf. Figs. 278, 286, 294). Breadth 82T.
Alveolar 1020. Nasal 50'9. Height 7 7 *9.

Cranial capacity. 1266 c.c.

Cranial description. The skull is small and round, with pro-
minent jaws.

Cranial portion. The skull is cryptozygous : muscular ridges
are not very prominent : the mastoid processes are small, and the
external auditory meatus shallow. Brow-ridges are not developed,
and sexual differences are often obscure in these skulls. The frontal

1 Small broad prognathous crania occur in ancient cemeteries in Peru. This
must not be taken as a suggestion that the Andamanese natives ever formed part
of the population of South America, for the only feature common to the two areas
is the skull form, as judged by size, index of breadth, and the index of prognathism.
Moreover, nearly all the Peruvian crania are artificially deformed.

474

THE MORPHOLOGICAL VARIETIES

[SECT. C

bone very rarely joins the squamous portion of the temporal bone
at the pterion.

lacial portion. The face is prognathous, the prognathism
affecting chiefly the alveolar maxillary margin and being therefore
sub-nasal: the brow-ridges are feebly developed in both sexes: the
nasal bones are small, short, flat, and not wider below than above :
they meet nearly in the same plane. The inferior nasal margins
are indistinct.

Associated characters. 1. Stature. The association of a highly
brachycephalic skull with dwarf stature is sufficient to distinguish
this Group from Nos. I and II. The average statui'e for males is
1485 mm.

2. Skeleton. The 1 umbo- vertebral index denotes simian affi-
nities (koilorachic class).

The sacrum is sub-platyhieric (according to Paterson) and
characterised by the (simian) sacral notch. The sacral curve is
very slight: it is somewhat greater than in Group II, with which
this Group is hereby associated in the lowest position among the
Hominidae.

The proportions of the pelvis as a whole seem to be rarely
simian : with regard to the ossa innominata, the special human
characters are here strongly marked in both sexes.

The scapula is the most pithecoid known among the Hominidae,
with the possible exception of certain African dwarfs (Bambute).

The proportions of the limb bones are simian as regards the
radio-humeral and the tibio-femoral, but not as regards the inter-
membral or humero-femoral indices.

3. Skin colour. Black, corresponding to Group 10 of
Topinard’s series of colour types.

4. Hair. The hair is scanty, and the beard sparse. In form,
the hair is of the woolly or curly variety : in section the index of
the hair would be probably about 50 — 60.

5. Eyes. The colour of the eyes is dark brown.

6. Muscular system. No data are on record.

7. Brain. No data are on record.

Group No. IV.

Synonym. Eurasian.

Distribution. The continents of Europe, Asia, and a large part

OF THE HOMINIDAE

475

CHAP. XVl]

of America. As this form corresponds most closely to what may
be called the generalised form of human skull, its wide distribution
is thus intelligible.

Indices of the Skull. (Cf. Figs. 279, 280, 287, 288, 295, 296.)
Breadth : all varieties occur, from the dolichocephalic to the
brachycephalic form.

Alveolar : the index is also variable, but is usually less than 98 :
the skull is accordingly orthognathous.

Nasal : variable, but usually less than 48, and therefore
leptorrhine.

Height : variable, but usually less than the breadth index, the
height of the cranium being less than its breadth.

Cranial capacity. About 1500 c.c., and consequently megace-
phalic.

Cranial description. The general description of the human
cranium, as given in works on osteology is applicable to this
group. Thus the typically human combination of a large cranium
with a reduced facial skeleton is marked : the cranial surface is
uniformly rounded : the temporal ridges are feebly marked, and
lie far apart on the parietal bones. Sexual differences are often
obscure. The sutural lines are very tortuous. A parieto-sphenoid
junction in the temporal fossa is normal, the fronto-squamous
suture occurring in about 1 °/o of cases. Grooves on the frontal
bones are of rare occurrence1.

The nasal aperture has sharp margins : the nasal bones are
large, long, narrower above than below, and sharply inclined to one
another. The palate is small, and in contour parabolic. The
anterior lacerate foramen is widely open in the cranial base, the
glenoid fossa is deep, and the styloid processes long.

Within so large a group, subdivisions must naturally exist,
and the varieties of skull-form have been reduced by Kollmann to
five sub-groups, based on the respective values of the cephalic and
facial indices.

These groups are :

(1) dolichocephalic leptoprosopic,

(2) dolichocephalic chamaeprosopic,

(3) brachycephalic leptoprosopic,

1 Cf. Dixon, J. A. and P. Vol. xxxvm.

476 THE MORPHOLOGICAL VARIETIES [SECT. C

(4) brachycephalic chamaeprosopic,

(5) mesaticephalic chamaeprosopic,

the mesaticephalic leptoprosopic sub-group being so small as to be
negligible (at any rate in Europe).

Associated characters. 1. Stature: very variable, extending
from 1540 mm. to 1790 mm. in males.

2. Skeleton. The lumbar portion of the vertebral column is
strongly convex forwards, and therefore not simian.

The lumbo-vertebral index denotes the furthest separation from
the simian form.

The index of ensellure is small (numerically only half that of
Group VII).

The male sacrum is broad (platyhieric). The sacral notch is
rare, and the curvature is great.

The proportions of the pelvis as a whole are rarely simian.
In both sexes the ossa innominata have proportions more simian
than those met with in any other Group.

The transverse diameter of the pelvic brim is relatively great,
with proportionate diminution of the sagittal diameter; the brim
is thus platypellic.

The scapula is narrow in proportion to its length : it does
not however occupy the position furthest removed from the
pithecoid type.

The angle of humeral torsion averages 161 (Broca).

The proportions of the limbs as regards the inter-membral,
radio-humeral, tibio-femoral and humero-femoral indices are either
indifferent or not definitely simian : they are in certain instances
nearer the simian type than those of the three preceding groups
(notably in respect of the inter-membral index).

3. Skin. The skin is very variable in colour, the range
extending from the fairest blonde of Scandinavia to the ebony
blackness of the Abyssinian (the whole range of Topinards series
of colour types).

4. Hair. The hair-colour is also very variable : the extremes
are represented by Scandinavian blondes and by the negioM
Abyssinians, or by the natives of Hindostan. The degree of
hirsuteness is also variable, as seen in the contrast of the Ainus
with the Javanese.

OF THE HOMINIDAE

477

CHAP. XYl]

The hair follicle is straight in direction, and the transverse
sections of hair approach in contour to a circle rather than to an
ovoid or elliptical figure, with an index of about 65 — 70.

5. Eyes. The pigmentation of the iris varies in tint from the
lightest grey to the darkest brown, commonly called black.

6. Brain. The description of the brain as given in anatomical
text-books applies to this Group. Associated with a cranium of
great capacity, the brain is very large, weighing about 1330 gm.
on the average : its convolutions are extremely tortuous, and
operculation of the central lobe is complete. The sulcus lunatus
and occipital operculum are not however unknown, though statis-
tical data as to the frequency of their occurrence are still lacking.

Group No. V.

Synonym. Polynesian.

Distribution. Islands of Polynesia, viz. from Rotumah to Easter
Island, and from the Sandwich Islands to the Chatham Islands.

Indices of the Skull. (Cf. Figs. 281, 289, 297.) Breadth 804
(Hawaii). Alveolar 98'6. Nasal 47'9. Height 75‘5.

Cranial capacity. 1469 c.c.

Cranial description. The skull is large, and distinctly rhomboid
in shape, when seen from above, the appearance being due to the
development of the parietal eminences.

Cranial portion. The frontal bone recedes rapidly from the
glabella backwards, and the parietal region appears voluminous.
The brow-ridges are not prominent. Grooves on the frontal bone
are rare1.

Facial portion. There are large pre-nasal fossae below the
apertura pyriformis nasi, the fossae being bounded anteriorly by
the nasal margin of the maxilla, while posteriorly a second
maxillary ridge descends to the floor of the nasal fossa. The
nasal aperture is narrow, sometimes extremely so ; the nasal
bones though long, are narrow : they meet at an acute angle.

The angle of the mandible is much rounded, so that measure-
ment of the value of the angle is rendered difficult.

Associated character's. 1. Stature. The average stature varies

1 Cf. Dixon, J. A. and P. Vol. xxxvm.

478 THE MORPHOLOGICAL VARIETIES [SECT. C

from 1680 mm. to 1743 mm. (Deniker), including therefore some
of the tallest examples among the Hominidae.

2. Skeleton. The lumbar portion of the vertebral column.
The lumbo- vertebral index denotes simian affinities (cf. Turner’s
figures for Oahuans ; the number was however only three), but
data are scanty.

The sacrum is broad, and enters into the platyhieric group.
The simian notch is rare. As regards sacral curvature, no sure
data are available.

The proportions of the pelvis as a whole are far removed from
those of the Simiidae, and a similar remark applies to the ossa
innominata in both sexes.

The scapula presents typical human proportions, and occupies
an intermediate position, in the scale of races arranged according
to their scapular proportions.

Angle of humeral torsion (average) 144°: (white races 161°).

As regards the proportions of the limb bones, this group
occupies an indefinite, or indifferent, position.

3. Skin colour. Cafb-au-lait, or warm brown, corresponding
to No. 5 in Topinard’s series of colour types.

4. Hair. Black : wavy, or straight, with a sectional index
of about 62. The beard is scanty or absent.

5. Eyes. The iris is of a dark brown colour.

6. Brain. The brain of a Marquesas islander was charac-
terised by a simpler plan of convolutions than the brains of
white men1. In one Polynesian brain the sulcus lunatus has
been observed2.

Group No. VI.

Synonym. Greenland.

Distribution. Greenland, Labrador, and thence sporadically
along the northern coast of America to the eastern portion ol
the north coast of North Asia.

Indices of the Skull. Averages for males. (Cf. Figs. 282, 290,
298.) Breadth 7T5. Alveolar 100’6. Nasal 45‘3. Height 73*7.

Cranial capacity. 1546 c.c. (megacephalic).

Cranial description. The skull is large, elongated, and veiy

~ W.L.H.D. (specimen at Paris).

1 Cf. p. 440 supra.

CHAP. XVI]

OF THE HOMINIDAE

479

scaphoid, with immense malar bones, very narrow nasal aperture,
and flattened face.

Cranial portion. Dolichocephalic, cryptozygous, scaphoid without
sagittal synostosis: muscular ridges not prominent: mastoid processes
large : brow-ridges not large ; styloid processes stout and long ;
posterior margin of foramen magnum often notched. Sutures
simple. Grooves are rare on the frontal bones1.

Facial portion : no prognathism : the index shews that meso-
gnathism is the rule.

The orbits are high, and the infraorbital sutures often persist
(in adults) on the facial surface.

The nasal aperture is narrower than in any other Group. The
nasal bones are long, narrow, and inclined at an acute angle to one
another : the canine fossae are very shallow and often non-existent,
as the maxilla is prominent in this region. The mandible is broad,
and the gonio-zygomatic index, 82'5, provides the highest known
figure in the Hominidae'2. The mandible often presents a curious
thickening which affects chiefly the body.

Associated characters. 1. Stature. The average stature
of males is 1621 mm. (Deniker)3.

2. Skeleton. The lumbo-vertebral index assigns to this Group
a place lower than Group IV (the highest), but the difference is
not great. The Group is orthorachic.

The sacrum is broad (platyhieric) and the simian notch does
not seem to be on record for this Group. No sure data are avail-
able as regards the sacral curvature.

Pelvic index. The proportions of the pelvis as a whole, and of
the ossa innominata, are not simian in either sex.

The proportions of the scapula are intensely human.

The proportions of the limb bones are simian in respect of the
intermembral and humero-femoral, but not in respect of the radio-
humeral or tibio-femoral indices: the determining factor is the
great relative length of the humerus.

3. Hair. The hair is black and lank ; it is not abundant, nor

1 Cf. Dixon, J. A. and P. Vol. xxxvm.

2 Soren-Hansen, Meddelelner om Gronland, Part x.

3 Soren-Hansen (op. cit.) gives an average of 1606 mm. for 140 men, 1506 mm.
for 110 women.

480

THE MORPHOLOGICAL VARIETIES

[SECT. C

is the beard constantly developed: in section the hair is nearly
circular, with an average index of about 80. (Latteux : quoted by
Topinard, El. d’A. p. 279.)

4. Skin. The skin colour is variable, within the range of the
lighter shades of yellow, i.e. Nos. 4 and 5 of Topinard’s series of
colour types.

5. Brain. No Group provides a heavier (average) cerebrum
than this.

6. Other features. The epicanthic fold at the inner angle
of the eyelids is common, though not universal.

Group No. VII. (Cf. Figs. 300 and 301.)

Synonym. South African: the aboriginal natives of this group
are rapidly disappearing. They are quite distinct from the true
Negroes or Kaffirs.

Distribution. A limited extent of South Africa, and sporadi-
cally in other parts of Africa.

Indices of the Skull ( average male). (Cf. Figs. 283, 291, 299.)
Breadth: from 74 to 75, just on the limit of dolichocephaly : the
females are distinctly mesaticephalic. Alveolar : mesognathous
(1015, Shrubsall), inclining to orthognathism ; this is a distinctive
feature of the group. Nasal : G0'2 (extremely platyrrhine).
Height: lower than the breadth index (70'8).

Cranial capacity. 1331 c.c. (microcephalic).

Cranud description. The skull is small, with flattened face,
small jaws, and remarkably vertical forehead; the brow ridges are
insignificant. The aspect is thus infantile.

Cranial portion. The skull is cryptozygous ; well-filled, i.e.
uniformly rounded, not scaphoid ; the brow-ridges and mastoid
processes small or insignificant : the temporal ridges widely

separated on the parietal bones. The sutures are simple, wormian
bones uncommon, and the fronto-squamous suture at the pterion
is rare. The sagittal median line of the contour is marked by
a flattening or depression, post- bregmatic in position, and the
occipital contour is rounded and bulging. Grooves are common
on the surface of the frontal bones1.

Facial portion. The face is small in proportion to the cranial
part, even for a human skull. The facial profile is remarkably
1 Cf. Dixon, J. A. and P. Vol. xxxvm.

CHAP. XVl]

OF THE HOMINIDAE

481

flattened, and if prognathism occurs, it is sub-nasal, affecting the
alveolar margin of the maxilla : the nasal bones are very flat, and
the characters of the nasal aperture exactly reproduce those of

—

Fig. 300. Pig. 301.

Fig. 300. Bush-man of South Africa1.

Fig- 301 Bush-woman of South Africa. The characteristic features of
inthi” individul ’ ^ ^ accumulation of Bluteal fat (steatopygia) are evident

1 Figs. 300, 301, and 216 (v. supra) have been kindly lent by Messrs H. Scott & Co.

D. M.

482

THE MORPHOLOGICAL VARIETIES

[SECT. C

African negroes of normal size (Group II). The palate is shallow
and elliptical, the mandible feebly developed, the chin not prominent
and the sigmoid notch shallow.

Associated characters. 1. Stature. The average stature is
1529 mm. in males (Deniker).

2. Skeleton. The lumbo-vertebral index (koilo-rachic class)
denotes simian affinities. The index of ensellure is on the average
(4 examples) 7-2 (numerically twice that of Group IV).

The sacrum is very simian : it is elongated (dolichohieric) : the
simian notch occurs in about 33-3°/0 of examples. The sacral
curvature is relatively very slight.

The curvature of the iliac crests is distinctly less than in
Group IV, and indeed most other Groups ; the pelvis is simian
in this respect.

Pelvic index. The proportions of the pelvis as a whole are
more nearly simian than in any other Group. The os innominatum
is simian or infantile. In his description of a bush pelvis Cleland1
notes the number of infantile features provided by it, as for instance,
the lack of development of the posterior parts of the ilia: the growth
of these is considered by Thomson2 as the most important factor
in producing the increase in transverse diameter which occurs in
white races (previously the increase had been largely ascribed
to transverse sacral growth).

As regards scapular proportions, the South African Group
occupies an intermediate position in the human series.

The proportions of the limb bones, as judged by the inter-
membral, radio- humeral, and humero-femoral indices, are not
simian.

3. Skin. Clear yellow in colour, corresponding to No. 4 of
Topinard’s series of colour types.

4. Hair. The hair is hot abundant : the males have little or
no beard : the hair of the head is distributed in the “ peppercorn ”
manner : the hairs are tightly coiled, and in section present a very
flattened elliptical contour (index about 46). The hair follicle is
curved.

5. Muscular system. The facial cutaneous muscles are less
differentiated than in white men.

1 British Association Report.

2 J. A. and P. xxxm.

CHAP. XVI]

OF THE HOMINIDAE

483

6. Other characters. Both sexes, but particularly the females,
are characterised by steatopygia, or the gluteal accumulation of
fat (cf. Chapter xiv. p. 361 and Fig. 301). In the females, the
labia minora are hypertrophied and elongated to an extraordinary
and characteristic degree.

MORPHOLOGICAL CHARACTERS OF THE PYGMY RACES.

In drawing up the scheme to demonstrate the chief morphological types
of the Hominidae, the presence among the seven representatives selected, of
two races of pygmy stature and proportions, was remarked1.

The inclusion of these pygmy types was unavoidable, inasmuch as the
tests first imposed related not to stature (which would at once have ruled
all pygmy races out of further direct comparison with the taller races),
but to the proportions of the skull. It is suitable to add brief notes
on the very remarkable pygmy types now known to exist in certain parts
of the world, and a few words will finally be added in description of the
remains of pygmy individuals supposed to be the relics of a pygmy stock
once inhabiting Europe. The descriptions will be arranged, not according
to the morphological characters, but according to the particular race, so that
the following pygmy groups will be considered, in addition to those (the
Andamanese and the Bush natives of S. Africa) already described.

I. (A) The Central African group, (B) the Semang of the Malay Peninsula,
and (C) the Aeta of the Philippine Islands. II. The Veddah of Ceylon.
III. Prehistoric European pygmies.

1 It is to be noticed that all dwarfs do not possess similar proportions. Dr
Birkner (in a pamphlet entitled “Einiges fiber Zweigenwuchs ”) has made a very useful
contribution to the subject of dwarfishness, if the adaptation may be permitted,
or Nanism. His observations were made on dwarfs from Burmah and from Ceylon.
He makes out a good case in support of his proposition to the effect that there must
be distinguished varying degrees of dwarfishness, or what may be styled total nanism
and partial nanism; the essential difference between the total and partial forms
consisting in the fact that true (total) dwarfs possess, in respect of limbs and trunk, the
proportions obtaining in adults of normal size ; whereas, in the partial or pseudo-dwarfs
(partial nanism), the trunk is relatively longer and the legs proportionately shorter
than in normal adults ; herein dwarfs of the latter class retain the infantile pro-
portions.

Dr Birkner believes that the so-called dwarf races will, when such a discrimi-
nating investigation is brought to bear on their physical proportions, present us with
examples of each class ; and he surmises that the Asiatic pygmies may very probably
fall into the category of partial dwarfs. To this a provisional assent may be
accorded, though it is believed that the dwarfs of infantile proportions are more
primitive than the “ true” dwarfs as defined by Birkner.

31—2

484

THE MORPHOLOGICAL VARIETIES [SECT. C

The geographical distribution of the pygmy races is indicated in the
accompanying sketch-map (Fig. 302).

Fig. 302. Map to represent the distribution (x) of pygmy races of Man.

Dwarf Group. I (A.)

Name. Central African. (Of. Fig. 303.) Three groups, viz., Bananda,
Bambute, Baamba, have been carefully investigated1. Many other tribes, such
as the Akka, Batvva, etc., await research.

Stature. 1452 mm. (in the Bambute).

Distribution. Uganda and adjacent regions.

Cranial indices:

Breadth. 79-2 (Bambute $ ). The Akka dwarfs are in certain in-
stances dolichocephalic (74'4 in a
male skull).

Alveolar. 107-4 (Bambute 5 )• This figure is exceeded by that (108‘7)

of an Akka dwarf

Nasal. 58'7 (Bambute $ ). This figure is exceeded by that (63 '4)

of an Akka dwarf ( £ ).

Height. 70-2 (Bambute £ ).

Cranial capacity. 1400 (Bambute 9 )• The Akka skulls are less capa-
cious (1070 — 1100 c.c.).

Cranial description. (Cf. Skrubsall’s account of the Bambute skull now in
the British Museum. The account will be found in Johnston’s Uganda
Protectorate , Yol. ir.)

(a) Cranial portion. Small, but not infantile : oval in norma verticalis :
the sutures not tortuous, the individual being advanced in years ; ill-filled :

1 See Shrubsall’s reports in Johnston’s The Uganda Protectorate, Vol. ii.

CHAP. XVl]

OF THE HOMINIDAE

485

Fig. 303. Two Bambute pygmies from Central Africa (from a photograph kindly
lent by Sir H. H. Johnston).

486

THE MORPHOLOGICAL VARIETIES

[SECT. C

ridges and mastoid processes are inconspicuous. The sphenoid joins the
parietal bone at the pterion. In the two Akka skulls in the British Museum,
the frontal and squamous bones join. A brief note on these skulls follows
the present account.

(6) Facial portion. The jaws are prognathous to a high degree (this
character is probably even more pronounced in the- Bananda). The orbit is
almost microseme, with small vertical diameter : the nasal aperture is wide,
the nasal spine small : simian grooves are present : the nasal bones are flat
and meet at a wide angle, thus lying nearly in the same plane. The palate is
elongated and narrow : the teeth large.

The mandible is slight, not massive ; the condylar and coronoid processes
arc short (i.e. infantile) : the sigmoid notch also infantile, being shallow :
the chin is pointed. There are general resemblances to Bush and to Akka
crania.

Three skulls of pygmies from Central Africa are in the Museum at South
Kensington. One of these is the Bambute skull already mentioned, the
other two are skulls of Akkas and have been described by Flower ( Journal
of the Anthropological Institute , Vol. ix. 1880). The following notes have
been made by myself, in reference to certain features not specially dwelt
on by other observers.

I. Akka skull (? 9 ) 5 with skeleton.

The spheno-maxillary fissure is widely open. On both sides the frontal
and squamous- temporal bones join in the region of the pterion. The lacrymo-
ethmoidal suture is not unusually short. The nasal margins are distinct.
No special features were noted in the teeth.

II. Akka skull ( f ); the frontal and squamous bones join on the right side,
but on the left the sphenoid and parietal bones just touch at the pterion.
The lacrymo-ethmoidal suture is distinctly short, and the nasal aperture
small. No specially simian features occur in the teeth ; the third upper
molar teeth are reduced in size as compared with the other molar teeth:
the third lower molar has a remarkably circular crown which is crenated.
The palate is elliptical in contour. No other features of importance are seen
at the base of the skull. This specimen is less prognathous than the
following.

III. Bambute ( 9 )• This specimen is very prognathous, and the spheno-
maxillaiy suture is widely open ; no special features characterise the teeth :
the sphenoid and parietal bones touch at each pterion. The lacrymo-
ethmoidal suture is not unduly short.

The nasal margins are obliterated interiorly ; at the cranial base small
paroccipital processes are seen on each side.

Lumbar curve. The vertebral column is koilo-rachic (index 102) but less
so than that of the Akkas (index 102'6).

Pelvis. The bones are slight : the iliac crests are less tortuous than in
tall races: the brim-index is dolichopellio (95-8) as in Bush and Andamanese
dwarfs: the breadth-height index is a simian feature, its value is variable,

CHAP. XVI]

OF THE HOMINIDAE

487

between 89'5 and 11T7 In Europeans the value is 74 (a Bush native had
an index of 91).

Scapula. The index (87-9) is extraordinarily low and simian, or even
“ therian.”

Femur. The neck joins the shaft at an angle of 138°.

The upper limb bones. The fore-arm is long in comparison with the arm :
the radio-humeral (ante-brachial) index being 79‘7. This is a slightly simian
feature. Living Bambute provide an average index of 9T6 (range 80 — 100T),
but allowance must be made for errors, due to the presence of soft tissues in
the living.

The lower limb bones. The tibio-femoral index (84T) is dolichocnemic
in the living subject (Bananda, Bambute, Baamba).

The humero-femoral index. Denotes a very long humerus (index = 80-3)
as determined in the living subject.

The inter-membral index. The index in the living is on the average 83 63,
this figure indicating much longer upper limbs than in the tall races.
(Cf. Chapter xiii. p. 331.)

Skin colour. The Uganda dwarfs present two varieties, viz. (a) reddish-
yellow, ( b ) jet-black.

Hair colour and character. The dwarfs with reddish-yellow skins, men,
women, and children alike, are characterised by the possession of a fine downy
lanugo-like covering of hair of reddish tinge,, longer on the legs and back,
and not tightly curled except that the axillary and pubic hair, like that
of the head, is tightly curled. The jet-black dwarfs have also hair on the
body, but more curly than in the foregoing group. Males of both types
have a slight moustache and sometimes a distinct beard. Women of type
(a) have often a trace of whiskers. All are less hairy than the dwarfs of
the Congo region. The hair of the head is lightly curled in all as in negroes.
In variety (a) the hair is never absolutely black in colour ; it varies from
an indefinite grey-green-brownish tint to a reddish tinge, the latter colour
being more pronounced on the more anterior parts of the head.

Miscellanea. The alae nasi are very large and rise as high as the central
part of the nose : this feature distinguishes the pygmy physiognomy from
that of the tall African negroes. In the prognathous pygmy type (Banande)
the long upper lip is a distinctly simian feature; the mouth is large, but
the lips are not so everted as in some negroes : the chin is receding.

Steatopygia is never so marked as in the Bush race ; in the Uganda group
(a), the buttocks may be even attenuated; this is a simian feature: the
upper limbs are longer and the lower limbs shorter relatively than in the tall
negroes of Africa, and are therefore infantile. The feet are well formed and
the toes long ; the hallux diverges from the smaller toes. Non-simian
characters are the narrowness of the jaws and the small numerical value of
the index of the external ear, in which these pygmies approach the white
races.

Of the anatomy of the soft tissues nothing is as yet known.

488

THE MORPHOLOGICAL VARIETIES

[SECT. C

Dwarf Group. I (B).

Name. Semaug1. (Cf. Fig. 304.)

Stature. 1525 mm. (av. of 23 ^ ) ; 1445 mm. (av. of 3 $ ).

Distribution. Limited ai’eas in the Malay Peninsula. Comparatively few
pure-blooded individuals exist. Remnants of another dwarf stock, the Sakei,
inhabit the same region, but whereas the Semang agree with the Andamanese,
the Aeta, and the Central Africau pygmies in the important characters of

Fig. 304. A young Semang negrito from the Malay Peninsula. (From a photo-
graph kindly lent by Dr N. Annandale.)

1 Cf. Skeat, Wild Tribes of the Malay Peninsula-, also Annandale and Robinson,
Fasciculi Malayenses.

CHAP. XYl]

OF THE HOMINIDAE

489

hair form, the Sakei resemble the Yeddah group, in which the hair is not
crisp and curly, but wavy. The Sakei will not be further considered here.

Cranial indices:

Breadth. 76'2 (av. of 4) ; in the living the index is 77'7 (av. of 20 $ ).

Alveolar. 99-7 (av. of 4, viz., Annandale 2; Skeat 1, Grubauer 1).

Nasal. 57-4 (av. of 3, viz., Annandale 2 ; Skeat 1 : Grubauer’s

specimen is purposely excluded).

Height. 77'3 (av. of 2; viz., Skeat 1, Grubauer 1).

Cranial capacity. 1230 c.c. (av. of 5, viz., Annandale 2, Turner 1,
Skeat 1, Grubauer 1, Virchow 1).

Cranial description. For this purpose the Semang skull now in the
Museum of the Royal College of Surgeons in London is appropriate (cf. Man,
1903, No. 18). Evidence of a low grade of evolution is not presented, and
the specimen is distinctly less simian than the Bambute skull, being less
prognathous and having a narrow nasal aperture.

The cranial portion. This is not “ill-filled”; but the brow -ridges are
prominent : in form the skull may be described as ovoid though short :
muscular ridges are not prominent.

The facial portion. Prognathism is of the subnasal variety: the orbits
are microseme, the nasal aperture is leptorrhine as judged by the index, but
allowance must be made for an unusually prominent nasal spine : the palate
is long and hypsiloid. The chin is prominent (such prominence is absent in
the living subject), the shortness of the ascending ramus of the mandible and
shallowness of the sigmoid notch constitute infantile features.

Lumbar curve. The index (97'5) shews that the vertebral column is
kurto-rachic, approximating to the type of the white races of tall stature.

Pelvis. The iliac crests are less tortuous than in the tall races of Man:
herein the Semang agrees with the Bush and other dwarf types.

Scapula. The average index (84-4) for the scapulae of a Pangan Semang
shews a distinctly simian feature.

The upper limb bones. The fore-arm is of moderate length as compared
with the upper arm : the result of observations on living Semangs shews that
the fore-arm is excessively long, but allowance must be made for the error
involved in measuring, which probably accounts for the discrepancy of results
derived from the skeleton and from the living subject respectively. A precisely
similar lack of correspondence in this respect is revealed by the data provided
by those who have examined the African pygmies and the Veddahs respec-
tively.

The lower limb bones. Messrs Annandale and Robinson ( Fascic . Malay-
enses, 1903) note that the linea aspera of the femur is prominent, that the
gluteal ridge is feeble, and no third trochanter was seen in four femora
examined by them. In the Semang femora at Cambridge (Skeat Coll.) the
femora are very slender at their lower ends, herein resembling Bush-native
femora. The tibial head would seem to be retro verted (cf. Fascic. Malay -
enses, I. p. 156).

490

THE MORPHOLOGICAL VARIETIES

[SECT. C

The intermembral index. This index is provided by the skeletons de-
scribed in the publication just referred to ( Fascic . Malayenses, p. 156): the
average from four limbs is there given as 67 • 6. This figure removes the
Semang further than the white races from the anthropoid apes. (Cf.
Chapter xm. p. 331.)

The humero -femoral index. The authors of Fasciculi Malayenses record
figures which provide 69 as the average value of this index in four limbs of
Semangs: and judged by this index the Semangs are further removed from
the anthropoid apes than are the white races. (Cf. Chapter xm. p. 339.)

Skin colour. This is of a dark chocolate-brown, passing through dark
sepia into black.

Hair. The colour is black: in character the hair is woolly, short, crisp
curls being distributed in peppercorn fashion over the head. Chin-hairs are
scanty and a beard is l-arely developed. As regards the presence of a down-
like hair covering on the limbs and trunk, no observations are accessible
at present.

Eyes. The colour is described as black or dark reddish-brown.

Miscellaneous notes. The general features of the physiognomy are
strikingly similar to those of the Central African dwarfs; especially perhaps
in the development of the alae nasi and consequent breadth of the nose,
and in the width of the face. As in the African varieties, the forehead
has often the character termed bombd by the French. The lips are said
to be full and everted, but not thick.

Steatopygia does not occur. To judge from photographs, the extremities
arc delicately formed, and the tracings of feet provided by Messrs Skeat and
Laidlaw exhibit a slight but definite divergence of the axis of the great toe
from those of the smaller toes.

Dwarf Group. I (C).

Name. Aeta.

Stature. 1480 mm.

Distribution. The islands of the Philippine group.

Cranial indices:

Breadth. 79'6 (av. of 4, Crania Ethnioa) to 83'4 (Virchow, Z. f. E.,
1871). In the living 84’7 (18), (Montano), or 87-5—90
(Miklucho-Maclay, Pet. Mitt., 1874, p. 22). Artificial
deformation has however to be taken into account.

Alveolar. In some cases very marked prognathism is seen, but the
value of the alveolar index can not be calculated from
the data available.

Nasal. 53-6 (av. of 3, Crania Ethnica), this shews a moderate

degree of the Platyrrhine character.

Altitudinal. 74'4 ( Crania Ethnica ) to 771- (Virchow, Z.f. E., 1871.)

Cranial capacity. 1419 (av. of 4, Crania Ethnica), the range being fiom
1310 to 1535.

CHAP. XVI]

OF THE HOMINIDAE

491

Cranial description:

(а) General. The skulls are brachycephalic, though not to a very high
degree : the texture is fine and the surface in general smooth.

(б) Cranial portion: the cranial vault is uniformly rounded, and not “ill-
filled ” : the parietal and sphenoid bones join at the pterion.

(c) Facial portion. The nasal bones are of moderate size and taper
upwards: the nasal aperture is of moderate width only: the maxilla is
prognathous, the effect being largely due to prominence of the alveolar
margin (sub-nasal prognathism). The chin is not prominent, but on the other
hand the ascending ramus of the mandible is massive and long. In general,
the characters of the skull are not suggestive of simian affinities.

Only one skeleton appears to be available for examination. Up to the
present a detailed account is still lacking. No information is accessible
regarding the characters of the lumbar vertebrae or of the pelvis, except that
the sacral notch (a simian feature) is well-marked. (Virchow, Z. f. E., 1871.)

Upper limb bones. The radio-humeral index. It is surmised1 that this
index is about 80 on the average : Virchow quotes figures yielding an index
of 78 {Z. f. E., 1871); this shews but a slight simian resemblance, and falls
short of that provided by the Andamanese pygmies, though it is approxi-
mately the same as that of the Semang ( q . v.).

Lower limb bones. The tibia is (in the only skeleton known) platycnemic.
(Virchow, op. cit.) The tibio-femoral index (80, Virchow, op. cit.) does not
provide any special indication.

The humero-femoral index. Virchow’s figures provide an index of 71,
which has no special significance.

The intermembral index. The figures provided by Virchow yield an index
of 70. This shews a greater length of the lower extremities than in most
dwarf races. In this respect the Aeta approaches the Veddah.

Skin. The colour of the skin is compared to dark copper by some writers
(Montano), while others use the expression “sooty -black” (Symes and
Fichte).

Hair. The hair of the head closely resembles that of the Andamanese,
of the Semang, of the Central African pygmies and of the Bush race, in
consisting of small discrete and closely coiled curls distributed over the head in
the manner described as “peppercorn.” The beard is not commonly de-
veloped and herein the Aeta and Semang are closely similar.

Eyes. Jet-black in colour, according to Foreman.

Miscellaneous. From photographs of the Aeta, it appears that the face
is broad, the nose very broad owing to the large size of the alae, the lips
protuberant, but not everted. The general aspect of the Aeta physiognomy
is however less infantile than in the case of the Semang and Andamanese,
suggesting rather the physiognomy of certain of the negro races of Oceania.

The whole subject of the distribution of the Negritoes has recently been

1 Sarasin Brothers.

492

THE MORPHOLOGICAL VARIETIES

[SECT. C

exhaustively discussed by Dr A. B. Meyer of Dresden, so well known from his
researches in Negrito ethnology. The work in question, entitled The
Distribution of the Negritoes, was published by Messrs Stengel and Co. in
Dresden (1899).

Dwarf Group. II.

The next group, the Veddah, differ in such important points from the
preceding pygmy types, that though described in series with these, the
differences must always be kept in mind. The pygmy races already described
agree in the possession of short, curly hair, crania which are either short
or of moderate proportions, and upper limbs which in comparison with the
lower limbs are relatively long (this being an infantile character). They are
all truly pygmy in stature.

But the Yeddah are distinctly taller, and also differ from the foregoing
pygmies inasmuch as their hair is long and wavy, their crania are very
elongated, and their upper limbs are comparatively short. And while they
thus differ from the veritable pygmy races, they agree with certain black
tribes of Southern India, with some of the Sakei of the Malay Peninsula
and, though to a less degree, with the aborigines of Australia. So it seems
probable that the distinction is a real one and that two definite stocks were
here recognisable.

Nevertheless, since so much has been written about the Veddah and so
many simian traits are alleged to occur in their structure, it seems desirable
to treat of them in the present connection.

Name. Veddah.

Stature. 1576 mm. (av. 71 $ )x, 1473 mm. (28 9 ).

Distribution. Ceylon only: allied types occur sporadically in Southern
India, where it is not a little remarkable that genuine “Negrito” aborigines
have not yet been discovered, despite Lapicque’s statements (1904).

Cranial indices:

Breadth. 71 *5 ( «? ), 71‘4(9)- Distinctly dolichocephalic. In living

subjects the index is about 75.

Alveolar. 95'2(c$'), 94T ( 9 ). Distinctly orthognatlious ; but the

teeth are prominent.

Nasal. 52'7 ( £ ), 5L7 (9 ). Mesorrhine ; small simian grooves are

not infrequent.

Height. 74T (£).

Cranial capacity. 1250 c.c. (for $ ) ; 1140 c.c. (for 9 ) : in some women the
capacity of the skull is very small (hardly exceeding 900 c.c.)

Cranial description:

(a) General. Muscular crests and ridges are not well marked: the weight
of the skull is (on the average) 574 gm. in men, 521 gm. in women.

1 Sarasin, Ergebnisse , p. 88 et seq. This work is of the first importance in
connection with the Veddahs.

OF THE HOMINIDAE

493

CHAP. XVI]

(. b ) Cranial portion. The skull is dolichocephalic, the lateral parietes
being flattened, the temporal region not bulging, the foramen magnum not
directed so far forwards as in the white race, and the occipital region less
prominent than in these. The extreme dolichocephalic proportions dis-
tinguish the Veddah very clearly from other pygmy types.

(c) Facial portion. Prognathism is due to the projection of the teeth
only : the orbits are not so vertically flattened as in the other dwarf types :
the palate is of moderate dimensions : the mandible is slight, the chin being
distinctly, though not markedly, prominent.

Lumbar curve. This is koilo-rachic, with an index of 103-5 (av. 8 $ ), but
ortho-rachie (99'9) in women.

Pelvis. This is narrower and higher, and therefore more simian, than
in the white races, the breadth-height index being 80 '9 in men, 78-9 in women
(cf. Europeans, 73). The brim index is 89 '9 for men, 88'2 for women, and
thus platypellic, the type of the most highly .developed Hominidae.

Scapula. The principal feature is the obliquity of the axis of the spine.
The index is greater than in European scapulae. These features are simian.

Humerus. The per-centage (58) of perforated olecranon fossae is very
high.

Femur. The third trochanter is not common ; when present, it is usually
small.

Upper limb bones. The skeletons yield a radio-humeral index of the
following values; for 8 <$ , 79'8 ; for 2 $ 78’8, with a range from 76'5 — 83-4.
The proportions are thus of the same mean value as in the Semang : but when
the figures for the living Yeddah are examined, the indication is seen to lack
corroboration from the skeletal proportions, just as is the case in the data
for African pygmies and for the Semang. The method employed would seem
to be in fault. The index (radio-humeral) for living Yeddah men is 91 '9
on the average.

Lower limb bones. The tibia is not platycnemic : the tibio-femoral index
is 86-l (for 7 ), or 84'7 (for 3 <j? ). These figures indicate simian tendencies.

The humero-femoral index appears from the measurements of the
Sarasins to be about 71, which is not very different from those of the white
races, though far below (i.e. the humerus is far shorter than that of) the
Central African pygmies.

The intermembral index. The average values for this index are 68-7 or
69T (7 c? ), 67 or 67'4 (for 2 9 ) according as the tibial spine is included or
not in the measurement: no simian resemblance can be detected here, and
further the proportion does not indicate an infantile trait ; in this respect
the Veddahs are to be distinguished from the infantile type of dwarf.

Skin. The skin-colour varies from tribe to tribe, and even in one and
the same individual the tint is not uniform throughout the whole extent
of the body. No less than twelve tints have been described, but it is
noteworthy that while a variety of browns from “yellowish-brown” through
“reddish-brown” to “dark-brown,” are mentioned, in no case and in no
region is the skin jet-black.

494

THE MORPHOLOGICAL VARIETIES

[SECT. C

Hair. The hair is coarse, wavy, not woolly, uniformly distributed over the
head, not “peppercorn” and always black. The beard is scanty and so is
the distribution of hair on the body generally. A few individuals have rather
hairy legs.

Eyes. The colour is described as black-brown or dark-brown (Nos. I
and II of Broca’s tables).

Miscellanea. The brothers Sarasin, who have so extensively investigated
the characters of the Veddah, give the following list of characters in which
this race presents simian affinities, as compared with the white races.

(1) The proportionately larger development of that part of the skull
which lies anteriorly to the auditory meatus.

(2) The greater downward growth of the frontal bone on the inner
orbital wall.

(3) Small stature and cranial capacity.

(4) More upright cranial walls.

(5) More flattened contour of cranial vault.

(6) Great proportionate length of fore-arm as compared with arm.

(7) Greater frequency of perforation of the olecranon fossa humeri.

(8) Greater frequency of junction of squamous bone and frontal bone in
the region of the pterion.

While against these must be placed the greater elongation of the lower as
compared with the upper limbs.

Dwarf Group. III. Prehistoric Pygmies of Europe.

In interments referred to the neolithic period at Schweizersbild in
Switzerland, Kollmann found remains of human beings of pygmy stature.
Some of the chief features of these skeletons are reviewed in the following
notes :

Stature. Three skeletons are considered to be those of mature women, and
the average stature computed from the femoral length is stated by Kollmann
to be 1424 mm. (cf. female Veddah, 1433 on the average), Pearson’s calcula-
tions reducing this figure to an average of about 1410 mm.1

1 The last-named observer applying the most elaborate methods to the deter-
mination of stature from measurements of long bones of the skeleton, has arrived
at the following results for various pygmy races.

Male.

Female.

Andamanese,- 1st series ...

1492

... 1403.

2nd series ...

1470

... 1443.

Bush race, 1st series ...

1444

... 1404.

2nd series ...

14G0

... 1420.

Akka dwarfs ...

1200

... 1240.

Aeta ,,

1441

... 1384.

Veddah ,, ...

1530

... 1433 (?),

which differ slightly from the results given in the foregoing notes.

CHAP. XYl]

OF THE HOMINIDAE

495

Crania. These are small and ovoid, the average capacity being 1120 (2)1
and the breadth index 69 (2) ; muscular ridges are not distinctly shewn : as
regards prognathism, no direct evidence is forthcoming, but it does not
appear that this was a marked feature : in fact the narrowness of the face,
which is distinctly cited, tends to shew that these pygmies were not pro-
gnathous.

Limb bones and other parts of the skeleton. Only the tibio-femoral (80)
and the humero-femoral indices (67 '6) can be calculated : no simian affinities
are indicated hereby.

The chief characters of importance would seem to be the narrowness of
the skull, which distinguishes these pygmies from such existing pygmy races
as the Aeta, Semang, Andamanese, or Central African.

1 The figures in brackets indicate the number of examples observed.

SECTION D.

PALAEONTOLOGY.

CHAPTER XVII.

FOSSIL Pill MATES.

Having concluded enquiries into the Comparative Anatomy, the
Embryology, and the Morphological Variations of the Hominidae, it
remains to examine the evidence of Palaeontology (the Comparative
Anatomy of extinct forms), with a view to ascertaining the bearing
of this evidence on the question of the relations of the Hominidae
to other Eutheria. As has already been indicated (Chapter I. p. 11),
the study of the fossil remains of extinct animals has in certain
instances provided most striking evidence as to the evolution of
modern forms, and has revealed the former existence of animals
which link together groups now separated in appearance and
morphological characters. The often-cited example of the Equidae
may be mentioned as illustrative of the value of palaeontological
research in the former instance, and the discovery of such inter-
mediate forms as Archaeopteryx (which unites Reptiles and Birds),
of Arctocyon, possessed of a combination of characters, some of
which become intensified on the one hand in the Canidae, others
again in the Ursidae of modern times, or of the fossil Lagomorpha,
which1 represent the parent-forms common to modern hares and of
squirrels, are illustrative of the value of palaeontology in revealing

1 Cf. Forsyth-Major, Linnaean Transactions, 1895.

CHAP. XVII]

FOSSIL PRIMATES

497

links which would have otherwise remained missing had observa-
tions been directed to living forms alone.

With such objects in view, it is here appropriate to submit
a series of brief descriptions of fossil Primates ; at the same time,
it must not be forgotten that from a priori considerations (cf.
Chapter n. p. 26) such forms may be described as “ marginal ” ;
that is to say, their characters will not in all instances agree with
those conventionally laid down as the necessary qualifications for
admission into the Eutherian Order Primates, as constituted in
the present geological epoch. With these introductory considera-
tions, we may now proceed to a review of the characters of the
following fossil forms.

Sub-order

. Lemuroidea : —

Megaladapis.

II.

Adapis.

III.

Anaptomorphus.

IV.

Nesopithecus.

Sub-order. Anthropoidea : —

Family.

Cebidae.

Homunculus.

Family.

Cercopithecidae.

YI.

Oreopithecus.

VII.

Mesopithecus.

Family.

Simiidae.

VIII.

Pliopithecus.

IX.

Palaeopithecus.

Pliohylobates.

XI.

Dryopithecus.

XII.

Anthropodus.

Family.

Pithecanthropidae.

XIII.

Pithecanthropus.

Family.

Hominidae.

XIV.

H. primigenius
(seu neanderthalensis).

FOSSIL LEMUROIDEA.

I. Megaladapis. Gigantic lemurine animals, the remains of which occur
in recent (Pleistocene) swamp-deposits in Madagascar. Several species are
distinguished : in size they surpassed a St Bernard dog.

The Skull (cf. Fig. 305) bears a general resemblance to those of recent
Lemurs, but is much larger and bears much more prominent temporal ridges.
The two halves of the mandible are synostosed at the symphysis. From the

D. M.

498

FOSSIL LEMUROIDEA

[SECT. D

examination of a cast of the endocranial cavity, Elliott Smith1 concludes that
the olfactory bulbs were borne on elongated stalks, and that the disposition
of the cerebral convolutions resembled those of modern Lemuridae.

Fig. 30/5. Cranium, with mandible, of Megaladapis insignis, a gigantic extinct
Lemur. The upper inciBor teeth are vestigial.

The teeth 2. It was at one time thought that no upper incisor teeth were
retained in the adult skull: but they seem to be present, though vestigial,
in M. insignia (cf. Fig. 305). The upper premolar teeth (cf. Fig. 308) bear
external and internal (lingual and labial) cusps. The upper molar teeth
(cf. Figs. 306 and 309) bear one internal and two external cusps. In the

Fig. 306.

Fig. 307.

Fig. 306. Scheme of cusps of the upper molar teeth of Megaladapis. The two
anterior cusps are connected by a transverse ridge, leaving the postero-external cusp
isolated.

Fig. 307. Scheme of cusps of the lower premolar teeth of Megaladapis. The
antero-external and postero-internal cusps are connected by a ridge. The third or
intermediate internal cusp is minute in size.

1 Cat. Mus. Hoy. Coll, of Surgeons, 1903.

2 v. Lorenz, Denk. Akad. Wins. Wien. Bd. nxx. 190, PI. i, Fig. 11.

FOSSIL LEMUROIDEA

499

CHAP. XVII]

mandible the last premolar tooth bears one external (labial) and three
internal (lingual) cusps (cf. Fig. 307). The molar teeth are provided with
two external and three internal cusps, the third tooth of this series being
provided with a “talon1.”

Fig. 308.

Fig. 309.

Fig. 308. Canine and upper premolar teeth (upper jaw, right side) of an extinct
gigantic Lemur, Megaladapis insignis.

Fig. 309. Teeth of upper (to the left) and lower series of an extinct gigantic
Lemur, Megaladapis madagascariensis.

With regard to other parts of the skeleton, the remarkable flattening of
the shafts of the humerus, ulna and femur, with flange-like lateral projec-
tions, must be noted. Platymeria of the femoral shaft is thus distinct.
(Cf. p. 53, footnote ; also p. 315.)

Forsyth-Major2 notes that the femoral shaft is curved, with the concavity

1 Specimens of the teeth and skulls of Megaladapis are exhibited in the Natural
History Museum, South Kensington. Other specimens are in the Imperial Museum
at Vienna.

2 Geological Magazine, Nov. 1900, p. 494.

32—2

500

FOSSIL LEMUROIDEA

[SECT. D

forwards. In these respects Megalaclapis anticipates the characters of the
modern Potto (Perodicticns) of West Africa; and since in the latter
animals locomotion is sluggish, it is suggested that the Megaladapidae were
also thus characterised, and that they were not tree-climbers like most Lemurs
of recent times.

II. Adapis. (Cf. Fig. 310 A.) Fossil lemurs found in W. Europe
(Eocene strata in France), and in N. America. As an example, the genus
known as Hyopsodus may be considered. (The cranium shewn in Fig. 310 A,
is that of Adapis parisiensis.) The skull has no post-orbital bar and the
lacrymal foramen opens marginally, or within the orbit1.

Fig. 310. Crania of (A) Adapis parisiensis, a fossil Lemur ; and (B) Lemur varius,
a typical modern Lemur. The crania are closely similar in form. (Mils. Zool.
Gant. W.L.H.D. del.)

The teeth. The dental formula is extremely primitive (and in fact realises
the original formula proposed by Oldfield Thomas as that of the stem-form

Fig. 311. Scheme of the cusps in an upper molar tooth of Hyopsodus. The
posterior lingual cusp is the smallest and is inconspicuous in the last upper molar
tooth.

Fig. 312. Scheme of the lower molar cusps in Hyopsodus. The oblique ridge
connects the antero-internal (lingual) and postero-external (labial) cusp.

Fig. 311,

Fig. 312.

1 Osborn, Bull. Am. Mus. Nat. Hist., Vol. xvi. Art. xvii, p. 179.

CHAP. XVII]

FOSSIL LEMUROIDEA

501

of the Mammalia)1: 112: i, f; c, } ; pm, m, %. • In the upper jaw the
molar crowns are nearly square, the transverse and antero-posterior diameters
being nearly equal. The cusps vary in number, three or four being usually
present. (Cf. Fig. 311.)

The lower molar teeth bear four cusps, and these are joined by ridges,
disposed as in Fig. 312 : a talon is sometimes present.

The incisor teeth are not procumbent as in recent lemurs, but vertical2 as
mentioned above. (Cf. p. 153.)

Of the skeletal parts other than the skull, the humerus is the most
important. Forsyth-Major ( Geol . Mag. loc. cit.) considers that it closely
resembles the humerus in the Lemuridae (exception being made in the case
of the group known as the Indrisinae).

III. Anaptomorphus. Family Anaptomorphidae. The constitution of
this Family is based on evidence derived from the study of six mandibles, one of
which is accompanied by the skull : the Anaptomorphidae were small lemurine
animals, and are noteworthy as occurring in North America, in strata referred
to the Eocene period3.

The position of Anaptomorphus has been the occasion of much discussion,
one of the chief points at issue being the question as to whether it is more
closely allied to the Lemurs, or to that aberrant Primate-form Tarsius, which,
while resembling the Lemurs structurally in many ways, yet is distinguished
absolutely from these by its placental form. Judged by the skull, Anapto-
morphus is allied to the Lemurs4. In the reduplication of the infraorbital
foramen, the affinity is with a member of the Cebidae, viz. Chrysothrix.
"When the characters of the teeth are regarded, Anaptomorphus is considered
to resemble Tarsius and the Hominidae, the molars bearing three cusps
(tritubercular5), except the first and second lower molars ; whereas the
modern Lemurs and the Adapidae (cf. II. Hyopsodus) are provided with
molars bearing four cusps. Osborn gives the dental formula as ( i ; c ;
§, pm ; |, m. And in one mandible only two instead of three premolars occur.
The skull is very small (only about 20 mm. in length), and superficially
resembles that of Tarsius. It is noteworthy that Anaptomorphus closely
resembles another fossil Eutherian, viz. Mixodectes, which though at first
placed among the Primates, is now considered as rather belonging to the
Order Rodentia. We here meet with forms which serve to bridge the gap
between two modern Eutherian orders.

1 Vide Chapter vi. p. 150, for a revision of this formula; also Woodward,
Vertebrate Palaeontology, pp. 404, 406.

2 Cf. Woodward, Vertebrate Palaeontology , p. 405.

3 Cf. Osborn, Bulletin of the American Museum of Natural History, Vol. xvi.
Article xvii. 1902, p. 199 et seq. Also Hubrecht, The Descent of the Primates.

4 Osborn, op. cit. p. 201, characters of the lacrymal bone.

6 Cf. Chapter vi.

502

NESOPITHECUS

[SECT. D

IV. Nesopithecus. This is the generic name given to a number of
species found in the fossil state in recent marsh deposits in Madagascar1.
About four crania and mandibles, more or less imperfect, are known, as well
as other skeletal remains. The special claim on our interest possessed by
Nesopithecus depends on the conclusion reached by Forsyth-Major, to the
effect that the morphological characters confer on this genus a position
intermediate between the Lemuroidea and Anthropoidea. Among the groups
of characters laid down by Forsyth-Major as a result of his researches on
Nesopithecus, the following are the most important.

1. Primitive characters which Nesopithecus shares with Adapis (cf. II.)
and with certain of the Lemuridae ; the cerebellum is not overlapped by
the cerebrum ; there is a large tympanic bulla ; there is no postorbital wall ;
the lower canine is posterior to the upper caniniform tooth2, the humerus has
an entepicondylar foramen.

Fig. 313. Teeth (A, the upper B, the lower series) of Nesopithecus, an
extinct primate mammal intermediate between Lemurs and Apes. Hie owu
incisor teeth are spatulate, the molar teeth (except in the last) bear four cusps,
and the last molar tooth has but three cusps. The teeth are ape-like lather lan
lemuroid. The upper molar teeth were probably tri tubercular. (From a specimen

in the Natural History Museum, South Kensington.)

1 The specimen first discovered was designated N. roberti.

2 The exact nature of this tooth is in dispute.

CHAP. XVII]

FOSSIL ANTHROPOIDEA

503

2. Simian characters, not present in Lemuridae, and which Nesopithecus
shares exclusively with the Anthropoidea, and particularly with the Cerco-
pithecidae : voluminous brain, with cerebral convolutions arranged similarly
to those of Anthropoidea ; “ steep ” facial profile ; orbits directed forwards ;
nasal duct opening within the orbital margin ; conformation of the upper
median incisors ; number of the lower incisors. In the Proceedings of the
Linnean Society (March 5, 1903), Professor Elliott Smith in describing the
endocranial cast of Nesopithecus (which is figured in the publication in
question) makes the following important remarks : “ The shape of the brain
and the disposition of its furrows in Nesopithecus are therefore much more
pithecoid than those of any other Prosimian (Lemuroid) ; and in Forsyth-
Major’S words, it departs from the Lemuridae, and approaches the Cebidae
and Cercopithecidae.” ( Proc . Roy. Soc. 1898, Yol. lxii.)

3. The limb bones possess characters intermediate between those of the
Lemuridae and Anthropoidea.

4. Characters special to Nesopithecus : these refer to the teeth, the pre-
molars being “blade-shaped.” (Cf. Fig. 313, A and B.)

FOSSIL ANTHROPOIDEA. While fossil Lemuroidea occur in Eocene
formations, both in Europe and N. America, the Anthropoidea appear in the
Eocene strata of the latter geographical area only ; in Europe they make
their appearance only in Miocene deposits, i.e. at an epoch posterior in time
to the Eocene. A few forms of Hapalidae and Cebidae are recorded as
having been found in Pleistocene deposits in caverns in Brazil, but these are
less interesting than the fossils belonging (it is claimed) to the Eocene strata of
Patagonia, and described by Ameghino1. Four genera have been proposed
for these fossil apes of the Family Cebidae : they agree in being of small size,
platyrrhine, and in the possession of thirty-six teeth, like the modern Cebidae.
(Cf. Chapter in.) Only one genus, viz. Homunculus, will be considered here.

V. Family Cebidae. Homunculus patagonicus. The mandible is long
and very narrow : the premolar teeth are tricuspid, but with one root only :
they bear one external, and two internal cusps. The molar teeth are tetra-
cuspid, with two external and two internal cusps ; and the first molar is
smaller than either the second or the third.

Ameghino has suggested that the occurrence of these Anthropoidea, at
such an early epoch as the Eocene period in the New World, gives support
to the view that the Hominidae were evolved in that geographical territory.
But the suggestion is not strongly supported, and it is a matter of regret
that the generic names selected for these Cebian fossils should suggest special
human relations which have no great weight of evidence to support them.

1 The name of this celebrated palaeontologist should be added to the list of
those who dissent from the tritubercular theory of the evolution of the molar
teeth in the higher Eutheria. Vide Ann. Mm. Buenos Ayres, s6r. 2, vol. hi. ; reviewed
by Lydekker, Nature, July 28, 1904.

504

FOSSIL ANTHROPOIDEA

[SECT. D

VI. Family Cercopithecidae. Oreopithecus. A genus created for
animals represented by fossil remains of Miocene age found in Tuscany.
The upper molar teeth bear four cusps, viz. two external, and two internal,
sepai ated by a sagittally placed furrow (Fig. 314); the cingulum is strongly
marked.

Fig. 314. Scheme of an upper molar tooth of Oreopithecus : the cusps are four
in number, and there is a sagittally-directed groove.

Fig. 315. Mandible of Oreopithecus bamboli (an extinct monkey from Italy,
resembling the Cercopithecidae) : the molar teeth have a distinct “ talon ” bearing
one or, in the last tooth, two cusps.

The crowns of the lower molars bear five cusps 1, the fifth being posteriorly
situated on the backward prolongation or “talon.” (Cf. Fig. 315.)

Oreopithecus bamboli is regarded by some writers as intermediate in
characters between the Cercopithecidae and the Simiidae ; Flower and
Lydekker regard it as the ancestral form which gave rise to the living
Simiidae.

VII. Family Cercopithecidae. Mesopithecus (pentelici). Numerous
specimens, chiefly crania, mandibles, and a few of the stouter long bones,
have been obtained in the deposits at Pikermi in Attica. Gaudry, who first
described this species, regarded it as intermediate between the existing genera
Cercopithecus and Semnopithecus. The figures (316, 317 a, 317 b) represent
the skull (from a cast in the University Museum of Zoology) and the teeth
1 Kramberger (quoted by Klaatsch, Anat. Hefte, 1902) has suggested that each
molar tooth has been derived, by fusion, from five cone-like teeth. Klaatsch
evidently sees difficulties in the way of this hypothesis, for which no strong support
is forthcoming.

CHAP. XVII]

FOSSIL ANTHROPOIDEA

505

in a young jaw (from a specimen in the Natural History Museum South
Kensington). Better preserved specimens (at Paris) bear transverse ridges
like those of modern Cercopithecidae. The femoral shaft was curved with
anterior convexity.

Fig. 316. Cranium, with mandible, of Mesopithecus pentelici, an extinct Euro-
pean (Greek) monkey. The general characters resemble those of the Cercopithecidae.
(Cf. Fig. 28.)

Fig. 317. Teeth of Mesopithecus pentelici ; A, lower left series (the premolars
and molars are shewn ; B, the upper right series ; only the molar teeth are repre-
sented.

Family Simiiclae.

VIII. Pliopithecus (antiquus). Represented by upper and
lower jaws from various Miocene deposits over a wide area of
Europe, viz. from the Pyrenees to Styria : the two rows of teeth
(premolar and molar series) diverge posteriorly : the molar crowns
are narrow and elongated : in the former character Pliopithecus
differs from, and in the latter it agrees with, the form known as
Dryopithecus, ( v . infra ) : on the whole, Pliopithecus is believed to
be most closely allied to Hylobates among living Simiidae, and
from the latter it is stated by Flower and Lydekker to be indistin-
guishable. It is however to be noticed that Dubois disputes this1.

1 For a critical review of recent literature on the fossil Simiidae, cf. Max
Schlosser, Zoologischer Anzeiger, Bd. xxm. No. 616. May 28, 1900 : abstracted by
W. L. H. Duckworth, J. A. and P. Vol. XXXV.

506

FOSSIL ANTHROPOIDEA

[SECT. D

IX. Palaeopithecus1 2 sivalensis. Represented by a fragmen-
tary upper jaw from the Sivalik hills, N. Hindustan, in strata of
either Miocene or Pliocene age. Possibly a fossil tooth attributed
by Falconer to the Orang-utan, and found in the same deposits,
was really referable to Palaeopithecus : but no verification of this
suggestion is possible. Lydekker considered Palaeopithecus to be
a Chimpanzee : but Dubois places it lower among the Simiidae,
and in fact isolates it on the grounds of the narrowness of the
palate and the parallelism of the rows of teeth on either side
of the jaw.

The molar teeth (Fig. 318) have no crenate markings : but this
would separate Palaeopithecus from
Anthropopithecus (Chimpanzee)
almost as effectually as from Simia
(Orang-utan) among living Simiidae.

The narrowness of the palate has
already been remarked : it is nar-
rower than in any anthropoid except
Gorilla and Dryopithecus, and the
molar teeth are said to be very
human in appearance. Flower and
Lydekker state that “ all essential
characters of Anthropopithecus
(Chimpanzee) are present : the two
series of cheek teeth have a slight
anterior convergence1* ; ” the premo-
lars are shorter in sagittal diameter,
and the lateral incisors are narrower
than in Anthropopithecus.

X. Pliohylobates3 (eppelshei-
mensis). This species is based on
(a) the characters of a single femur,
found in strata of Miocene age in
the Rhine-valley at Eppelsheim, near Darmstadt, and ( b ) portions

A B

Fig. 318. Teeth of Troglodytes
sivalensis, an extinct anthropoid
ape (Simiidae) ; A , upper rightseries;
the molar teeth were probably four-
cusped ; the last tooth is degenerate
in point of size. B , second left
upper molar tooth.

1 Or, Troglodytes.

2 This does not agree with Dubois’ view.

3 Or Paidopithex ; cf. Pohlig, Bull. Soc. Belg. 06ol. Vol. ix. 1896, p. 149, 1'igs. 1
and 2 : also Kaup, Bcitr. zur Snug. 1861, Heft 6, Fig. 1.

FOSSIL ANTHROPOIDEA

507

CHAP. XVII]

of three mandibles, found in France and Germany respectively.
The former specimen has been the cause of much discussion, and
inasmuch as it was discovered some sixty years ago, it has
attracted the attention of a considerable number of authorities.
The following notes will give an indication of the opinions that
have been put forward concerning its affinities.

(1) It has been ascribed to a human being (a young female).

(2) It has been regarded as belonging to an ape of the same
species as yielded a fossil humerus found at S. Gaudens in France ;
the latter form was described as a fossil Hylobates (Gibbon) by
Owen, under the name of Dryopithecus fontani.

(3) It was then pointed out, (a) that the strata at S. Gaudens
are not of the same geological age as those of Eppelsheim, ( b ) that
the argument from femur to humerus was not a very safe one, and
(c) that therefore judgment must be suspended before identifying
the fossil apes of S. Gaudens and of Eppelsheim.

(4) It might be a femur of Pliopithecus (q.v.), but of the
latter only the maxillae are known.

(5) Dubois separates the possessor of the Eppelsheim femur
from all the foregoing, and describes it, under the title Pliohylobates,
as an ancestral form of Gibbon. The length of the bone (284 mm.) is
too small for a human femur : the presence of a linea aspera, though
a human feature, does not exclude the possibility of its being that
of a Gibbon, and Dubois concludes that Pliohylobaoes exceeded by
l the bulk of the largest existing form of Gibbon.

The mandible and teeth resemble those of existing Gibbons.

XI. Dryopithecus (fontani). Represented by about four
mandibles and a humerus, from strata of Miocene age (but not con-
temporary with the Miocene of Eppelsheim) at S. Gaudens in France.

The molar teeth, Fig. 319, bear crenations on their crowns not
unlike those of the molar teeth of Orang-utan and Chimpanzee.
Flower and Lydekker state that the mandibles resemble those of
Gorilla, inasmuch as the two lower molar series of teeth diverge
anteriorly, while the first premolar exceeds the second in size : on
the other hand, the mandibles differ from those of the existing
Simiidae, in the possession of a long and narrow symphysis, this being
a character by which they are approximated to the Cercopithecidae.

508

FOSSIL ANTHROPOIDEA

[SECT. D

It is to be noted that the characters of the first mandible found
led to the conclusion that Dryopithecus was an anthropoid ape
more highly evolved than any of the existing Simiidae, and thus

Fig. 319. Mandible (A) and teeth (B and C), of Dryopithecus fontani, an extinct
anthropoid ape resembling the Chimpanzee (Simiidae). G represents diagram-
matically the number and disposition of the dental cusps: the transverse ndges
resemble those prevalent in the Cercopithecidae.

FOSSIL ANTHROPOIDEA

509

CHAP. XVII]

one of the links between the Simiidae and Hominidae1 : but the
discovery of other mandibles did not support this view, appeals
being made principally to the characters of the molar teeth (i.e.
the proportions of sagittal and transverse diameter ; and the
incurving of the external posterior cusps). Judged by the form
of the molar teeth, Schlosser would derive the modern Orang-utan
and Chimpanzee from Dryopithecus, which is thus regarded as
ancestral to these, but not to Gorilla or the Hominidae.

On the other hand, Flower and Lydekker suggest that the transi-
tion has been from Dryopithecus to Gorilla, Anthropopithecus and
the Hominidae in succession. Pohlig gives the succession as Orang-
utan, Chimpanzee (and Gorilla), Dryopithecus, Homo : and against
this we find Gaudry postulating the sequence as Dryopithecus,
Gorilla, Orang-utan (with Gibbon and Pliopithecus), Chimpanzee,
Homo. From the characters of the mandible and humerus (the
latter had not retained its terminal epiphyses), an attempt was
made to decide as to whether Dryopithecus was more like the
Gibbons, or whether its length of arm was less than in these. The
humeral length, in comparison with the length of the dentary
arcade, is too short for the proportions to resemble those of modern
Gibbons.

It must be admitted that judgment is not easy to pronounce
at present, and the recent discovery of certain teeth in the Bohnerz
ore in S. Germany2 3 renders a decision even harder than before, for
the latter teeth, though attributed to Dryopithecus, admittedly
resemble human teeth very closely, and but for their occurrence
in Miocene strata would probably have passed as of human origin.
Two new species of extinct anthropomorphous apes are based upon
the characters of molar teeth found in the calcareous Leitha
formation in Austria (Vienna). To these forms the names Gri-
phopithecus suessi and Dryopithecus darwini have been given
by Abel2. The characters of these teeth present the same dif-
ficulty of identification as is provided by the fossils previously
described.

1 Gaudry, quoted by Schlosser, Zool. Anz. No. 616, p. 297.

2 Of- v- Branco, Jahreshefte des Vereins filr vaterldndische Naturlcunde in
WUrttemberg , 1898.

3 Centralbl. fur Mineral. Geol. etc. 1903.

510

FOSSIL ANTHROPOIDEA

[SECT. D

XII. Anthropodus brancoi. In view of this difficulty
Schlosser1 has created a new genus and species for the reception
of the possessor of the teeth from the Bohnerz; this is now
distinguished as “Anthropodus brancoi.” It must be remarked,
nevertheless, that while Schlosser recognises the close affinity of
Anthropodus (brancoi) with Dryopithecus (fontani), and the further
close resemblance to the Hominidae, he comes to no definite con-
clusion as to the genetic relationship of Anthropodus and the
Hominidae4. (Cf. Schlosser, Zool. Anz. 616, p. 264.)

XIII. Family Pithecanthropidae. Pithecanthropus (erec-
tus). This genus is represented by a single individual, skeletal
portions of which were discovered in strata referred to the Pliocene
series, in Java at Trinil, by Eugene Dubois of Amsterdam in
1892-4. The announcement of this discovery and the conclu-
sions as to the nature of the fossil form, which have been based
on the study of the remains in question, have aroused a storm of
controversy, in the course of which the most diverse opinions have
been expressed. Incidentally, too, the controversy has been the
means of stimulating some admirable researches in physical an-
thropology4. Dubois published his first descriptions at Batavia in

1 Zoologischcn Anzeiger, Band xxiv. No. 643.

2 Gaudry notes (Complex Ren dux : Congres d' Anthropologic ct d’Arch. pr6hist.
1900, p. 39) the general tendency in the palaeontological series to a transition
from the tricuspid to the quadricuspid type of upper molar tooth. This tendency
is noticeable in several orders of Mammalia, and the Hominidae have now reached
a stage attained by many of these in the early Tertiary epoch. The quadricuspid
type of molar tooth has not been perfectly acquired, inasmuch as the postero-
internal cusp it still feeble and indistinct. This indistinctness is chiefly character-
istic of the European white races, for the cusp in question is more prominent in the
negro races, and also in Anthropopithecus and Ilylobates (though in Simia there is
again indistinctness). Passing back to fossil Simiidae and Cereopithecidae, in
Dryopithecus and Oreopithecus the cusp is still more evident. Two hypotheses are
thus open : (a) that in the white races, this molar tooth is degenerating from a
stage of development which reached its highest point in the Dryopithecus phase of
human ancestry ; or (b) that the white Hominidae have not advanced in the evolution
of the upper molar teeth beyond the stage reached by their forerunners in the earlier
Tertiary period (Eocene). While the author does not suggest which of these
hypotheses is the more worthy of adoption, the balance of evidence favours (a), so
that we may conclude that degeneration has set in, and indeed it is not difficult to
find evidence of the continued activity of this process.

3 The literature is now very extensive. Dubois published several supplementary
memoirs in the years 1895-1900 ; the pages of the Arcliiv fllr Anthropologic,

PITHECANTHROPUS ERECTUS

oil

CHAP. XVII]

Java in 1894. Fossil remains of the Primates are sufficiently
rare to attract a certain amount of attention independently of their
exact relation to the Hominidae. But the interest here aroused
was unusually intense, inasmuch as Dubois claimed for the Trinil
fossil, a position intermediate between the Simiidae and Hominidae,
i.e. the position of a link hitherto missing in human ancestry— the
pithecoid ancestor postulated by Lamarck, Darwin, and Huxley
— the Homo alalus of Haeckel.

Current opinions formed subsequently to inspection of the
actual fossils, are divisible into three main classes, which are
represented by almost equal numbers (and curiously enough, in
two of the three cases, the authorities are distinguished in
nationality as well as in opinion). First, then, come those who
following the lead of Dubois, consider that a human ancestor,
not yet wholly human, and yet superior to the Simiidae, is re-
presented by these Javan remains. Secondly, come a number of
human anatomists, including most of the leaders in that subject in
England, who have recorded their testimony in favour of the truly
human nature of the Trinil fossil. Thirdly, come those (for the
most part German observers1) who believe that the Pithecan-
thropus erectus was a large Hylobates, and as such, a member of
the Simiidae ; for these authorities, the remains are neither2 those
of an intermediate form, nor of a human being, but of a veritable ape.

Zeitschrift fur Ethnologie, Bulletins de la Societe d' Anthropologie de Paris, Ana-
tomischer Anzeiger, and the Journal of Anatomy and Physiology for the year 1895, will
supply the most important references. Most important communications on the
subject also appeared in Schwalbe’s Zeitschrift f Hr Morphologic und Anthropologie
1899, et seq.

1 It must be noticed that in Germany there are anatomists of the first rank, e.g.
Schwalbe and his pupil Klaatsch, who have adopted and confirmed the view of
Dubois.

2 The following list (which is not complete) shews the composition of the fore-
going groups :

I. Adopt the view that Pithecanthropus erectus is an intermediate form.
Dubois, Manouvrier, Marsh, Haeckel, Schwalbe. Klaatsch, so far as I understand
his opinion, regards Pithecanthropus erectus as an intermediate form, but not as
ancestral to Man.

II. Adopt the view that Pithecanthropus erectus is to be regarded as truly
human. Turner, Cunningham, Keith, Lydekker, Martin.

III. Adopt the view that Pithecanthropus erectus is to be regarded as purely
simian. Virchow, Krause (for the calvaria), Waldeyer, Ranke, Bumiiller.

512

PITHECANTHROPUS ERECTUS

[SECT. D

Incidentally it is interesting to note that several of those who
adopt the view of the human nature of this fossil animal, qualify
their belief by admitting that it is far inferior to any known
human form, whether fossil or recent. And, conversely, those
who believe that we have here to do with an ape, in turn
concede that this was morphologically superior to any known
member of the Simiidae, whether extinct or still existing. A
better illustration of the difficulties of defining in detail an animal-
form, when the criteria are limited, could scarcely have been
selected, and the lines which demarcate the several opinions just
mentioned, are seen to be excessively finely drawn. The opinion has
been expressed that the remains are those of a human idiot of the
type known as “microcephalic1,” but besides the consideration that
the chances of the preservation of such an individual in a fossil
state are infinitely small, the characters of the bones do not
support this view. To the study of those characters it is now
time to turn.

The remains consist of : first a calvaria, or upper portion of a
cranium; secondly a (left) femur; thirdly, three teeth, viz. the second
and third upper molars, and the lower second premolar of the left
side. The order here observed is not that in which the remains
were discovered, and the discoveries were made at various epochs
separated by months and even years, for the last mentioned tooth
was found long after the other remains. For details of the
circumstances attendant on the actual discoveries, reference should
be made to the original publication. Here we are concerned to
review the principle features of the several specimens : and these
will be considered in the order given above.

The Calvaria (Figs. 320 and 321). This is the upper portion
of a skull of large proportions : in extreme length it measures
185 mm., in breadth 130 mm., and consequently its breadth index
is 70 (approximately). The index of height is much lower, the
small vertical height of the calvaria being a very distinctive feature.
The bones of the vault have all been united, synostosis having
obliterated the sutural lines completely, and though there is no
such sharp median sagittal ridge (as in the crania of adult male

i Cf. pp. 448—450.

PITHECANTHROPUS ERECTUS

513

CHAP. XVII]

Simiidae of the larger genera), yet in the frontal region the skull
vault is slightly keeled, reproducing locally the condition known as
scaphocephalus1.

Fig. 320. The calvaria of Pithecanthropus erectus seen from above (1 nat. size).

Fig. 321. The calvaria of Pithecanthropus erectus seen from the side (J nat.
size).

The brow-ridges of the Trinil calvaria are massive2, and
posteriorly to them the diameter of the skull is relatively small,
so that the appearance of post-orbital “compression” is very
marked. Such “compression” should rather be termed arrested
growth, and the appearance is very characteristic of the larger
Simiidae, in which the jaw is very ponderous, and the mass of
temporal muscle that has to be accommodated in the temporal
fossa is very great. No very prominent ridges traverse the
surface of the calvaria, whether on the upper or on the nuchal
aspect: the latter part is nearly complete, and the posterior
margin of the foramen magnum can still be recognised. This
posterior or occipital surface slopes forward, with relatively little
obliquity, and this portion of the skull is attenuated in develop-
ment as compared with the corresponding portion of a human
cranium. At the same time, there is a slight but distinct
indication of that bulging of the occipital bone found in many

1 Such a condition is said to characterize human crania in which the synostosis
of the two halves of the frontal bone has been premature ; the transverse growth
of such human crania is often arrested with the production of an abnormal skull-
form called Trigonocephalus.

2 Comparison is naturally suggested with the heavy-browed scaphoid and pro-
gnathous skulls of certain aborigines of Oceania and of Australia. But these human
crania differ from that of Pithecanthropus erectus in the much bolder curve of the
sagittal arc, and the greater rotundity of the occipital region.

D. M.

514

PITHECANTHROPUS ERECTUS

[SECT. D

dolichocephalic human crania. This bulging, to which the term
renflement occipital has been applied by French writers, may be
indicative of the presence of a well-marked sulcus lunatus in the
cerebral hemispheres covered by such crania1.

Considering (for the moment) the calvaria on its own merits, we
shall notice that there are several strongly marked simian features.
Such for instance are :

(1) The completeness of synostosis of the component bones of
the cranium.

(2) The massive brow-ridges.

(3) The post-orbital compression.

(4) The low flattened curve of the sagittal arc of the cranium.

Fig. 322. Tracing of the calvaria of Pithecanthropus erectus, to shew the angle
included by the nuchal plane (N), and the Glabello-opisthionic line (Gl-Op). N'
represents the inclination of tnc nuchal plane in Hylobates (Simiidae), and N" the
corresponding inclination in a Papuan skull (Hominidae) : the latter specimens were
orientated similarly, i.e. with the glabello-opisthionic line corresponding in position
to the calvaria of Pithecanthropus erectus.

Against these are to be placed the following items which
differentiate the calvaria from those of the Simiidae, approximat-
ing it to those of the Hominidae.

(1) The great absolute size and capacity: the latter is
estimated at 855 c.c., and is thus greater by about 250 c.c. (or over
30°/o) than the corresponding figure for the largest skull of the
Simiidae.

(2) The associated brain-weight, estimated at 750 gin.

(3) The distinctness of the third frontal convolution. This
argument urged by Dubois must however be largely discounted in
view of the researches of Cunningham and Elliott Smith on the
development of this convolution in the Simiidae. (Cf. p. 451.)

1 Cf. Elliott Smith, llep. Brit. Ass. 1904.

PITHECANTHROPUS ERECTUS

515

CHAP. XVII]

(4) The situation of the line of maximum diameter of the
calvaria, i.e. more anterior than in the Simiidae, and thus agreeing
fully with the condition in the Hominidae.

(5) The angle of the nuchal plane (see Fig. 322) : in this
respect, the Javan fossil is truly intermediate between the
Simiidae and the Hominidae.

The Femur. From the calvaria we may turn to the con-
sideration of the femur (cf. Fig. 323), which,
as already said, is that of the left side. The
bone bears a striking anomaly, in the form of
an exostosis, of considerable size, springing
from the region of the linea aspera in the
upper third of the shaft. The exostosis, which
is pathological in nature, has formed the
subject of a good deal of discussion, as the
net result of which, it seems that the bearing
of this feature is absolutely nil as regards the
determination of the real nature of Pithecan-
thropus erectus. In size and in its general
features the femur is so human, that Dubois
himself admits that had it not been associated
with the calvaria, the femur would have been
regarded by him as that of a man1.

The shaft of the femur is remarkably
straight, though not absolutely so. This

feature might be thought to establish a point m favour of referring
the bone to a member of the Hominidae. But observation,
stimulated by the interest of the research, shewed (a) that the
shaft of the bone in mankind may be quite appreciably curved
(with the convexity of the curve directed forwards), without
modifying the erect attitude of the individual; and (b) that in the
(arboreal) Hylobatidae among the Simiidae, the femoral shaft may
be distinctly straighter than in the (terrestrial) Hominidae.

In the femur we must therefore recognise certain features
as simian, and according to Dubois and others, some of these
are distinctly approximate to the conditions in Hylobates, viz. :

1 In this case, the existence of Man in the Tertiary epoch (Pliocene) would be
established.

33—2

516

PITHECANTHROPUS ERECTUS

[SECT. D

(1) The straightness of the shaft.

(2) The fulness of the bone on the inner side of the shaft:
this is associated with a lack of prominence of the linea aspera.

(3) The fulness and convexity of the shaft at its lower end in
the popliteal space, so that instead of the flattened area seen in the
vast majority of human femora, there is seen a bulging, which is
excessively rare in the Hominidae ; and the resulting index of
platymeria provides the very high (numerical) value of 97.

(4) The feebleness of the inter-trochanteric line.

(5) The position of the adductor tubercle on the inner aspect
of the internal condyle at the lower end of the bone, as judged by
the “Bandradien” index1 the femur is simian rather than human.

Against the foregoing simian characters, may be set the
following human features:

(1) The absolute length, which is given as 455 mm. (with an
associated stature of 1650 to 1700 mm.).

(2) The slenderness of the shaft.

(3) The presence of a distinct linea aspera.

(4) The size of the head of the bone.

(5) The length of the femoral neck.

Finally it must not be forgotten that some of the characters in
the first list are not beyond the range of variation of undoubted
human femora.

The Teeth. The teeth
one lower premolar. Of the
former, one is from the left
side of which it is the second
tooth, while the other (Fig.
324) is a third upper right
molar2. The principal cha-
racters of these two teeth are
as follows3 :

(1) The roots are strong-

consist of two upper molars and

Fig. 324. The last upper right molar
tooth of Pithecanthropus erectus. De-
generacy is denoted by crenation and com-
parative reduction of the antero-posterior
diameter of the crown, which is markedly
inferior to the transverse diameter.

1 Cf. Bumiiller, Dos menschliche femur, p. 131.

2 Amoedo, quoted by Kiikenthal, Jahresber. tier Anatomic (1002), considered
this to be a first molar tooth.

3 Dubois, Anatomischer Anzeiger, Band xii. 1896, p. 16.

CHAP. XVI I ] PITHECANTHROPUS ERECTUS 517

ly divergent, and thus the teeth are clearly distinguished from
modern human teeth.

(2) The dimensions of the crowns exceed those of any human
races, save certain macrodont negroes of Oceania or aboriginal
natives of Australia. The figures provided by Dubois are compared
in the accompanying table with other data, some of which (for
the Gorilla and Orang-utan) are based on measurements of speci-

mens in the Cambridge Anatomy School.

Sagittal diameter

(a) Third upper molar tooth :

Transverse diameter

Pithecanthropus erectus

11-3 mm.

15-3

mm.

Australian aboriginal (Virchow)

10-5 „

15-0

Average from live Gorillas

15-6 „

16-25

,, ,, six Orang-utans

13 „

14-1

In this tooth, reduction of the sagittal diameter as compared
with the transverse diameter is marked; this is a feature which
approximates Pithecanthropus erectus to the Hominidae, and

separates it from the Simiidae.

Sagittal diameter

Transverse diameter

(b) Second left upper molar tooth :

Pithecanthropus erectus

12-0 mm.

14-0 mm.

Australian aboriginal (Virchow)

12-5 „

15-5 „

Gorilla (average of five examples)

16-2 „■

16-0 „

Orang-utan (average of six examples)

12-9 „

15-0 „

The third molar tooth will be seen in comparison to be
degenerate in point of size. This degeneration has commenced
even in Gorilla, and reaches its maximum in the Hominidae.

(3) The postero-internal inner cusp is in each of these teeth
distinctly the smallest and is therefore degenerate: in the Simiidae
the postero-external cusp is said to become reduced before the
postero-internal cusp is affected. But as a matter of fact, the
crown of the third upper molar tooth of Pithecanthropus erectus
(cf. Fig. 324), is clearly degenerate, and even the other cusps are
but vaguely marked ; there is a certain amount of crenation, which
would have probably in any case obscured the lines of distinction
of the several cusps. Keith suggests in fact that the tooth is
actually that of an Orang-utan.

(4) The roots of these molar teeth are large and very strongly
divergent. This is a simian, and not a human feature.

518

PITHECANTHROPUS ERECTUS

[SECT. D

(5) The proportion of the transverse diameter of the crown
of the second molar tooth, to the maximum transverse diameter of
the calvaria, is identical with the proportion yielded by a female
Hylobates skull measured by Dubois: this proportion is in male
Hylobatidae greater, and in the Hominidae less, than in Pithecan-
thropus erectus.

(6) I have not been able to find a description of the lower
premolar tooth, but in conversation, Dubois mentioned that in
the lack of incurvation of the inner cusp, it resembles the corre-
sponding tooth of the Hominidae.

To sum up the characters of these teeth, it will be seen that
while distinguished from human teeth by the large dimensions of
the crown and roots, and by the strong divergence of the latter, they
nevertheless differ from the teeth of any member of the Simiidae.

Having now considered the several specimens apart, it remains
to consider the outcome of their association in a single individual.
We may, by way of recapitulation, repeat that the characters
of the calvaria and teeth are on the whole intermediate between
those of the Simiidae and the Hominidae, while the balance of
evidence, as regards the femur, tends ( pace Dr Bumuller) to shew
that it is quite possibly human. From the characters of these
remains, we must picture Pithecanthropus as an animal of
considerable size (for the femur indicates a stature of about
1650 to 1700 mm.) with a corresponding body- weight of about
70 kilogms. So bulky an animal must have been largely terres-
trial in habitat, and if terrestrial, had probably assumed the erect
attitude. The great brow-ridges of the calvaria, and the large
teeth, shew that the jaws were larger than in any of the Hominidae,
and probably not very different in proportionate bulk from those
of the existing Hylobates (cf. Fig. 70). But the cranial capacity
indicates the possession of a brain weighing about 750 gm.
The question must now be asked, Does this amount of brain-
substance, taken in relation with the body-weight, provide
the correct proportion for a man, or for an ape, or for neither?
Now quite apart from the detailed consideration of brain-weight
as an index of intellectual capacity, the very high ratio of brain-
weight to body-weight is characteristic of the Hominidae (taken
en bloc).

CHAP. XVII]

PITHECANTHROPUS ERECTUS

519

From the weights of brains recorded by Max Weber and
others, Dubois has made a careful investigation into the proportion
of brain-weight to body-weight in a series of animal forms, and
the foregoing statement is one of the results of that enquiry1.
The ratio of brain-weight to body-weight may be called the
cephalisation of the particular animal. (Cf. p. 403.)

If now we start with the value of the brain-weight of Pithecan-
thropus erectus2, and calculate the corresponding body-weight on
the assumption (of Turner, Cunningham and other anatomists)
that Pithecanthropus erectus was human, we find from the data
provided by Dubois that this body- weight should be about 19
kilogms. This result must be checked by a comparison of the
value for the body-weight, inferred from the stature, the latter
value being in turn given by the femoral length. The length of
the femur shews that the body- weight was about 70 kilogms. The
great discrepancy in these results leads to the inference that
Pithecanthropus erectus was probably not human.

If next, in company with Waldeyer, Ranke, Bumiiller and
others we assume that the relations of Pithecanthropus erectus are
with the Simiidae and not with the Hominidae, we shall find (still
using the data provided by Dubois) that the appropriate body-
weight for an ape with a brain weighing 750 gms. is nearly 230
kilogms., whereas actually the femoral length of Pithecanthro-
pus erectus will not provide a greater bulk than 70 kilogms.
The discrepancy is even greater than before, and 230 kilogms. is
an enormous weight for a Primate Mammal: we therefore conclude
that the simian nature of Pithecanthropus erectus is not proven.

The final researches of Dubois, carried on from this point, shew
that not only are we caught in a dilemma as just shewn, whether
we assume that Pithecanthropus erectus is human or simian, but
also on the positive side, the comparison of brain-weight and body-
weight in Pithecanthropus erectus leads to the conclusion that the
cephalisation is but half that of the Hominidae and nearly twice
that of the Simiidae. Such a demonstration of the truly inter-

1 Cf. Dubois, Arcldv. filr Anthropologic, Band xxv : I)ic Abhiingigleeit clcs Hirnge-
wichtcH von der Korpergrosse : also Dubois, Proc. Int. Cong. Zoology, Cambridge
1898.

2 The brain-weight is estimated by means of the value of the cranial capacity.

520

PITHECANTHROPUS ERECTUS

[SECT. D

mediate position of Pithecanthropus erectus is all but complete,
for the only positions left to those who do not accept this con-
clusion, are (a) that Pithecanthropus erectus was a human
microcephalic idiot, of the type in which the amount of brain
substance is very materially reduced. In this connection it must
be repeated that the chances are very much against the preserva-
tion of the remains of such an idiot since the Pliocene period :
and secondly, that such individuals rarely survive to maturity and
are even then usually stunted in growth, whereas the Trinil fossil
was of stature rather over the average : (b) that Pithecanthropus
erectus was an anthropoid ape of a degree of cephalisation far
superior to any ape now existing. But the latter fact would of
itself remove the Trinil fossil from the Simiidae, and would place
it exactly in the intermediate position claimed for it by its dis-
coverer.

This claim must, in my opinion, be considered as justified.
As I have elsewhere stated1, I believe that in Pithecanthropus
erectus we possess the nearest likeness yet found of the human
ancestor, at a stage immediately antecedent to the definitely
human phase, and yet at the same time in advance of the
simian stage.

Family Hominidae.

XIV. Homo primigenius ( seu neanderthalensis). With
Pithecanthropus erectus, we pass the gap which separates the
Simiidae from the Hominidae. This passage is moreover effected
independently of the view adopted as to the precise morphological
status of the fossil Primate discovered by Dubois. Those remains,
as we have just seen, were found in strata referred, on geological
considerations, to the Pliocene epoch, i.e. to the later stages of the
Tertiary period.

The exact geological horizon upon which the Hominidae make
their earliest appearance is still unknown, though surmise and
speculation have long been rife upon this subject. Incidentally we
may remark that materials for the solution of the problem are
supplied, not only by the fossil remains of Man, but also by
implements, the work of human hands. Actually, it cannot be

1 Jo urn. A. and P. Vol. xxxv.

FOSSIL HOMINIDAE

521

CHAP. XYIl]

stated with confidence that the Hominidae existed even in the
latest phases of the Tertiary period, even with the extension of
evidence thus provided. For years past announcements have at
intervals been made of the discovery of human artefacts of
undoubted tertiary age : and hitherto in no case has the evidence
been sufficiently strong to ensure general recognition of the claim
advanced1. While the existence of Man in the Tertiary epoch must
remain for the moment uncertain, there can be no doubt as to the
early appearance of Man in what is known as the Diluvial period.

It is a remarkable fact that among the human crania for which
great antiquity has been claimed, much diversity of form obtains2.
This might indicate that the several varieties in question were
evolved simultaneously with the human form, or that the claims
put forward for the extreme age of the specimens are false.
These possibilities demand the very closest investigation, and it
must be remembered that the process of evolution is in some
instances very rapid. If so in this case, the co-existence of round
and long skulls at an early epoch in human evolution would be
comprehensible though perhaps not easily explicable ; as it is,
Palaeontology has not yet provided definite evidence of the pos-
session by primitive man of one tj^pe of skull to the exclusion
of others, though among the individuals of acknowledged an-
tiquity, the long-heads are in a majority.

Apart from the single characteristic of the proportions of the
brain case, several other anatomical features are found to be so
combined in certain fossil crania, as to confer upon these a dis-
tinctly lower status than that of any of the existing races (even
the aboriginal races of Australia not excepted). The individuals
thus characterised are associated in a group specifically distinct
from the modern Hominidae, to which the name Homo primigenius
or Homo neanderthalensis, has been applied. But so far as'
I can judge, four individuals only seem to be endowed with the
qualifications requisite for such independence. It must remain
a matter for discussion whether these are to be regarded as

1 Geikie, Text Book of Geoloyij, 1903, points out the difficulty that is met with
in determining the precise age of flint implements, and therefore the claim to
antiquity of the so-called “eolithic” specimens cannot be yet unreservedly accepted.

2 This fact to some extent militates against the view' expressed on p. 456 supra.

522

FOSSIL HOMINIDAE

[SECT. D

individual cases of reversion, or as examples of a species of
Hominidae now extinct. From an examination of the evidence,
I consider that the latter view is justified and shall therefore refer
to this variety as specifically distinct, under the title just
mentioned (viz. H. primigenius, sen neanderthalensis).

H. primigenius is represented by the following examples :

(a) the portions of the skeleton1 discovered in 1856 by Fuhlrott in
the valley of the Neander (near Diisseldorf) ; ( b ), the crania, with
other portions of the skeleton2, discovered in 1885 at Spy in
Belgium, by de Puydt and Lohest ; (c) the fragmentary remains of
several skeletons (from which part of one calvaria3 has so far been
reconstructed) found at Krapina in Croatia, by Kramberger.

(4) The actual remains comprise the following parts : —

(a) The skeleton from the Neanderthal, Germany. These
remains, which are now in the Antiquarian Museum at Bonn,
comprise the calvaria, the two femora, the right humerus complete,
the lower two-thirds of the left humerus, the left ulna complete,
the proximal half of the right ulna, the right radius complete, part
of the left os innominatum (ilium), part of the right scapula, the
right clavicle and some fragments of ribs.

( b ) The Spy specimens consist of portions of two skeletons,
assigned with some doubt to male and female individuals re-
spectively. Of the skulls, rather more than the calvaria remains
in each case, and fragments of the mandibles with the teeth still
in situ were also discovered.

(c) The Krapina fragments comprise remnants of about ten
skeletons. The crania are fragmentary. Many teeth were found
(the total number amounting to 115).

Such classical examples as the crania from Canstatt4 5, Egisheim6,

1 Fuhlrott, Verhand. de.r naturahist. Vereins derpreuss. Rheinlandes und Westfalem,
1857 : quoted by Schwalbe, Der Neander thalschddel, Bonner Jahrbiichcr, Heft 160,
1901. The Neanderthal skeleton has given a name to the species.

2 Fraipont et Lohest, Archives de Biologic , Tome vn.

3 Gorjanovic-Kramberger, Mitt, der Wien. anth. Ges. xxxi. Band, pp. 164 197,

xxxii. Band, pp. 189 et seq.

« Spleiss (stated by Fraipont and Lohest not to have recognised the human
nature of the specimen) in Dissertatio Historico-physica de comibus et ossibus
fossilibus Canstadiensibus, 1701.

5 Faudel, Bull. Hoc. hist. nal. de Colmar, 1867.

CHAP. XVII]

FOSSIL HOMINIDAE

523

Gibralter1 (Forbes Quarry), Hungary (Shipka)2, Galley Hill in
Kent3 Tilbury4, Engis in Belgium5; from Abbeville6, Chancelade7,
Denise8, Cro-Magnon9, and other localities in France ; and from
Brtlx in Bohemia10 with many others11, are thus excluded from
morphological association with the foregoing more lowly examples12.
Schwalbe13 has recently modified this classification, and groups the
Neanderthal, Spy, Krapina, La Naulette14, Arcy16, Malarnaud16,
Shipka, and Taubach17 remains together as those of Homo
primigenius, and distinguishes these from palaeolithic remains of
Homo sapiens, to which he refers the Egisheim, Tilbury, Denise,
Briinn18, Predmost19 and a few other fossil examples. Attention

1 Broca, Bull. Soc. d’Anth. de Paris, 2e S6rie, t. n. and iv.

2 Maska, Mitt, der Anth. Ges. in Wien, 1882, see also Virchow, Zeitsch. filr
Ethn. 1882, p. 300 ; and Schaafhausen, Vereins der preuss. Rheinl. u. Westfalens,
1883.

3 Newton, Geological Magazine ; also Klaatsch, Zeitsch. fur Ethn. 1903.

4 Owen, Discovery of a human skeleton at Tilbury, London, 1885.

5 Sehmerling, Recherches sur les ossements fossiles, 1833.

6 Turner, Rep. Brit. Ass. for the Adv. of Science, 1863.

7 Testut, Bull, de la Soc. d’Anthr. de Lyon, 1890, p. 152.

8 Aymard, Bull. Soc. Geol. de France, 2e s6rie, t. n. 1844, etc. ; Sauvage, Revue
d’Anthropologie, 1872, p. 289.

9 Reliquiae aquitanicae ; also Bull, de la Soc. d’Anth. de Paris , 2e S6rie, t. hi.
1868.

10 Fritz und Bokitanski, Mitt, der Anth. Ges. in Wien, 1872.

11 Zittel (Handbuch der Paldontologie Bd. iv. 1893) unhesitatingly rejects the
claims of a number of fossil crania : their claims to interest were largely based on
their supposed geological antiquity. Incidentally it may be remarked, that Zittel
(op. cit.) excludes from serious consideration the fossil skeleton of the Neanderthal,
on the ground that it is of comparatively recent date.

12 One of the most recent and exhaustive summaries of the literature of
this subject is provided by Klaatsch, Anatomische Hefte, Bd. xii. 1902, pp. 552
et seq.

13 Die Vorgeschichte des Menschen, 1904. Cf. also D. MacCurdy’s review in the
American Anthropologist, Vol. vi. No. 2, April — June, 1904.

14 Broca, Congres internat. d’Anthr. et d'Arch. prehist. 1867 ; Compte rendu,
p. 398. Also Fraipont, quoted by Walkhoff, Selenka’s Studien, Heft ix.

15 Be Quatrefages et Hamy, Crania Ethnica, p. 25.

16 Filhol, quoted by de Mortillet, Le Prehistorique, p. 266.

17 Nehring , Zeitsch. f. Ethn. 1895, Band 27, p. 573 : also Naturioiss. Wochenschr.
1895, pp. 371 and 522.

13 Makowsky, Mitt, der Anthr. Ges. in Wien, Bd. xxii. 1892, p. 73.

19 Maska, Congres internat. d’Anthr. et d'Arch. prehist. xii0. Session, 1900.
Compte rendu, Paris, 1902, p. 130.

524

FOSSIL HOMINIDAE

[SECT. D

will be here confined to the Neanderthal, Spy, and Krapina
skeletons, since these present undoubted featui’es of inferiority.

I. The crania, (a) The Neanderthal skull. The morpho-
logical characters of the Neanderthal skeleton have recently been
studied by a master of anatomical knowledge and technique1, to
whose work acknowledgment must be made by all who are
interested in the subject.

Fig. 325. The Neanderthal cranium, seen from above : the general features
resemble those of the crania from Spy. (Cf. Figs. 329 and 330.)

(1) The length and breadth of the Neanderthal calvaria (for
such it is, cf. Figs. 325, 326, 327) are quite comparable to those

1 Schwalbe, Der Neanderthalschadel, Bonner Jahrbilclier, Heft 106 : v. also
Schwalbe, Die Vorgescliiclite dee Mensclien , 1904.

CHAP. XVII]

FOSSIL HOMINIDAE

525

of recent human crania (viz. 199 mm. and 147 mm. respectively).
The cephalic or breadth index thus provided is 73'9. In general

Fig. 326. The Neanderthal cranium, seen from the left side: the prominent
brow-ridges and the flattened cranial are resemble the corresponding features in the
Spy crania, (v. especially Fig. 329, and also 332.)

form, the calvaria is elongated ; the sutures have been largely
obliterated by synostosis ; and the most striking feature is the
massive character of the brow-ridges recalling those of the calvaria
of Pithecanthropus erectus : the prominence of the ridges is
enhanced by the narrowness of the frontal bone immediately
behind them (Fig. 325). Among recent crania, those of the ab-
original natives of Tasmania and Australia (cf. Fig. 284, Chapter
xvi.) most nearly reproduce this condition.

(2) The median sagittal curve of the calvaria next claims
attention. (Cf. Fig. 327.) While in respect of length and breadth,
the Neanderthal calvaria falls within the range of variation of
recent human crania, it is quite otherwise as regards the height of
the cranial arc. The latter falls far short of the corresponding
curve in the crania of modern Hominidae, of whatever race. The
character is measured by determining the greatest height to which
the longitudinal arc rises above the line of maximum cranial length ;
this height is shewn by the perpendicular line in Fig. 327, and
from the comparison of the perpendicular and horizontal lines, an

FOSSIL HOMINIDAE

526

[sect, d

index of height (the Calvarial-height index, or Calotten-hohe index
of German writers) has been calculated.

Fig. 327. Tracing (after Schwalbe) of the outline of the Neanderthal skull : to
demonstrate by means of the angular measurement (0) the flattening of the cranial
arc.

In respect of this low flattened cranial vault, the Neanderthal
calvaria while differing from the corresponding portion of all recent
crania, is found to be closely imitated by the crania from Spy1, less
closely by the fragmentary calvaria from Krapina2. (Cf. Figs. 329
and 332.) Indeed the association of these fossil remains in
one species, is based largely on the community of this character.
The height of the curve represents in the Neanderthal calvaria
40-4 °/0 of the maximum calvarial (i.e. cranial) length : and the
corresponding values for other specimens will be subsequently
appended.

(3) The prominence of the brow ridges naturally contributes
to increase the flatness in appearance of the cranial vault. This
feature is indicated in the excessive length of the “pars glabellaris”
of the frontal bone, comprised between the nasion and the most
indented portion of the frontal bone. The same features of
flattened arc and prominent brow-ridges are factors which deter-
mine the value of a bregmatic angle ( 6 , Fig. 327), and in respect
of these two characters the Neanderthal calvaria while associated
with those of Spy and Krapina, is clearly distinguishable from all
recent human cania.

The post-orbital narrowing of the skull when compared with
the sudden widening which replaces it in the parietal region,

1 Schwalbe, Der Neanderthalschiidel, p. 30.

2 Kramberger, Mitt, der Anth. Ges. in Wien. Band 32, p. 202.

CHAP. XVll]

FOSSIL HOMINIDAE

527

provides another criterion of distinction, and the comparison has
been expressed in the form of a fronto-parietal index.

(4) A few other anatomical points in the comformation of the
Neanderthal calvaria must next be appended. The frontal sinuses
are bounded by much thickened walls. The parietal bone is
distinguished by the very remarkable superiority in length of the
temporal margin, over the coronal and other margins : this
distinctly simian character is related to, and indirectly deter-
mines the small degree of curvature of the cranial vault1.

The uppermost portion of the occipital squama bulges in the
suggestive manner to which reference was made in describing the
calvaria of Pithecanthropus erectus. This feature may be indica-
tive of the former presence of a well-developed sulcus lunatus in
the cerebral hemispheres2. This would be a simian feature.

The position of the torcular herophili corresponds so nearly
with the external occipital protuberance that no simian relation
can thence be claimed (in the Simiidae the torcular is distinctly
nearer the foramen magnum than in the Hominidae) : at the same
time, the view that the Neanderthal skull is that of a micro-
cephalic idiot is hereby refuted, for in the microcephalic skull, the
torcular tends to assume in position much nearer the lambda than
in the normal human skull. The fact that the capacity (estimated
in the most careful manner) is represented as 1230 c.c. finally
disposes of the last-mentioned suggestion, although this value
assigns to the Neanderthal cranium a position among the lowest of
the Hominidae. It is important to notice that the capacity is also
relatively very small, when the comparatively large dimensions in
length and breadth (of the cranium) are considered.

It has been pointed out that modern crania 200 mm. long and
145 mm. wide would have a capacity of about 1600 c.c., whereas
the Neanderthal skull, 199 mm. long and 147 mm. wide, has
a capacity of 1230 c.c. only. The variable factor is evidently the
cranial height, which, as we have already seen, is extraordinarily
small in the fossil specimen.

(b) The Spy crania. (Figs. 328, 329, 330.)

1 The ultimate cause of the lack of curvature of the vault will be found in the
growth of the brain.

2 Cf. Elliott Smith, Rep. Brit. Ass. 1904. The features of the endocranial cast
(cf. p. 451) support this inference.

528

FOSSIL HOMINIDAE

[SECT. D

Turning from the Neanderthal remains to those of Spy, we
may note that in several of the morphological features enumerated
and reviewed above, the two are in close agreement. (1) Of the
two crania from Spy, No. I. is however more distinctly neander-
tlialoid than No. II. Both are elongated flattened crania with
massive brow-ridges. The outline of the squamous bone is. not
boldly curved as in recent human crania, but flattened as in the
Simiidae. The projection of the occipital region indicates great
development of the nuchal musculature, and also possibly indicates
the former presence in the brain of a well-marked sulcus lunatus1.
The tympanic bone is broad and is scored (as in the Gorilla)
with distinct striate lines. Another simian feature is the extent
of the glenoid fossa.

Fig. 328. One of the crania (No. 1) from Spy, seen from above. The cranium
is elongated and post-orbital narrowing is marked.

1 Cf. Elliott Smith, Rep. Brit. Jss. 1904.

CHAP. XVII]

FOSSIL HOMINIDAE

529

(2) Part of the mandible of No. I. has been preserved, and in
morphological conformation this fragment fully bears out the
indications given by the other parts of the skull. In particular,

Fig. 329. Lateral view of the Spy cranium (No. 1). The prominence of the
brow-ridges is very distinct.

the mental portion of the mandible is not prominent as in most
recent Hominidae, but rather retreating. This feature is some-
times observed in the mandibles of aborigines of Australia, and is
particularly well marked in the mandible of No. I. of the four
skeletons of Australian aborigines preserved in the Cambridge
Collection.

Much stress has been laid upon the conformation of the genial
tubercles, and Huxley (rather strangely) protested against the
relevancy of such researches as were directed to this feature.
Quite recently this subject has been approached from a new point
of view by Walkhoff who has investigated the disposition of the
cancelli as revealed by the Rontgen rays. The simian mandibular

1 Selenka’s Studien, Heft ix. ; cf. also the review by Klaatsch, Anat. Hefte 1902,
pp. 622, 623.

D. M.

530

FOSSIL HOMINIDAE

[SECT. D

symphysis is largely cancellous, without any very marked trabeculae;
in recent Hominidae, the trabeculae are so closely aggregated at the
symphysis as to give rise to a dark triangular patch when the jaw
is examined : the Naulette1 mandible is most distinctly simian in
respect of the small extent of the dark patch, and the Krapina and

Fig. 330. The Spy cranium (No. 2) seen from above. Its characters, though
less marked, resemble those of cranium No. 1. (Cf. Fig. 328.)

Predmost mandibles provide intermediate stages between the
former and those of recent Hominidae. It is impossible here to
discuss fully the bearing of these observations on the views held as
to the speech of Homo primigenius, but the subject has been

1 Cf. reference, p. 523.

CHAP. XVII]

FOSSIL HOMINIDAE

531

discussed. Inasmuch however as speech is determined by the
possession of a brain of a certain degree of complexity, as well as
by that of the appropriate mandible, the problem will be at once
recognised as very abstruse.

(3) The canine teeth are not so superior in size to the
adjacent teeth as to provide a more simian appearance, or evidence
of more lowly affinities, than those of recent Hominidae. The
dental roots are long1, and prominent on their labial surfaces. The
crowns of the lower molar teeth provide distinct evidence of simian
affinities : for in the mandible of the skull No. I., the molar crowns
increase in dimensions from before backwards : herein they agree
with the corresponding teeth of the Simiidae, while differing from
those of recent Hominidae (Topinard).

But in actual dimensions these teeth are smaller than the
(upper) molar teeth of Pithecanthropus erectus, and fall far short
of those of Gorilla. In this connection, a word of warning must
be added as regards statements made on this subject without clear
specification of the molars (i.e. whether of the upper or lower
series) in question. The foregoing remarks refer exclusively to
the lower molar teeth.

As a complete series, the lower teeth of the Spy crania are
characterised, (1) by their large size2 (which surpasses that of modern
white Hominidae, (2) by projection forwards of the incisor teeth,
and (3) by the tendency to progressive increase backwards in size.

From fragments obtained in the Krapina deposit it has been
found possible to reconstruct part of a calvaria, though it is
admittedly uncertain whether all the fragments originally formed
part of the same skull or not3. The principal results of the
investigation are summed up in the following notes.

The proportions of the skull (Fig. 331) shew that it was very
distinctly brachycephalic, with an index (cephalic) of 85’5. Herein
a marked difference from the Neanderthal and Spy No. 1 crania

1 The length of the dental roots is a simian feature, as has been indicated by
Tomes (Dental Anatomy), and Walkhoff (op. cit. v. p. 529 supra).

2 Fraipont et Lohest, Archives de Biologic, Tome vn. p. C43.

3 Kramberger, Mitt, der Anth. Ges. in Wien, Band 32, p. 202.

34—2

FOSSIL HOMINIDAE

[SECT. D

5 32

Fig. 331. The Krapina skull, in norma verticalis (after Kramberger).

Fig. 332. Tracing of the (reconstructed) Krapina skull, in norma lateralis (after
Kramberger).

CHAP. XV II]

FOSSIL HOMINIDAE

533

obtains, while the Krapina calvaria is more closely resembled by
the Spy skull No. 2.

The brow-ridges (Fig. 332), like those of the Neanderthal and
Spy crania, are massive, and indeed in this respect surpass the
examples just mentioned, and even the calvaria of Pithecanthropus
erectus is furnished with less bulky prominences in the corre-
sponding situation. The frontal bone rises rather abruptly, so that
the flatness of the sagittal arc, so marked in the Neanderthal
skull, is in the present instance vestigial only : there is a median
frontal keel closely resembling that of the calvaria of Pithecan-
thropus erectus. Not only do the Krapina and Neanderthal Spy
crania resemble one another in respect of the brow-ridges, but
resemblances also obtain (a) in the relative shortness of the margo
lambdoideus of the parietal bone1, but also (b) in the character of
post-orbital compression, as denoted by the fronto-parietal index,
and (c) in the conformation of the occipital bone, i.e. in the
possession of a massive transverse torus.

The mastoid processes are but feebly developed, while there is
distinct thickening of the tympanic bone.

Some of the chief dimensions of the Krapina calvaria and a
few of the indices have been already mentioned. We may here
note that the estimated length (from glabella to inion) is
197‘5 mm. = the maximum breadth being estimated at 169 mm.

The fragmentary mandibles found with the cranial fragments
yield evidence of the prognathism of the face and shew that there
is close agreement between the Krapina men and those represented
by the mandibles found at Shipka, Predmost and La Naulette2.

As has been mentioned also, no less than 115 teeth were found
with the cranial fragments. The adult (permanent) molar teeth
are distinguished by the luxuriance of crenation on their crowns,
a feature which allies these teeth to those of the Orang-utan, and
in a smaller degree to the Chimpanzee, though not to the Gibbon
or Gorilla. The dimensions of the molar crowns are distinctly in
excess of the corresponding dimensions in modern European teeth,

1 See Schwalbe, Der Neanderthal Schadel, review by W.L.H.D. in Man, 1902,
No. 129.

2 Walkhoff, quoted by Krarnberger, Mitt., Bd. 32, p. 214.

534

FOSSIL HOMINIDAE

[SECT. D

but fall short of those of Pithecanthropus erectus, and of some
aboriginals of Australia.

II. Skeletal parts other than the skull.

(a) The Neanderthal skeleton.

While recent research has disposed of the view that suggested
a pathological explanation of the extraordinary cranial features of
the Neanderthal man, it is rather striking that research has
brought to light (in the bones of the upper limb and in the left
arm particularly) evidence of disease, though this has not produced
any effects that could be mistaken for specific morphological
characters. Schwalbe thus finds that the left elbow-joint had
been dislocated, probably in the early youth of the individual,
and the comparatively stunted growth of the left humerus and
ulna finds an explanation herein. The characters of the limb
bones have been recently studied by Klaatsch1, with the following
results.

1. The scapula presents few distinctive features. Retroversion
of the neck of the glenoid cavity is very marked however : hereby
the Neanderthal skeleton approaches that of the Orang-utan (but
not those of the Gorilla or Chimpanzee) while diverging from the
modern human type.

2. The clavicle is slender : thus it contrasts with other parts
of the skeleton, which, as a whole, is massive. Slenderness is not
however a simian feature.

3. The radius is very remarkable for the outward curvature
of the shaft. This is a feature which distinguishes the Neander-
thal skeleton from those of the modern Hominidae, and while it is
admittedly a simian feature, yet it is shared by many of the lower
Primates and even Eutherian Mammals with the Simiidae. The
interosseous space is correspondingly wider than in recent Homi-
nidae. (Cf. p. 311.)

Jh The olecranon and coronoid processes of the ulna are
unusually massive2.

1 Anat. Hefte, 1900 and 1902.

2 See Fischer, Archiv fur Anthropologic , 1903.

CHAP. XVII]

FOSSIL HOMINIDAE

535

5. The humerus : this bone is relatively short and accordingly
perfectly human. In the proportions of the caput humeri a
simian trait is found. But the olecranon fossa is imperforate.
The angle of torsion is estimated at 35° x. In Veddahs this
angle measures 30°, but only 9° in modern Europeans.

6. The hand is to all appearance perfectly human.

7. The pelvis provides no distinct evidence of morphological
inferiority.

8. The femur (cf. the Spy femur, Fig. 333) is very stout,
massive and distinctly curved : the articular ends are (relatively)
of large size. In these characters, the bone contrasts strongly
with the femur of Pithecanthropus erectus. The angle of femoral
neck and shaft is towards the lower limit of the range of variation in
modern human femora ( v . Chapter XIII.). As regards the proportion
of the transverse diameters of the articular ends of the bone to the
total length, an association must be recognised with the femora of
the Mongoloid races (e.g. the Japanese), not with those of Australian
aborigines. The shaft is not platymeric, and in other characters
of the shaft the bone diverges in type from that prevalent among
the Australian aborigines, while it approaches that of the Mongo-
loid races. The deep patellar groove (fossa supra-patellaris) is a
remarkable feature, of which the significance is not quite clear1 2.
The sudden transition in transverse diameter from the shaft to the
articular end has been particularly described by Klaatsch3.

(b) The Spy skeletons4.

(1) The clavicle is similar to that of the Neanderthal
skeleton.

(2) The radius and ulna are bowed, so as to leave (as in the
Neanderthal skeleton) a broader interosseous space. This is
a simian feature.

1 Klaatsch, Jahresber. filr Anat. und Entiv. vii. 1902, xii. pp. 162, 106, 606; Frai-
pont, Revue d'Anthr.

2 Klaatsch ( Zeitsch . fur Eth. 1903, Heft 6.) notes the presence of this fossa in
femora of aboriginal Tasmanians in the Hunterian Museum in London.

3 Jahresber. fiir Anat. und Entw. vii. 1902, xii. 162, 166, 606 : Anatomische Iiefte,
1900, p. 651.

4 Cf. Fraipont and Lohest, Archives dc Biologic, tome vii. p. 651.

536

FOSSIL HOMINIDAE

[SECT. D

(3) The humeri are stout and heavy : the olecranon fossa is
cribriform, but no definite perforation exists.

(4) The characters of the femora
(Fig. 333) are practically identical with
those of the Neanderthal femur. In
section the shaft is not flattened
(platymeric), nor is the linea aspera
unduly prominent. The third tro-
chanter is not developed, but a repre-
sentative of the depression known as
fossa hypotrochanterica (which is fre-
quent in fossil human femora) has been
recognised. On the condyles the arti-
cular surface is prolonged far backwards
and upwards as in certain primitive
Asiatics1.

(5) The tibia is extraordinarily
short, stout and strong but not platycne-
mic : the head is retroverted. Klaatsch
detects in this tibia infantile and
“ Mongoloid,” but not “ Australoid ”
features.

Fig. 333. Femur (A) of the
Spy skeleton No. 1, compared
with (B) a recent human femur
(after Fraipont, op. cit. v. p. 535
supra). These femora should
be compared with those of Pi-
thecanthropus erectus (Fig.323)
and of an Orang-utan (Fig. 302).

(6) The fibula. The chief point

of interest lies in the fact that the long axis of the fibula seems
to have crossed that of the tibia, instead of remaining parallel to
it as in the Mongoloid races. Herein there is agreement between
the Spy skeletons and those of recent white Hominidae. But it
must be remarked that the evidence for the statement is based on
the characters of only a fragment of the fibula.

(7) For the os calcis, Leboucq (quoted by Klaatsch) records
an index which shews that the bone is either less elongated, or
broader than modern calcanea. The former condition is simian.

(8) The tarsal bones of the Spy skeleton No. 2 suggest that
the foot was large, but not notably different from those of modern
Hominidae.

1 Negritoes and Punjabis; cf. Charles, J. A. and P. Vol. xxvm. p. 1.

CHAP. XVII]

FOSSIL HOMINIDAE

537

As to the limb bones of the Krapina skeletons little or no
information is as yet available. Kramberger1 figures a patella,
and part of an immature scapula: Klaatsch2 notes that a navicular
bone has been found, but this does not yet appear to have been
minutely studied. A child’s clavicle is also stated to have been
preserved intact.

General conclusions from the foregoing descriptions.

A review of the characters of the fossil remains from the
Neanderthal, from Spy, and Krapina leads to the conclusion that
the individuals thus preserved possessed a combination of morpho-
logical features which places them in a distinctly lowlier position
than the modern Hominidae. If one examines the history of this
subject one finds that just as the announcement (in 1894) of the
discovery of Pithecanthropus erectus was the occasion of stormy
debates as to its exact nature, so at an earlier date (1857) the
precise status of the Neanderthal fossil skeleton furnished material
for discussions no less protracted nor, it may be added, less heated.
And just as contemporaneous opinions in 1894 on the question of
the nature of Pithecanthropus erectus could be ranged in three
district camps (cf. p. 511), so also anatomists and anthropologists
were divided in opinion forty years previously, upon the question
of the Neanderthal man. An interesting comparison with the table
drawn up in the case of Pithecanthropus erectus to shew the
different categories into which the several observers are divisible,
is provided by Schwalbe3 and is here appended.

I. The Neanderthal skull is not typical of a special variety,
but is a sporadic case, which departs unusually far from the
normal.

(а) The modification in form is the result of premature

cranial synostosis. Barnard Davis.

(б) The individual was idiotic. Blake, C. Vogt and

Pruner-Bey (at one epoch), v. Holder, Zittel.

1 Mitt. loc. cit. Taf. 3 and 4.

2 Anatomisclie Hefte, 1902.

3 Der Neanderthal Schddel, pp. 56-57.

538 FOSSIL HOMINIDAE [SECT. D

II. The Neanderthal skull is within the ordinary range of
variation of human crania of modern times.

(a) The recent skull of a Cossack. Mayer.

( b ) The skull of a member of an ancient but historic

race :

(i) Ancient Kelt or Teuton. Prunei'-Bey (at one epoch).

(ii; Ancient Dutch or Frisian: a Batavian. Wagner.

„ „ „ a Frisian. Virchow (1876).

which is however linked by “ neanderthaloid ”
forms of skull to the most primitive of existing
races.

(a) Similar to aborigines of Australia. Huxley, Lyell,

C. A^ogt (at one epoch), De Quatrefages, Hamy.

(b) Representative of a particular race, viz. that of

Cannstalt, Do Quatrefages, Hamy.

from modern Hominidae. Schaafhausen, Fraipont,

Lohest.

(ii) A race distinguished from modern white races
just as the modern negro is from the modern
white man; the Neanderthal race. De
Mortillet.

III. The Neanderthal skull represents a form which is
distinct in species and perhaps even in genus from all existing
Hominidae. King, Cope, Schwalbe.

We may now give some more detailed evidence as to the
agreement in general conformation of the several examples
previously described apart. I. First, one may consider the actual
length and breadth of the specimens, as shewn in the following
table :

CHAP. XVll]

FOSSIL HOMINIDAE

539

Length Breadth

(1)

Neanderthal.

199

147.

(2)

Spy, No. I.

200

140.

(3)

Spy, No. II.

199

150.

(4)

Krapina.

197-51

1691.

II. Secondly, the fronto-parietal index, expressive of the
relation of the minimal post-frontal, to the maximum parietal
breadth, provides the following figures.

(1)

Neanderthal

731.

(2)

Spy, No. I.

712.

(3)

Spy, No. II

7T2.

(4)

Krapina

64-7 !

(5)

Average value of the preceding . . .

70.

(6)

Average of lowly Hominidae2

77.

(7)

Pithecanthropus erectus ...

65-4.

III. In the third place, the flattening of the cranial arc,
as expressed in the calvarial-height index, yields material for
comparison as follows.

Calvarial-height index (the height of the calvaria as a per-
centage of its length).

(1) Neanderthal ... ... ... ... ... 40-4.

(2) Spy, No. I. ... ... ... ... ... 409.

(3) Spy, No. II 44 3.

(4) Krapina (the mean of two determinations3) ... 461.

(5) Average value (from the four preceding indices) 42-9.

(6) Lowest figure provided by a recent human skull 52

(7) Highest figure provided by an anthropoid ape

(Simiidae) 37'7.

(8) Pithecanthropus erectus ... ... ... 34-3.

The gap separating the fossil from the recent Hominidae is
thus represented by a difference amounting to nearly 20 °/0 .

1 Estimated, not directly measured.

2 Aborigines of Australia. This index is not however an absolutely safe means
of differentiating the Simiidae from the Hominidae (Schwalbe). The Krapina
specimen provides an extraordinarily low figure for this index.

3 From two reconstructions of the calvaria. There is some ambiguity in
Kramberger’s table in p. 203 of his memoir cited on p. 531.

540

FOSSIL HOMIN1DAE

[SECT. D

IV. Fourthly, the prominence of the supra-orbital ridges is
denoted by means of an index expressive of the relation of the
glabellar to the cerebral part of the frontal arc1. The figures are :

(1) Neanderthal ... ... ... ... ... ... 44-2.

(2) Spy, No. 1 41-5.

(3) Spy, No. II. ... ... ... ... not determinable.

(4) Krapina not determinable, but probably greater than 45.

(5) Recent Hominidae (range) ... ... ... 21 to 32.

(6) Simiidae 30 to 40.

(7) Cercopithecidae ... ... ... ... 50 to 60.

V. Fifthly, the bregmatic angle is expi’essive of the degree of
curvature of the cranial arc, as well as of the prominence of the
brow-ridges. This angle has provided the following data:

(1) Neanderthal

(2) Spy, No. I.

(3) Spy, No. II

(4) Krapina

(5) Recent Hominidae (range of variation) ...

44°.

45°.

50° 30'.
51 3 30'.
53° — 66°.

The preceding list might be very considerably extended, but is
adequate to demonstrate the agreement in conformation upon
which so much stress has been laid.

As a final summary of cranial characters, the following classifi-
cation will be found both instructive and suggestive.

(a) In respect of certain characters, Homo primigenius falls
within the range of variation recognised in l’ecent human crania.
Such characters are,

(1) The cephalic index.

(2) The relation between the minimal frontal and maximal
parietal breadth (expressed by the fronto-parietal index). The
Krapina skull forms an exception to this statement, for in this
character it falls below Pithecanthropus erectus.

(3) The breadth of the inter-orbital space.

1 Cf. Schwalbe, Der Neanderthal Schddel, p. 29.

CHAP. XVII]

FOSSIL HOMINIDAE

541

(/3) Certain characters, such as the following, are distinctly
simian, for they do not occur in recent human crania, though
found in the crania of Homo primigenius and those of apes
(Simiidae) :

(1) The excessive length of the pars glabellaris of the
frontal bone.

(2) The very large proportion of the frontal component of
the median sagittal cranial arc.

(7) Finally, there are characters which place Homo primi-
genius in a position intermediate between recent Hominidae and
the Simiidae. Such characters are :

(1) The flattened curve of the cranial vault. (Cf. Fig. 327.)

(2) The low numerical value of the bregmatic angle. (Cf.
Fig. 327.)

(3) The small vertical height of the bregma above the
glabello-occipital line. (Cf. Fig. 327.)

(4) The low numerical value of the frontal angle.

The evidence derived from the limb bones has already been
surveyed. It should be added that Pearson1 estimates the stature
of the Neanderthal man at 1629 mm., and that of the male
skeleton from Spy at about 1600 mm., figures representative
of stature below the average for Western Europe at the present
day.

For the differences between Homo primigenius and recent
Hominidae a specific value can therefore be justly claimed.
Klaatsch2 insists on this point, but at the same time records his
conviction that the differences do not point to Pithecanthropus
erectus and the Simiidae as the precursors of the Hominidae.
Klaatsch postulates the existence of an ancestral series, parallel
to that which has culminated (according to Klaatsch) in the
Simiidae, and through which the Hominidae are connected with
an ancestor which they share in common with the Simiidae.

It cannot be said that this opinion is unjustifiable, much less
can it be disproved. At the present time one has to select that
view which appears on the show of evidence to be the most
probable. With such considerations in mind, it must be urged

1 Phil. Trans. 192 A, p. 205.

2 Jahresberichte filr Anat. u. Entw. vii. 1902, xii.

542

FOSSIL HOMINIDAE

[SECT. D

that Klaatsch has still to produce evidence, in the form of
specimens (pithecoid, and yet not referable to the Simiidae) which
have figured in the line of descent between the hypothetical
ancestor and the Hominidae. Such evidence may never be forth-
coming: it seems as if only palaeontological discovery were capable
of providing it. But I feel assured that should the missing links
come to light, and be subjected to a morphological analysis, some
at least would present many features (such as those of the cerebrum)
which would compel the observer to group them with the Simiidae
rather than with any other known family of the Primates. They
would, moreover, be further removed from the Hominidae than is
Pithecanthropus erectus.

Additional evidence may at a later date be derived from the
study of casts of the cndocranial cavities of the preceding calvarial
fragments. In connection with this subject, reference must again
be made to the peculiar conformation of the left occipital region
of the Neanderthal brain1, as judged by the endocranial cast;
and also to the occasional discovery of semi-fossilised brains in
very ancient crania. The best-known instances are provided by
very ancient human remains in Egypt ; allusion has already2 (cf.
Chapter xv.) been made to Elliott Smith’s researches on such
cerebral fragments as have been thus preserved. Professor Montelius
informs me that the brain is sometimes partially preserved in
crania exhumed from the Scandinavian peat-deposits ; and a
similar instance is recorded in the case of a cranium from one of
the famous mounds in Ohio8.

1 p. 451.

2 p. 451.

3 p. 451.

CHAPTER XVIII.

CONCLUSION.

With the foregoing review of human palaeontology the survey
proposed in the introductory Chapter (p. 11) of this volume is
brought to a conclusion. It is appropriate to summarise the
general inferences which result from the balance of evidence thus
set forth.

I. From that evidence it appears that the close association
of the Hominidae with the higher Primates (Simiidae) has been
continuously confirmed by the researches of the last forty years.
But while it is shewn that the Hominidae have in their evolution
passed through a stage which is better reproduced by the Simiidae,
than by any other of the Primates, it is practically certain that
the modern Simiidae did not themselves figure in the ancestry of
Man, and that they are themselves specialised in a high degree,
more specialised in many ways than the Hominidae (cf. Chapter v.
p. 120), and more specialised than their own ancestors. As
Klaatsch puts it1, the ancestors of the modern Simiidae were more
anthropoid than the actual Simiidae, just as the ancestor of the
Hominidae was more pithecoid than modern Man. And the
balance of evidence indicates that the line of human ancestry
would, were the material still available, be traceable down to the
lowest Primates (Lemuroidea2) and even to the lowest Mammals3.

1 Bericht der xxxii. Verxamm. der Deutechen. Antlir. Ges. in Metz, 1901 ; Arch,
fiir Anth., Band. 27, ss. 102 et seq. Also Bericht dc. Dortmund, 1902. Arch, fur
Anthr. Band. 28, s. 136.

2 It must not be forgotten that the Lemuroidea and Anthropoidea are distin-
guished very clearly by the characters of the blood-serum, as demonstrated so ably
by Nuttall, Friedenthal and others. But the modern Lemuroidea are of course
specialised, as compared with the ancestral stock whence they and the Hominidae
derive their common origin.

3 Cf. Cope, op. cit., vide Chapter vi. p. 153.

544

CONCLUSION

Moreover, it is undeniable that the Hominidae have retained in
hand and foot some features of an early ancestor, from which
they have departed less in type than have the (modern) Cercopithe-
cidae and Siiniidae. But detailed information on these points is
still lacking.

II. In the second place it is evident that the Hominidae, if
retraceable to an ancestral stage which is common to them and
the Lemuroidea, have most probably inhabited the earth since the
early Tertiary epoch. There seems no means of escaping this
conclusion, except by remembering the possibility that in the
period mentioned, the representative of the modern Hominidae
might be so different from Man, and so like the lemuroid
ancestor, that it would be difficult to recognise its true nature.
There comes a point therefore at which we should fail to
recognise the human ancestor, and this point will, I believe, be
found to fall within the later Tertiary period, and probably in its
Pliocene division.

III. Thirdly, when we examine the evidence bearing on the
comparative morphology of the human races, we shall find that
we are confronted with another set of problems similar to the
preceding. While there is little doubt that simian features are
not all concentrated in any single race (this was pointed out
by Turner some years ago1), yet there can be no doubt that the
aborigines of Australia and Tasmania have (up to the present)
furnished the examples of the greatest concentration of ape-like
characters. But we must not therefore conclude that these
aborigines present us with a fac-simile of a human ancestor ; for
these very aborigines are themselves remarkably specialised, in
adaptation to their surroundings. Our conclusion will be more
correct if we make allowance for this specialisation, and await the
advent of details regarding the structure of the Asiatic Negritoes
and several African races (and particularly some of the pygmy
types). To all alike the ancestral human characters have in
greater or lesser degrees been transmitted, and we must gather up
threads of evidence from all, and not from one only in the attempt
to arrive at a reliable reconstruction of the parent form.

1 Cliall. Rep. xlvii.

CHAP. XVIIl]

CONCLUSION

545

#From the preceding paragraph it will be correctly inferred
that I am not prepared to accept Schoetensack’s view1 that the
Hominidae have been evolved in the Australian continent. Africa
and southern Asia present at least equal claims to have been the
scene of that phenomenon ; and though a decision between the two
appears to me in favour of the latter continent (Asia), there is
much to be urged on both sides. The New World seems, from
the evidence at present available, to possess no such claim.

IV. The factors which have determined the evolution of the
various modern human types may be summed up under the com-
prehensive, but somewhat vague term, “ environment.” Of these
influences one of the most potent is geographical situation, with
its attendant advantageous or disadvantageous relations to tempera-
ture and food supply, and with indirect effects on habits and
temperament. By the latter, the action of such secondary factors
as sexual, physiological, and other modes of selection, must be
profoundly influenced.

By such conditions the path of morphological evolution has
been determined in the past, and in the future it will be modified
by similar influences, masked though they may be in the more
civilised of the Hominidae2. The latter hold an absolutely unique
position among the Mammalia (and for that matter, in the whole
biological world) ; on them, specialisation of the cerebrum has con-
ferred an altogether exceptional development of self-consciousness.
When we reflect that with this are combined ability to formulate
and communicate, and power to record ideas, the immense ad-
vantages of such specialisation become apparent. Thus it is that
the highly-civilised races have it so largely in their own hands,
not merely to adopt ordinary means of adaptation which they
share with other races and animals, but to employ methods of self-
preservation hitherto unattainable by any organism.

The future evolution of the Hominidae seems likely to occur
in populations of mixed origin ; for the least mixed races (aboriginal
Australian, Negrito, Bush native and Eskimo) are without ex-
ception diminishing in number and are doomed to early extinction.

1 Z.filr Ethn. Band 33.

2 This statement is not in full accord with Huxley’s view, as expressed in the
Romanes Lecture, 1893, pp. 32 et eeq.

D. M.

546

CONCLUSION

Morphologically, it appears that specialisation of the cerebrum
(particularly of the neo-pallium) is still an indispensable condition
of human survival ; but it is hard to see how subsequent advances
in gross anatomy are to be effected, except by increasing still
further the complexity of the neopallial folds. It seems therefore
probable that the future changes will affect the minute structure
of the neopallial cortex.

Concurrently, diminution in the maxillary and mandibular
skeleton and apparatus may be carried further than at present,
but this brings out a consideration of great importance. It is to
be remembered that for the proper maintenance of each system,
adequate nutrition is a prime necessity; and maxillary reduction
will be limited by this factor. So also, the future modification of
the cerebrum will be largely dependent on its blood-supply, which
in turn is related to the quality of the cardiac muscle and various
physiological factors.

From these considerations it is evident that due and proper
reaction between the vascular, nervous, and other systems is a
condition of survival. Such physiological equilibrium can only
be obtained by the proper exercise of its functions by each
system of tissues involved. We are thus led to the conclusion that
cerebral specialisation, the prime factor in the future, as it has been
in the past evolution of the Hominidae, is ultimately dependent
on what may, in the widest sense, be termed hygienic conditions.

By the exercise or neglect of these the future evolution of
the Hominidae will be determined : failure to comply with such
demands will eventually lead to extinction.

GENERAL INDEX.

Aard-vark ; see Earth-pig
Abdominal viscera ; of Lemur, 57
Accessory ribs and rib-bearing vertebrae,
222

Aehsel-bogen (a muscle), 220, 381
Acromegaly, 255
Adapis, 500, 501
Aethalium septicum, 456
Affenspalte; see Sulcus lunatus
African negroes; cranial indices, 264,
266, 287 ; inter-membral index, 331 ;
radio-humeral index, 335 ; tibio-
femoral index, 337 ; sebaceous glands,
360 ; steatopygia, 48, 360, 483 ; mam-
mary glands, 360 ; Lobengulism, 360 ;
eye-colour, 361, 362; hyper-metropia,
362; ears, 365; cerebrum, 433-437;
cranial type, 461, 464, 466, 468, 471-
473; stature, 472; skeleton, 472; skin,
473; hair, 360, 473; eyes, 473; mus-
cular system, 473; brain, 473
African Pygnues; intermembral index,
331 ; radio-humeral index, 335 ; tibio-
femoral index, 337 ; humero-femoral
index, 340; hair, 355, 356, 360
Ainu; sacrum, 290; pelvis, 300; hair,
355

Akanthion, 229, 230
Akrocephalic crania; see Thyrsocephalic
crania

Alimentary system; in Cercopithecus,
68; in Gorilla, 96; in Nasalis monkey,
68, 69

Allantois, 193, 199, 208, 209, 211,
212

Altitudinal index ; see Height index
Alveolar index, 259, 260, 261, 263,
264

Alveolocondylar plane, 230
American Indian ; sacrum, 290
American races; hair, 356; eyes, 363;

nose, 368; teeth, 370
Amnion, 31, 195, 198, 211, 212
Amoeba, 456

Amphibia; cerebrum, 399

Anaptomorphus, 36, 153, 501
Ancient Egyptian ; sacrum, 290
Ancient Peruvians, 267
Andamanese; intermembral index, 331;
radio-humeral index, 335 ; tibio-
femoral index, 337; hair, 355; teeth,
370 ; cranial type, 461, 464, 466, 468,
473, 474; stature, 474; skeleton, 474;
skin, 474 ; hair, 474 ; eyes, 474 ;
sacrum, 288, 290; pelvis, 296, 300;
innominate index, 298
Angle ; of Camper, 243, 244, 271 ; of
Frankfort agreement, 244, 271 ; spheno-
ethmoidal, 247, 248, 270, 272 ; foramino-
basal, 247, 272, 273 ; spheno-maxillary,
247, 268, 269, 270; bregmatic, 526, 540,
541 ; frontal, 541

Angles: in crania of Simiidae, 268 etseq.;

in cranium of dog, 268 et seq.

Angular measurements ; in crania of
Australian aboriginals, 268 et seq.; in
crania of Europeans, 268 et seq.; in
crania of Cercopithecidae, 268, 271,
272 ; in a negro cranium, 271 ; in a
Kalmouck cranium, 271
Anomalies ; see Variations
Ant-eater, 25

Anterior cerebral commissure, 446, 447
Anthropodus, 510
Anthropoidea, 32
Anthropology; definition of, 1
Anthropometry ; apparatus ; selected
measurements, 343, 344; head, 343;
face, 343; body, 344; estimation of
prognathism or orthognathism, 343;
graphic representation of data and
results, 345; difficulty in estimating
femoral length, 345
Anthropomorpha, 33 (footn.)
Anthropopithecus niger ; see Chim-
panzee

Aortic branches, 223
Apertura pyriformis nasi : Chimpanzee,
108; Gibbon, 104; Orang-utan,
106

35—2

548

GENERAL INDEX

Appendix verraiformis caeei, 43, 47, 222,
225; in Gorilla, 97
Archaeopteryx, 26
Archaic gyri, 409, 410, 411
Archaic sulci, 409, 410, 411, 412
Armadillo, 25
Armenians, 368

Arteria saphena louga, 223 ; in Gorilla,
101

Arteries; in Gorilla, 98, 99, 101
Artificial deformations of crania, 254
Artiodactyla (Ungulata), 314, 315
Asteriou, 229, 230
Astragalus, 325; angle of neck, 326
Atavism, 219, 220
Auditory bulla, 23, 34
Auditory meatus, 42, 43, 45
Auriculo-nasal length, 237, 240
Auriculo-prosthionic length, 237, 240
Australian aborigines ; 263, 264, 267 ;
teeth, 139, 140, 141, 142, 369, 370;
post-orbital wall imperfect, 223 ; ironto-
squamous articulation at pterion, 223 ;
fronto-maxillary articulation in orbit,
223 ; sternum presents simian features,
225; scaphoceplialic, 252: cutaneous
musculature, 388, 384; femur, 319;
tibia, 328; sacrum, 288, 290; pelvis,
296, 300 ; innominate index, 298 ;
inter-membral index, 331 ; radio
humeral index, 335 ; tibio-femoral
index, 337 ; ear (external), 865,
366 ; nose, 368 ; cerebral characters
of, 423-433 ; as a morphological group,
461, 463, 469-471, 545; as prototypes
of the Hominidae, 462, 545; cranial
type, 461, 463, 465, 468-470, 521, 525,
529; stature, 470; skeleton, 470, 535;
skin, 471 ; hair, 355, 360, 471 ; eyes,
471 ; muscular system, 471 ; brain,
471 ; teeth, 517 ; femur, 535; extinction
of, 545

Australian spiny ant-eater, 13
Axillary muscle, 220, 381
Aye-aye ; see Cheiromys

Balkenwindung, 405
Band of Giacomini, 404
Bantu negro; sacrum, 290; pelvis, 296,
300; innominate index, 298
Base of cranium ; of Gibbon, 104
Base-line of the Frankfort Agreement,
231

Basi-nasal length, 237, 240, 241
Basi-occipital component of the cranio-
facial axis, 114-120
Basion, 229, 230
Basi-pallium, 393, 397, 398
Basi-prosthionic length, 237, 241
Bengali, 437, 438

Berbers, 366
Bicornuate uterus, 222
Birds, 16, 17 ; cerebrum, 399
Blood; in Mammalia, 19
Brain ; see Cerebrum
Branchial clefts, 219
Breadth index, 457-460 ; see also Ce-
phalic index
Bregma, 229, 230
Bregmatic angle, 540
Broca’s Stereograph, 9
Broca’s convolution, 8
Bronchi ; in Gorilla, 100
Bush Natives ( see also South African
type) ; cranial indices, 480 ; inter-
membral index, 331 ; radio-humeral
index, 335 ; tibio-femoral index, 337 ;
hair, 357, 358; sebaceous glands, 360;
steatopygia, 360 ; eyes, 362, 363 ; nose,
368; intestines, 373; liver, 374; spleen,
374 ; pancreas, 374; heart and vascular
system, 376 ; kidneys and suprarenal
bodies, 377; genitalia, 378; sacrum,
290 ; pelvis, 296, 297, 300 ; innomi-
nate index, 298; skeletal musculature,
385, 388 ; peripheral nerves, 390

Caecum, 43, 47, 49
Cagots, 366

Calcaneum, 326, 327; in Hominidae, 326;

in Simiidae, 326; in Negroes, 326, 327
Calvarial height index, 539
Camper’s facial angle ; see Angles
Capacity of the skull, 249 ; estimated by
means of a formula, 250: correlation
with cranial dimensions, 250
Capacity of the vertebral canal, 277, 278
Carnivora, 20, 24, 25, 295, 301, 448 ;

embryology of, 192, 193, 194, 205, 207
Carpus; in Gorilla, 83; of Lemur, 53
Cartilage in plica semilunaris, 362
Catarrhinae, 43
Caudate lobe of liver, 222
Cebidae, 32 ; brain-weight, 420, 421 ;
fossil, 503; ear-form, 365; placenta,
212

Central nervous system; of Lemur, 57 ;
of Cercopithecus, 66 ; of Gorilla, 88 ;
of Hominidae, 391 et seq.

Cephalic index, 258 et seq.

Cephalisation, 403
Ceratodus; teeth of, 151
Cercopithecidae, 32, 59-72; breadth index
of skull, 261 ; M. retractor oculi, 363 ;
ear-form, 365; nose, 367; fossil, 504;
placenta, 212; cutaneous musculature,
381

Cerebellum; 35, 412-415; in Australian
brains, 433; in Negro brains, 434; in
Cercopithecus, 66; in Gorilla, 90

GENERAL INDEX

549

Cerebral commissures, 398, 399, 404, 409,
412

Cerebral convolutions; in Gorilla, 89-92
Cerebral expansion, and modification in
skull form, 119, 120

Cerebral fissures ; transitory, 419, 420,
447

Cerebral gyri ; see under Cerebrum
Cerebral hemispheres, 35-39, 48, 49, 55-
57, 59

Cerebral localization ; in Gorilla, 91
Cerebral opercula ; in Gorilla, 101
Cerebral sulci, 36, 37 ( see also Cerebrum)
Cerebral sulci in brain of a Gorilla foetus,
185

Cerebral sulci ; in brains of various races;
see under Cerebrum

Cerebrum ; of Cebus, 39 ; of Cercopi-
thecus, 40, 66, 67, 68 ; embryology,
418-420; of Gorilla, 89-92; of Hylo-
bates, 40; Australian aborigines, 471 ;
African negroes, 473 ; Eurasiatics, 477;
Polynesians, 478 ; Greenlanders, 480 ;
racial variation in, 420-443 ; weight
of, 420-422, 433, 436, 443; variations
with age, 422; variations with sex,
422 ; in “ lower ” races, 423-443 ;
scheme of study, 423 ; in Australian
aborigines, 423-433; in Negroes, 433,
437 ; in white and yellow races, 437,
440; in Fuegians, Lapps, and Letts,
440; in Polynesians, 440; in Eskimo,
440, 441; in Bushmen, 441-443; with
defect of the rhinencephalon, 444-445 ;
with defect of the corpus callosum,
445—447 ; microcephalic, 447-449 ; with
defective neopallium, see microcepha-
lic; in palaeontology, 449-451, 518-
520, 527, 542 ; casts of, 449-451, 542 ;
in ancient Egyptians, 451 ; in a Mound-
builder, 451 ; inferior frontal convolu-
tion, 451 ; of Pithecanthropus erectus,
451, 518-520; of Homo primigenius,
451, 527, 542 ; of Lemurs, 35, 36, 37,
55 ; in Mammals, 19
Cervical nerves ; in Gorilla, 92
Cervical ribs, 279
Cervical spinous processes, 223
Cervical vertebrae, 223 ; in Gorilla, 101 ;

in Hominidae and Simiidae, 279
Cetacea, 20, 23, 25 ; embryology of,
205

Cheek pouches, 42, 43
Cheiromyidae, 32
Cheiromys, 35, 36

Cheiroptera, 20, 24, 25, 26 ; embryology,
194, 207

Chimpanzee ; breadth index of skull,
261

Chinese (see also Yellow races), 267,

385; sacrum, 290; pelvis, 300; brain,
439

Cingalese, 382

Cingulum ; of teeth, 148, 151
Classification ; of angular measurements,
271; of cranial deformations, 251; by
indices, 261 ; of Mammalia, 16 ; of
Primates, 32; of variations, 218, 219
Clavicle, 23, 24, 33, 49, 303
Cloaca, 21, 31 ; in Mammals, 18 ; in
Prototheria, 18
Colobus monkeys, 43
Colon, 35, 38 ; transverse, in Gorilla, 96, 97
Comparative osteology, pp. 279 et seq.
Comparative weights of various parts of
the skeleton, 275, 276, 277
Concrescence of teeth, 146, 151, 152
Condylarthra, 33; (tooth), 153; teeth of,
153

Connection of maternal and foetal
tissues, 202, 204, 206, 207
Convolution of Broca, 8
Coraco-brachialis muscle, 222
Coracoid bone, 17, 20, 21, 23
Corpus callosum, 21, 22, 23, 28 (foot-
note), 398, 399; development, 418;
defect of 443, 445-447
Corpus striatum, 392, 394-397, 399
Crania; orientation, 230, 231
Cranial air-spaces ; in Simiidae, 113
Cranial breadth ; measurement of, 237,
238

Cranial capacity, 237 et seq., 457-460 ;
in the Simiidae, 273; in the new-born
infant, 273 ; racial factors in, 273 ; in
Andamanese, 273 ; methods of deter-
mination, 273, 274 ; in relation with
cranial dimensions, 274, 275
Cranial circumference ; measurement
of, 237, 240

Cranial deformations, 251
Cranial form and pelvic-brim form, 300,
301

Cranial form and parturition, 300
Cranial height ; measurement of, 237,
238, 239

Cranial length ; measurement of, 236,
237

Cranial nerves ; in Gorilla, 92
Cranial sections, 112-121
Cranial synostosis, 20, 21
Cranial types; Australian, 461, 463,

465, 468-471 ; African, 461, 464, 466,
468, 471-473 ; Andamanese, 461, 464,

466, 468, 473, 474; Eurasiatic, 461,
464, 466-469, 474-477 ; Polynesian,
461, 464, 467, 469, 477, 478 ; Green-
land, 461, 465, 467, 469, 478-480;
South African, 461, 465, 468, 469,
480-483

550

GENERAL INDEX

Cranio-cerebral index, of Hominidae,
276, 277 ; of Simiidae, 276
Cranio-faeial axis; in Hominidae, 115;

in Mammalia, 116 ; in Simiidae, 114
Cranio-femoral index ; of Hominidae
and Simiidae, 277

Craniological descriptions ; scheme for,
232, 233
Craniology, 8, 9
Craniometer, 238

Craniometry ; principles of, 257-259
Cranium ; of Cercopitliecus, 59 ; of
Chimpanzee, 107 ; of Gibbon, 103,
104 ; of Lemur, 52 ; of Orang-utan,
105 ; hypsistenocephalic, 463 ; in
microeephalus, 447, 448, 449 ; imma-
ture, 452. 453 ; female, 454, 455 ;
senile, 453, 454 ; racial variation in,
455 ; primitive form, 456, 457 ; mor-
phological groups of 460 et seq. ;
cranial types, figs. 276-299 inclus. ;
Megaladapis, 497 ; Adapis, 500 ;
Anaptomorphus, 501 ; Mesopithecus,
502; Homunculus, 503; Oreopithecus,
504; Mesopithecus, 504; Pliopithecus,
505 ; Palaeopitheous, 506 ; Pliohylo-
bates, 506 ; Dryopithecus, 507 ; An-
thropodus, 510 ; Pithecanthropus,
512-515 ; Homo pritnigenius, 524-
534, 537-541
Creodonta ; teeth of, 153
Creodonta ; see Extinct Carnivora, 153
Criteria of distinction, 13, 14
Curvilinear measurements, 235-242
Cutaneous glands, 360-361
Cutaneous grooves on palm and sole; in
Gorilla, 100, 101

Cutaneous musculature, 59, 222 ; of
Cercopitliecus, 63 ; of Gorilla, 85
Cutaneous nerves ; in Gorilla, 92, 93
Cutaneous nerves to lower extremity ;

in Chimpanzee, 93-95
Cyclopia, 445, 446

Cynocephalus, 27 ; index of the lumbar
curve, 287
Cynopithecus, 26

Daubentonia ; see Cheiromys
Daubentonioidea, 33 (footn.)

Dacryon, 229, 230
Decidua, 196
Decidual cells, 196
Deciduata, 205

Deciduate placenta, 204, 205, 207
Deciduoma malignum, 204
Deformed crania, 251-256
Deformed pelves, 302, 303
Demi-deciduata, 205
Dental evolution; mechanical factors in,
154

Dental formula ; primitive, 150
Dentition ( see also Teeth), 22, 23, 24, 31-
34, 37, 42, 43, 45, 48, 49, 52, 60 ; in
Chimpanzee, 109 • in Gibbon, 104 ; in
Gorilla, 78, 79 ; in Lemur, 52 ; in
Orang-utan, 107

Diagnosis of cranial deformation, 256
Diagonal band of Broca, 425
Diaphragm, 18, 19
Diffuse placentation, 208
Digits, 24, 25, 33, 34, 37, 42, 43, 49,
53

Diprotodontia, 20, 22, 28
Discoid placenta, 201, 209, 212
Distinctive cranial characters ; of
Gibbon, 110 ; of Orang-utan, 110 ; of
Gorilla, 111 ; of Chimpanzee, 110
Distorted pelves ; see Deformed pelves
Distribution of artificial cranial defor-
mation, 255

Dog ; embryology of, 192, 193, 194 ;
spheno-maxillary angle of cranium,
268

Dorsi- epitrochlear muscle, 222
Dorsipallium ; see Neopallium
Dryopithecus, 507

Ear (external) ; 363-366 ; Simiidae

(Orang-utan, Gorilla, Chimpanzee),

363, 365 ; aural index, 363 ; helix,

364, 366 ; lobule, 364, 366 ; “soldered
lobe,” 364; project from head, 364,
366 ; auriculo-temporal angle, 364 ;
racial differences in form, 364, 365,
366 ; Cercopithecidae, 365 ; anti-helix,
366 ; in foetus, 161

Earliest human embryo, 195
Earth-pig, 25
Echidna, 21

Edentata, 20, 23, 25, 28, 29, 295;
embryology of, 205

Egyptians, 370, 447, 451 ; cranial

indices, 264

Embryology, 11 ; human, Section B.
155 et seq. ; of the cerebrum, 418-
420 ; Carnivora, 192, 193, 194, 205,
207 ; Cheiroptera, 194, 207 ; Ungulata,
194, 205, 209 ; Rodentia, 195, 198,
200, 204, 205, 207, 209 ; Lemuroidea,
205, 206, 208; Dog, 192, 193, 194,
205 ; Rabbit, 195, 200, 204, 205, 209 ;
Mouse, 195, 205; Hedgehog, 195, 205;
Insectivora, 195, 205, 207 ; Guinea-
pig, 198, 205 ; Opossum, 200, 205 ;
Primates ; chapter vm. ; Edentata,
205; Cetacea, 205; Metatlieria, 200,
205 ; Prototheria, 205 ; Proboscidea,
205

Empiricism in craniology, 236
Endocranial casts, 449, 527, 542

GENERAL INDEX

551

Endocranial impressions; in Simiidae,
113

Ensellure ; index of, 287, 288
Entepicondylar foramen, 33, 58, 222
Epicanthic fold; 362, 363
Epicanthus ; see Epicanthic fold
Epi-pubic bones, 21, 22, 23
Episternum, 20, 21

Eskimo ; cranial indices, 265 ; sacrum,
290 ; pelvis, 296, 300 ; innominate
index, 298 ; inter-membral index, 331;
radio-humeral index, 335 ; tibio-
femoral index, 337 ; humero-femoral
index, 340; teeth, 369, 372; intestines,
373; see also Greenlanders
Esthouians, 268

Ethmoid bone; in Simiidae, 114, 115
Ethmoidal component of the cranio-
facial axis, 115, 117-120
Eurasiatics; cranial-type, 461, 464, 466-
469, 474, 477 ; stature, 476 ; skeleton,
476; skin, 476 ; hair, 476 ; eyes, 477 ;
brain, 477

Europeans ; sacrum, 288, 290 ; pelvis,
296, 300 ; innominate index, 298 ; in-
ter-membral index, 331; radio-humeral
index, 335 ; tibio-femoral index, 337 ;
humero-femoral index, 338-340; hair,
353-360 ; eyes, 361, 362 ; ears, 363-
366 ; nose, 367, 368 ; teeth, 370 ;
cerebrum, 477 ; cranial indices, 263-
267

European infants ; cranial indices, 263
Eutheria, 20, 23, 24, 25, 28, 29, 30, 31
Evolution, 10

Extinct Carnivora ; teeth of, 153
Extinct Lemurs ; teeth of, 153
Extinct Metatheria (marsupialia), 153
Extinct Prototheria (monotremata), 153
Extinct Ungulata ; teeth of, 153
Eyes; 361-363; varieties of colour, 361 ;
of Simiidae, 361 ; sclerotic, 361 ;
variation of colour with age, 361 ;
plica semi-lunaris, 362 ; form of orbit
and vision, 362; myopia, 362;
retractor muscle, 363 ; Australian
aborigines, 471 ; African negroes,
473 ; Andamanese, 474 ; Eurasiatics,
477; Polynesians, 478; Greenlanders,
480

Facial angle; Camper’s, 3, 243, 244, 271
Facial index, 259, 261, 265, 266
Facial musculature ; of Gorilla, 84, 85
Fascia dentata, 404

Femur, 33, 311-320 ; in Gorilla, 82 ;
curvature of shaft, 311 ; angle of neck
and shaft, 311, 312; third trochanter,
313; condylar extension, 313; platy-
meria, 313-320 ; in Ungulata perisso-

dactyla, 313 ; Metatheria, 314 ;
Eutheria, 314, 315 ; Ungulata artio-
dactyla, 314, 315 ; Insectivora, 314 ;
Carnivora, 314 ; Ungulata tylopoda,
314 ; Ungulata proboscidea, 314 ;
Ungulata perissodactyla, 314 ;
Simiidae, 315; Gorilla, 316; Orang-
utan, 316 ; Chimpanzee, 319 ; Austra-
lian aboriginal, 319 ; rickety, 320 ;
Pithecanthropus erectus, 515, 516 ;
Neanderthal, 535 ; Spy, 536

Fijians ; cranial indices, 262
Fimbria, 404
Finns, 368

Fissura rhinalis cerebri, 59, 424, 433,
434, 435, 436, 437

Fissure of Sylvius ; see Sylvian fissure
Floccular fossa ; in Cercopithecus, 72
Floccular lobe ; in Cercopithecus, 72 ;
in Gorilla, 90

Flocculus ; see Floccular lobe
Flower’s craniometer, 238
Foetus ; human, see Human foetus ; of
Gorilla, 159, 160
Foramino-basal angle, 247
Forearm, 33, 49

Formulae ; for calculating the capacity
of crania, 274, 275 ; for the stature,
342

Fornix, 394, 395, 398, 404, 405, 446,
447

Fossil human remains ; see Geological
antiquity of Homo primigenius ; also
522, 523

Fossil primates ; Lemurs, 497-503 ;
Anthropoidea, 503-542 ; Cebidae, 503 ;
Cercopithecidae, 504, 505 ; Simiidae,
505-510 ; Pithecanthropidae, 510-
520 ; Hominidae, 520-542
Frankfort facial angle ; see Angle
Frontal angle, 541

Frontal-zygomatic index; see Stephano-
zygomatic index

Fronto-maxillary suture, 222, 223 ; in
Gorilla, 101 ; in Cercopithecus, 72
Fronto-parietal index, 539, 540
Fronto-squamous suture, 222, 223 ; in
Cercopithecus, 72 ; in Gorilla, 101
Fuegians, 440; radio-humeral index,
335 ; hair, 356

Galago ; adipose deposit, 361
Galeopitheeus volans, 26, 48, 49, 50
Geminated teeth, 138
Genealogical table, 31
Genealogy of the Primates, 31
Generalisations from the study of
variations, 218

Geniculate body (mesial); in Gorilla, 90

552

GENERAL INDEX

Genitalia, 377 ; hypertrophy of nymphae
in Bush and Hottentot women, 378
Genito-urinary system ; kidneys, 377 ;
of Cercopithecus (male and female),
71, 72; in Gorilla, 100
Geographical distribution, 11
Geographical nomenclature for cranial
groups, 461

Geological antiquity; of Pithecanthro-
pus erectus, 510; of Homo primi-
genius, 520, 521, 523, 544
German, 440
Glabella, 229, 230
Goniometer, 245

Gorilla, 72-101 ; breadth index of skull,
261; brain, 448-450; foetus, cere-
bral sulci, 185

Greenlanders; sec also Eskimo; cranial
type, 461, 465, 467, 469, 477, 478;
stature, 479 ; skeleton, 479 ; skin, 480;
hair, 479; eyes, 480; brain, 480;
cerebrum, 440, 441 ; extinction of,
545

Guanche; sacrum, 290
Guinea-pig; embryology of, 198
Gymnura ralflesii, 31
Gyrus A. Retzii, 405, 424, 426, 433, 434,
435, 436, 446
Gyrus geniculi, 405
Gyrus subcallosus, 425, 436

Hair : 858-360 ; in Simiidae (Hylobates,
Gorilla, Orang-utan and Chimpanzee),
353, 354; factors in growth of, 353;
absent from certain Mammals, 353;
terminal phalanges devoid of hair-
follicles, 353 ; direction of hair-tracts,
353, 354 ; of foetus, see Lanugo ;
sexual differences in amount and ex-
tent, 354; on pigmented naevi, 354;
a sign of malnutrition, 354, 355 ;
racial variations in amount and form,
355-360 ; classification, 356, 357 ;
association with skin-colour, 357 ;
peppercorn variety, 358; microscopic
appearances, 358, 359 ; index of
section, 359; follicles, 358, 359; pig-
mentation, 359; colour, 360; distri-
bution in negro races, 360 ; Australian
aborigines, 471; African negroes, 473;
Andamanese, 474; Eurasiatics, 476;
Polynesians, 478; Greenlanders, 479;
South Africans, 482
Hallux, 48
Hapalidae, 32
Harderian gland, 362
Hatteria (a reptile), 397, 398
Head-spanner, 239, 240
Heart; Cercopithecus, 70 ; Gorilla, 98,
99; Lemur, 56; Mammalia, 19

Hedgehog, 15; embryology of, 195
Height index, 259, 261, 262, 263
High degree of specialization in the
Simiidae, 120, 121
Hindu, 440 ; sacrum, 290
Hindustan ; aborigines, 360, 370
Hippocampus, 394, 395, 404, 405; in
foetal brains, 418
History of craniology, 234
History of craniometry, 235
Hominidae, 32

Homo neanderthalensis; see H. primi-
genius

Homo primigenius, 520
Homunculus, 503
Hottentots, 363

Human embryology ; section B, 155
et seq.

Human foetus; sacrum, 289; pelvis,
292, 296, 297, 299; os innominatum,
297, 298 ; thorax, 301 ; external

features, 157, 158 ; topographical
anatomy, 157, 161, 166; systematic
anatomy, 157, 171, 181
Human foetus at fifth month; physio-
gnomy, 159, 160 ; abdomen, 161 ; limbs,
161; lanugo, 161; external genitalia,
161 ; external ear, 161 ; topographical
anatomy, 166; cerebrum, 166, 184,
185; cerebellum, 166, 185; central
lobe, see Island of Reil ; Island of
Reil, 167, 168, 184 ; hippocampus,
168; stria Lancisii, 168; systematic
anatomy, 181 ; cranial bones, 181 ;
vertebral column, 181, 182; clavicle,
183 ; scapula, 183 ; carpus, 183 ;
pelvis, 183; femur, 183; fibula, 183;
external malleolus, 183; tarsus, 183;
muscular system, 183, 189 ; rhin-
encephalon, 184; insula, see Island
of lieil ; cerebral sulci, 185 ; heart,
185; thymus, 185; supra-renal bodies,
185; lung, 185; tonsils, 186; ap-
pendix caeci, 186; colon, 186; rectum,
186; liver, 186, 187; kidney, 186;
testes, 186 ; vagina, 188 ; enamel-
organ of teeth, 188; teeth, 188; con-
clusions from study of, 190, 191
Human foetus at ninth month ; phy-
siognomy of, 157, 159; trunk, 157,
158 ; abdomen, 158 ; limbs, 158 ;
hairy covering, 158; genitalia, 158;
topographical anatomy, 161 ; dimen-
sionsofhead, 162,188; cerebro-cranial
topography, 162 ; cerebellum, 162 ;
spinal cord, 162; form of spinal
curvatures, 162, 163 ; topographic re-
lations of certain viscera, etc., 163;
hyoid bone, 164; larynx, 164; thoracic
organs, 164; upper limb girdle, 164;

GENERAL INDEX

553

heart, 164, 165, 170 ; thymus, 165;
aortic arch, 165, 170; oesophagus,
165; liver, 165; Sylvian fissure, 162,

169, 178; central sulcus, 162; brain,
162, 176, 188; neo-pallium, 162, 177;
cerebellum, 162 ; spinal cord, 162 ;
levels of viscera as compared with
vertebral centra, 163, 169, 170; hyoid
bone, 164 ; larynx, 164 ; sternum, 164,

170, 174 ; diaphragm, 164 ■ clavicle,

164; scapula, 164; heart, 164, 165,
178 ; aorta, 165 ; oesophagus, 165 ;
liver, 165, 180, 188; stomach, 165,
166, 179 ; pylorus, 165 ; pancreas, 166 ;
caecum, 166, 180 ; supra-renal bodies,
166, 178, 179 ; kidneys, 166, 180 ;
ureters, 166; bladder, 166, 180; rec-
tum, 166, 180 ; uterus, 166, 180;
prostate, 166, 180 ; urinary meatus in
female, 166 ; systematic anatomy,
171 ; cerebral opercula, 169 ; epi-
glottis, 170; cricoid cartilage, 170;
tracheal bifurcation, 170; duodenum,
170; bifurcation of aorta, 170; cranial
bones, 171,172; cranial arc, 171, 173;
prognathism, 172 ; facial profile, 172 ;
tympanic bone, 172 ; inter-orbital
space, 173; nasal bones, 173; pre-
maxilla, 173 ; palate, 173 ; cranial
base, 173; endocranium, 173; verte-
bral column, 173, 174; vertebral

curvature, 174, 188 ; sacrum, 174,
175, 188; ribs, 174; sub-costal angle,
174; scapula, 174; iliac bones, 175,
176; ischial spines, 176; femur, 176;
astragalus, 176; external malleolus,
176; muscles, 177, 189; rbinencepha-
lon, 177; intra -parietal sulcus, 178;
ductus arteriosus, 178; umbilical ar-
teries, 178; thymus, 178; lungs, 179;
colon, 180; ovaries, 180; vagina, 180;
conclusions from study of, 188, 190;
classification of evidence from, 188;
pithecoid affinities, 188; vagina, 190;
specific human characters in, 188,
190

Human genitalia, 15

Human morphology, 7, 9, 10, 11, 12,
14

Human ontogeny and phylogeny, 156

Humero-femoral index ; 338-340 ; in
Simiidue, 338 ; in Hylobates, 338 ; in
Orang-utan, 338 ; in Gorilla, 338 ; in
Chimpanzee, 338; chart of, 339

Humerus; shaft, 307-309; of Simiidae
and Hominidae compared, 308; torsion
of shaft, 308, 309 ; olecranon fossa
perforated, 309 ; axis of trochlear sur-
face, 309-311

Hydrocephalus, 255

Hylobates ; placenta, 212
Hyoid bone, 35, 38 ; in Gorilla, 100
Hypocone, 149

Hyracoidea, 23, 33; see also Ungulata

Iliac bones ; in Gorilla, 82
Ilio-sacral joint; in Mammalia, 17
Imperfect post-orbital wall, 222, 223
Implantation of ovum in maternal tis-
sues, 201, 204, 206, 211
Incisor teeth ; missing in man, 140, 141
Incisura temporalis, 405
Indeciduata, 205

Index ; cranio-cerebral, 276 ; cranio-
femoral, 277 ; fronto-parietal, 539 ;
calvarial-height, 539 ; of the lumbar
curve, 286, 287 ; of lumbar height,
282 ; inter-membral, 329-333 ; radio-
humeral, 333-335 ; tibio-femoral, 336-
337 ; humero-femoral, 338-340 ; of
section of hair, 358; of ear (external),
363, 364, 365, 366 ; nasal (on the liv-
ing), 367; dental, 369, 370; orbital,
259, 260, 261, 266, 267, 268; thoracic,
301, 302; scapular, 304; pelvic, 295,
296; pelvic brim, 299, 300; sacral,
289 ; innominate, 297, 298
Indiaus of N. America, 267
Indications of indices, 261
Indices ; 257 et seq. ; cephalic, 258-262 ;
breadth, see cephalic index ; height,
259, 261, 262, 263 ; altitudinal, see
Height index ; alveolar, 259, 260, 261,
263, 264 ; prosthionic, see alveolar
index ; nasal, 259, 261, 264, 265 ; facial,
259, 261, 265, 266 ; stephano-zygo-
matic, 259, 261, 266 ; fronto-zygo-
matic, see stephano-zygomatic index;
classification, 261 ; nomenclature, 261 ;
general indications of, 261; in Simii-
dae, 261; in Gorilla, 261; in Orang-
utan, 261; in Chimpanzee, 261; in
Cercopithecidae, 261; in reference to
age, sex, and race, 262 et seq.; of
Bush natives, 262 ; of Fijians, 262 ;
of Lapps, 262 ; of Oceanic negroes,
263, 267 ; of prehistoric French crania,
263; of Javanese, 263; of aborigines
of Australia, 263, 264, 266; of Euro-
pean infants, 263 ; of Egyptians, 264 ;
of Europeans, 263, 264, 265, 266, 267 ;
of African negroes, 264, 265, 267 ; of
Eskimo, 265; of Torres Sts. Islanders,
267 ; of ancient Peruvians, 267 ; of
aborigines of Tasmania, 267 ; of
Chinese, 267 ; of Polynesians, 267 ; of
Javanese, 267 ; Indians of N. America,
267 ; of Esthonians, 268
Infra-temporal crest; of Gorilla, 78
Inion, 229, 230

35—5

554

GENERAL INDEX

Insectivora, 20, 24, 25, 26, 29, 31 ; em-
bryology, 195, 207

Insula, see also Cerebrum; morphology,
407, 409 ; simian form in Egyptian
foetus, 419

Integumentary system; in Gorilla, 100
Inter-membral index, 329-333 ; in Ho-
minidae, 329, 332; in Simiidae, 329,
332; in Australian aborigines, 331; in
African negroes, 331 ; in Andamanese,
331 ; in Europeans, 331 ; in Bush
natives, 331; in Eskimo, 332, 333; in
Lapps, 332 ; in Pygmies (African), 332
Intestines, 372, 373

Inversion of embryonic layers, 197, 198
Irregular segmentation of the vertebral
column, 280

Irrelevant cases of anomalies, 221
Ischial callosities, 42, 43, 45
Island of Reil ; see Insula

Japanese ; sacrum, 290; pelvis, 296, 300;
femur, 535

Javanese; cranial indices, 263, 267
Jews, 368

Kangaroo, 13, 22

Kidneys ; Lemur, 57 ; Gorilla, 100
Klinoceplialic crania, 252
Knee-joint ; in Gorilla, 82
Koilorachic vertebral column, 285
Krapina cranium, 522, 531-533, 539
Krapina skeletons, 522, 537
Kroo negro, 385

Kurto-rachic vertebral column, 285

Lacrymal bone, 58, 222; Chimpanzee,
108; Gibbon, 104; Gorilla, 75; Orang-
utan, 106

Lacrymal foramen, 34, 38
Lacrymo-ethmoidal suture; in Gorilla,
70

Lambda, 229, 230
Lanugo, 158, 354, 355
Lapps; 440; inter-membral index, 331;
radio-humeral index, 335 ; sacrum,
290 ; nose, 368
“Lark-heel” ; in negroes, 326
Laryngeal saccules, 225; in Gorilla, 100,
101

Larynx, 374, 375; of Mammalia, 18
Lemuridae, 32, 51-59 ; ear-form, 365 ;
brain, 409

Lemuroidea, 544; embryology of, 205,
206, 208

Leontiasis ossea, 255
Letts, 440

Limb-bones ; in Gorilla, 83
Limb-bones; of Mammalia, 17
Limb-muscles ; of Cercopithecus, 64

Limb-muscles; of Gorilla; 85-88
Litopterna, 33 (footn.)

Liver, 373, 374 ; Cercopithecus, 69, 72 ;

Gorilla, 98, 101
Lobengulism, 360
Lobus azygos irnpar of lung, 222
Locus perforatus anticus, 394-397
Lower limb ; of Lemur, 53
Lumbar height index ; in Hominidae
and Simiidae, 282, 283, 284
Lumbar index; classification by, 285;

modified form, 284, 285
Lumbar nerves ; in Gorilla, 93
Lumbar regiou of the vertebral column,

281 et seq.

Lumbar vertebrae, 281 et seq.-, of Gorilla,
80, 81 ; in infants, 284 ; sexual diffe-
rences in, 283 ; racial differences in,
283-288 ; in the Cercopithecidae, 283
Lumbo-sacral ensellure, 287, 288
Lumbo-vertebral index ; see Lumbar
index

Lungs ; of Cercopithecus, 70, 72 ; of
Lemurs, 57 ; in Mammalia, 19
Lymphatic system, 377

Macacus monkey, 27
Malays, 370, 371 ; sacrum, 290
Mammalia, 12 et seq.\ blood, 19; brain,
19 ; cloaca, 18 ; coracoid, 17 ; heart,
19; ilio-sacral joint in, 17; larynx, 18;
limb bones, 17; lungs, 19; shoulder
girdle, 17; skull, 16; teeth, 18;
ureters, 19; vertebrae, 16
Mammary glands, 21, 22, 33, 35, 38, 49,
360

Mandible ; Chimpanzee, 109 ; Gibbon,
104 ; Orang-utan, 107
Maoris, 372

Marginal pallium, 394, 397, 398, 403

Marquesas Islander, 440

Marsupialia ; see also Metatheria ;

adipose deposit, 361
Measurements ; scheme of, 236, 237 ;
cranial length, 236, 237 ; cranial
breadth, 236, 238 ; cranial height,
237, 238, 239 ; cranial circumference
of, 237, 240 ; auriculo-nasal length,
237, 240 ; auriculo-prostliionic leugth,
237, 240; basi-nasal length, 237, 240;
basi-prosthionic length, 237, 241 ;
nasi-prosthionic length, 237, 241 ;
orbital, 237, 241 ; nasal, 237, 241 ; in
projection, 241 ; angular, 242-249 ; of
capacity, 249 ; classification of, 234 ;
rectilinear, 235-242 ; curvilinear, 235-
242 ; of lumbar vertebral centra,

282

Mechanical factors; in dental evolution,
154

GENERAL INDEX

555

Mechanical production of variations and
anomalies, 220

Megaladapis (an extinct form of Lemur),
53, 497-500

Melanesian aborigines ; teeth, 137, 139,
141, 142, 369, 370, 371 ; sacrum,
290 ; pelvis, 296, 300 ; hair, 358 ;
ear-form, 365, 366 ; cutaneous mus-
culature, 382 ; skeletal musculature,
385

Melanin, 346, 347
Meso-colon ; of Cercopitheeus, 72
Mesopithecus, 504, 505
Metacone, 148

Metatheria, 20, 22, 28, 31, 295 ; em-
bryology, 205

Method of craniological description,
232 233

Microcephalus, 447-450, 512, 520
Missing links, 26, 511
Mongolian eye ; 362, 363
Mongolians ; see also Yellow races
Monotremata, 20, 21, 28, 29, 31
Mori-ori, 372

Morphology ; of the Island of Beil,
407 ; of the Sylvian fissure, 407, 408,
409

Mouse ; embryology of, 195
Mouth ; 368
Multituberculata, 21
Muscle ; dorso-humeralis, 222 ; occipito-
scapularis, 222 ; dorsi-epitrochlearis,
59, 222 ; coraco-brachialis, 222 ; omo-
cervicalis, 222 ; ischio-condylaris,
223 ; soleus, 223 ; iuterossei pedis,
223 ; ischio-condylaris in Gorilla,
101; coraco-brachialis in Gorilla,
101 ; quadriceps extensor cruris (in
Platymeria), 318, 319
Muscular system in the human races ;

378- 389 ; cutaneous musculature,

379- 384 ; muscles of expression, 379 ;
skeletal musculature, 384-389 ; Aus-
tralian aborigines, 471 ; African
negroes, 473 ; South Africans, 482 ;
in Cercopitheeus, 63 ; in Gorilla, 84 ;
in Lemur, 54, 55

Nasal bones ; in Gorilla, 76, 77
Nasal index, 259, 261, 264, 265
Nasal measurements, 237, 241
Nasal septum, 42, 43, 47
Nasalis monkey, 68, 69
Nasion, 229, 230

Nasi-prosthionic length, 237, 241
Neanderthal man, 82 ; cranium, 522,
524-527, 537-541 ; skeleton, 522, 534,
535

Negrito races, 544 ; extinction of, 545 ;
sacrum, 288

Negroes (see also African negroes), ear-
form in, 365, 366; nose (of living),
368 ; mouth, 368 ; teeth, 368, 370 ;
tongue, 372 ; intestines, 372, 373 ;
liver, 373, 374 ; spleen, 374 ; larynx,
374; vascular system, 375, 376;
thoracic duct, 377 ; kidneys, 377;
supra-renal bodies, 377 ; bladder, 377 ;
penis, 377 ; female genitalia, 378 ;
cutaneous musculature, 382, 383 ;
skeletal musculature, 385-387 ; peri-
pheral nervous system, 389 ; lumbo-
sacral plexus, 389, 390 ; sacrum, 288,
290 ; pelvis, 296, 300 ; innominate
index, 298

Nerves; cervical, in Gorilla, 92 ; cranial,
in Gorilla, 92 ; lumbar, in Gorilla, 93 ;
sacral, in Gorilla, 93 ; sympathetic, in
Gorilla, 93 ; cutaneous, in Gorilla, 92,
93 ; cutaneous, in Chimpanzee, 93,
94, 95

Nervous system (central) ; general con-
siderations, 391 ; comparative mor-
phology, 392-412 ; comparative
morphology of the cerebellum, 412-
415 ; comparative morphology of the
spinal cord, 415-418; of Reptiles,
Birds, and Amphibia, 399 ; of Proto-
' theria, 399, 400, 402 ; fissures and
convolutions, 400-412 ; sulci and
gyri, 400-412 ; factors by which
neo-pallial increase is determined,
401-403; of Eutheria, 402; cephalisa-
tion, 403 ; cerebellum overlapped by
cerebrum, 406

Nervous system; of Gorilla, 88-93;

peripheral, 389, 390
Neo-pallium (see also Cerebrum) ; 392,
397, 398-412, 423 ; of Cercopitheeus,
66-68 ; of Gorilla, 89-92
Nesopithecus, 502, 503
Neuroglia, in spinal cords of Primates,
418

New Britain ; crania, 455
New Caledonian, 382
Nomenclature of Indices, 261
Norma verticalis (of Blumenbach), 4,
227, 228, 232 ; lateralis, 227,

228 ; facialis, 228 ; basilaris, 227 ;
occipitalis, 228

Nose ; 367, 368 ; in Simiidae, 367 ;
variations with age, sex and race, 367 ;
index (in the living), 367 ; racial
variations, 367 ; classification, 367,
368 ; infantile-types, 368
Nycticebus tardigradus, 57

Obelion, 229, 230

Obliquity of forearm in extension, 309,
310, 311

556

GENERAL INDEX

Occipital operculum ; cf. references to
Sulcus lunatus

Oceanic negroes ; cranial indices, 267 ;

see also Melanesians
Olecranon fossa humeri, 223 ; in Gorilla,
101

Olfactory bulb, 394-397, 403, 405 ;
peduncle, 394-397, 403, 405 ; tract,
394-397, 403, 405
Ontogeny, 156
Ophryon, 229, 230
Opisthion, 229, 230
Opossum, 22 ; embryology of, 200
Orang-outang, sive Homo sylvestris,
1, 2

Orang-utan ; breadth index of skull,
261 ; placenta, 210

Orbit, 33, 34, 38, 49, 52, 58, 60 ;
Chimpanzee, 108 ; Gibbon, 104 ;
Gorilla, 75; Orang-utan, 106
Orbital index, 259, 260, 261, 266, 267,
268

Orbital margins ; in Chimpanzee, 108 ;

Gibbon, 104 ; Orang-utan, 106
Orbital measurements, 237, 241
Oreopithecus, 504
Orientation of crania, 230, 231
Ornithorhynchus, 21
Orthorachic vertebral column, 285
Os centrale carpi, 47
Os innominatum, 294, 297 ; index of,
291 ; in Simiidae, 294, 297 ; in
Europeans, 298 ; in Australian
aborigines, 298 ; in negroes, 298 ; in
the Bush race, 298 ; in Polynesians,
298; in Eskimo, 298; in Andamanese,
298

Osteometric board, 328
Ova ; Mammalian, 21, 22, 31
Oviducts, 21, 31

Palaeopithecus, 506

Palaeontology, 11, also Section D, pp.
496-546

Palate, 368 ; of Chimpanzee, 109 ; of
Gibbon, 104 ; of Gorilla, 78 ; of
Orang-utan, 106
Pancreas, 374 ■ in Gorilla, 97
Pangans ; see Semangs
Papuan, 385 ; see also Melanesians
Paracone, 148
Paraterminal body, 394-397
Pathological deformation of crania, 255
Pearson’s head-spanner, 239, 240
Pelvic brim index, 299
Pelvic deformations, 302, 303
Pelvic organs ; of Lemur, 58
Pelvis, 23, 24 ; of Cercopithecus, 61 ; of
Gorilla, 81 ; of Lemur, 53 ; iliac
curvature and fossae, 291 ; iliac spines,

291 ; ischial spines, 291 ; ilio-pectineal
lines of, 291 ; in rachitis (rickets),
302, 303 ; in spinal kyphosis, 302,
303 ; in sacro-iliac synostosis, 302, 303 ;
of Robert, 302, 303 ; in spinal caries,
302, 303 ; sexual differences in, 291,
299 ; parietes, 292 ; of the human
foetus, 292, 299 ; ischial bones, 292 ;
iliac crest, 292 ; sacro-sciatic notch,
292 ; sub-pubic angle, 292 ; of Simiidae,
292 ; of Cercopithecidae, 292, 294,
295 ; os innominatum, 293 ; index,
295 ; brim index, 295, 299 ; in Meta-
theria, 295 ; in Edentata, 295 ; in
Rodentia, 295 ; in Carnivora, 295 ; in
Ungulata, 295, 299; in Primates, 295,
296 ; in Simiidae, 295, 296, 299 ; racial
differences in, 299, 300; in Australian
aborigines, 300 ; in the Bush race,
300 ; in Bantu negroes, 300 ; in
Andamanese, 300 ; in Polynesians,
300 ; in negroes, 300 ; in Tasmanian
aborigines, 300 ; in New Caledonian
aborigines, 300 ; in the white races,
300 ; in the yellow races, 300 ; in
Europeans, 300 ; in Chinese, 300 ; in
Eskimo, 300 ; in the Kaffirs, v. Bantu
negroes ; in Aiuos, 300 ; in Japanese,
300

Penis, 377 ; in Gorilla, 100
Peripheral nervous system ; in Gorilla,
92, 93

Perissodactyla (Ungulata), 313
Peritoneum ; in Gorilla, 98
Peruvians (ancient), 267
Phrenology, 452
Phylogeny, 156
Pineal body, 219

Pithecanthropidae, 32, 48, 510-520 ;
femur, 312, 313, 320, 515 ; molar teeth
of, 149, 516

Placenta, 19, 35, 38, 193, 201, 204-210,
212 ; Metatheria, 22
Plagiocephalic crania, 253, 254
Platybasia, see Platybasic deformation
Platybasic deformation of crania, 254
Platycnemia, 320; associated conditions,
323; causation, 323, 324; in squatting
attitude, 325; in Simiidae, 325; index
of, 325 ; iu varieties of Hominidae,
825

Platymeria ; causation, 317-319 ; in
Hominidae, 316 ; in Metatheria and
Eutheria, 314 ; (see also Femur) ; in
Simiidae, 316
Platyrrhinae, 43

Plica fimbriata; in tongue of Gorilla, 96
Plica semilunaris, 362
Pliohylobates, 506
Pliopithecus, 505

GENERAL INDEX

557

Pogonion, 229, 230
Pollex, 37, 42, 43, 45, 49
Polybunodont theory; of teeth, 146, 151
Polynesians ; 267 ; cerebrum, 440 ;

sacrum, 290 ; pelvis, 296, 300 ; radio-
humeral index, 335 ; ear-form, 365,
366 ; teeth, 370, 372 ; cranial type,
461, 464, 467, 469, 477, 478 ; stature,
477 ; skeleton, 478 ; skin, 478 ; hair,
478 ; eyes, 478 ; brain, 478 ; innominate
index, 298

Polyprotodontia, 20, 22, 28
Popliteal femoral flattening, 319, 320
Postglenoid foramen, 58, 222
Posthumous deformation of crania, 255
Post-orbital wall, 58, 222, 223
Prehistoric French crania ; cranial
indices, 268

Primates, 20, 25, 28-154, 295, 299
Primitive cranial form, 456, 457, 521
Primitive dental formula, 150
Principles of craniometry, 257, 258,
259

Proboscidea (Ungulata), 314; embryo-
logy of, 205

Proboscis monkeys, 40, 44, 68, 69
Prognathism, 457-460
Projected measurements, 242
Proportions of limbs ; in Gorilla, 83
Proportions of segments of limbs, 327-
341

Prosthion, 229, 230

Prosthionic index; see Alveolar index

Protocone, 148, 150

Protopterus; teeth of, 151

Prototheria, 20, 28; embryology of, 205

Pterion, 229, 230

Pygmie, Tyson’s, 1

Pygmy races (see also Andamanese,
African Pygmies, Lapps, Pangans,
Semang), 462, 483-495; hair, 355,
358

Pyriform lobe, 393, 394, 399

Quadrate bone ; in Mammalia, 16
Quadrumana, 33 (footnote)

Rabbit; embryology of, 195, 200, 204,
209

Rachitis, 255

Racial variation in the cerebrum, 420-
443

Radio-humeral index ; in Australian
aboriginals, 335; in Veddahs, 335;
in Polynesians, 335; in African ne-
groes, 335; in African Pygmies, 335;
in yellow races, 335; in Andamanese,
335; in Fuegians, 335; in Hominidae,
333, 334, 335; in Simiidae, 333, 335;
in Australian Aborigines, 335; in

Lapps. 335 ; in Eskimo, 335 ; in Bush
natives, 335
Radius, 311

Rectilinear measurements, 235-242
Reptiles, 16, 17 ; cerebrum, 399 ;

shoulder girdle, 17

Respiratory system; Cercopithecus, 70;

Gorilla, 100
Rete mirabile, 57
Reversion ; see Atavism
Rhinencephalon, 35, 38, 57, 392, 393,
397, 403, 423, 424, 439, 443-445, 448
Rhinion, 229, 230
Rickets; see Rachitis
Rodentia, 20, 24, 25, 295; embryology,
195, 200, 204, 207, 209

Sacculus laryngis ; in Gorilla, 100, 101
Sacral index, 288
Sacral nerves ; in Gorilla, 93
Sacral notch, 288

Sacrum and sacral measurements, 288 ;
of Gorilla, 81; of negroes, 288; of the
Eskimo, 290; of the European, 290,
291 ; of the Lapp, 290 ; of the Mela-
nesian, 290; of the Polynesian, 290;
of the Hindoo, 290; of the Guanche,
290 ; of the Malay, 290 ; of the ancient
Egyptian, 290; of the Aino, 290; of
the Japanese, 290; curvature of, 291;
of the human foetus, 289, 291 ; dolicho-
hieric, 289, 290 ; platyhieric, 289, 290 ;
subplatyhieric, 289, 290 ; of Simiidae,
289, 290, 291 ; influence of age on
form, 289; influence of sex on form,
289, 291 ; influence of race on form,
289, 290 ; classification of sacral
forms, 290 ; of the Bush race, 290 ; of
the negro, 290; of the Andamanese,
290 ; of the Australian aboriginal,
290; of the Tasmanian aboriginal,
290; of the Bantu negro, 290; of the
Chinese, 290; of the American Indians,
290

Sauropsida, 16
Scaphocephalic crania, 252
Scapula ; of man, 303 ; of the rabbit,
303 ; of the Simiidae, 304 ; index, 304;
in Carnivora, 304; in Cercopithecidae,
304; of Cercopithecus, 61; of Lemur,
52

Scapular index, 304; in Simiidae, 305;
in Hominidae, 305 ; in the human
foetus, 305

Scapulo-spinal angle; in Simiidae, 305;
in Hominidae, 305

Scheme for eraniological descriptions,
232, 233

Scheme of eraniological description in
Simiidae, 102, 103

558

GENERAL INDEX

Scheme of craniometrical observation,
236, 237

Sclerotic coat of eyeball, 361
Sections; of crania, 112-121
Semangs; hair, 360

Sexual differences; in skulls of Gorilla,
72

Shifting of pelvic girdle (alleged), 280
Shoulder girdle, 31; of Cercopithecus,
61 ; of Lemur, 53 ; of Mammalia, 17,
18; of Protothesia, 18; of Reptiles,
17

Significance of variations, 219
Simiidae (Hylobates, Orang-utan, Go-
rilla, Chimpanzee), 32; cranio-cerebral
index, 276 ; cranio-femoral index, 277 ;
capacity of the vertebral canal, 278;
index of lumbar height, 282, 283;
fossil, 505-510, 541-544; slcin-colour,
350 ; hair, 353, 354 ; ear-form, 365 ;
nose, 367 ; teeth, 370 ; tongue, 372;
intestines, 373; larynx, 374; vascular
system, 375; muscles of expression,
379; cutaneous muscles, 381, 382;
skeletal muscles, 386, 387, 389; cere-
brum, 407, 409-412 ; cerebellum,
414 ; spinal cord, 415, 416 ; spinal
cord of, 417, 418 ; foetal brain of,
418 ; brain-weight of, 420 ; sulcus
lunatus, 432; Affenspalte, 432; and
microcephalic brains, 448-450; cere-
brum, 451 ; breadth index of skull,
261; pelvis, 292-296, 297, 299, 301,
304; sacrum, 288; cranial indices,
261 et seq. ; index of the lumbar
curve, 287
Sirenia, 20, 24, 25
Skeletal system ; of Gorilla, 79
Skeleton; Australian aborigines, 470;
African negroes, 472; Andamanese,
474; Eurasiatics, 476; Polynesians,
478; Greenlanders, 479; South Afri-
cans, 482 ; Megaladapis, 499 ; Adapis,
501; Nesopitbecus, 502, 503; Meso-
pithecus, 505; Pliohylobates, 506,
507 ; Dryopithecus, 507, 509 ; Pithec-
anthropus, 515 ; Homo primigenius,
534-536

Skin; Australian aborigines, 471; Afri-
can negroes, 473; Andamanese, 474;
Eurasiatics, 476; Polynesians, 478;
Greenlanders, 480 ; South Africans,
482

Skin-pigments; classification of human
races, 353, 346-349 ; causation of
pigmentation, 346, 347 ; mechanism
of pigmentation, 349; varieties, 348;
situation, 348; physiology of, 346-
349; distribution over the surface,
349 ; Metschnikoff’ s researches, 349 ;

Thomson’s researches, 349 ; in
Simiidae, 350; variation with age,
351 ; in new-born negroes, 351 ; in
various races, 352; variation in the
sexes, 352

Skull; of Gorilla, 72-79; Mammalia,
16, 17

Small intestine; in Gorilla, 97
Soft tissues, 346 et seq.

South African aborigines ; see also Bush
natives ; extinction of, 545 ; cerebrum,
441-443; cranial type, 461, 465, 468,
469, 480-483; stature, 482; skeleton,
482 ; skin, 482 ; hair, 482 ; muscular
system, 482; steatopygia, 483 ; external
genitalia in females, 483
Specific features of human embryology,
193, 208, 211-216

Spheno-basilar component of the cranio-
facial axis v. Basi-occipital com-
ponent

Sphenoidal component of the cranio-
facial axis, 117, 118
Spheno-ethmoidal angle, 247, 248
Spheno-maxillary angle, 247
Sphenodon ; teeth of, 151
Sphincter muscle of the anus, 22, 23
Spinal cord; in Gorilla, 417, 418; of
Orang-utan, Chimpanzee and Hylo-
bates, 418 ; of a dog, 417 ; of a
Macaque, 417 ; weight of human, 422
Spleen, 374 ; Gorilla, 97 ; Lemur, 57
Spy crania, 522, 527-531, 539-541
Spy skeletons, 522, 535, 536
Stammlappen, 392

Stature; and absolute bulk, 340; and
limb-proportions, 341 ; lower-limb
contribution to, 341, 342; upper-limb
contribution to, 341, 342; recon-
struction from length of bones, 342;
Australian aborigines, 470; African
negroes, 472 ; Andamanese, 474 ;
Eurasiatics, 476; Polynesians, 477;
Greenlanders, 479; South Africans,
482

Steatopygia, 361, 483
Stephanion, 229, 230
Stepliano-zygomatic index, 259, 261, 266
Stereograph of Broca, 9, 245, 246
Sternum, 43, 47, 223; in Gorilla, 83;
line of junction of pre- and meso-
sternum, 306; sexual differences in
length, 306

Stomach, 33, 49 ; in Gorilla, 96
Stria Laneisii, 405
Subcutaneous tissues, 360
Succession of dentitions, 145
Sulcus lunatus, 410, 423, 426, 427, 428,
429, 430, 431, 433-443, 447, 448
Supra-renal bodies, 377

GENERAL INDEX

559

Sylvian fissure; morphology, 407, 408,
‘409

Sympathetic nervous system ; in Gorilla,
93

Sympodial monsters, 208

Syncytium, 196, 201, 204, 210

Synostotie deformations of crania, 251,
*252

Syphilis, 255

Tail, 42, 43, 45 ; in human embryo, 215

Tamil, 437, 438

Tarsius spectrum, 32, 141, 206, 207

Tasmanian aborigines, 267, 370; sacrum,
290 ; pelvis, 300

Taxeopoda, 33 (footn.)

Teeth ; see also Dentition ; origin of
different types, 143; homodont, 143;
haplodont, 143; heterodont, 144; of
toothed whales, 144; of Prototheria,
144 ; of Metatheria (Marsupialia), 144 ;
monophyodont, 144; diphyodont, 143,
144; primitive cone-form, 143, 145;
successive series, 143, 145 ; of Iguana,
145 ; of Insectivora, 145 ; Trituber -
cular origin of, 146-150; Polybunodont
origin of, 146, 151 ; concrescence of,
146, 151

Teeth; see also Dentition ; of Melanesian
aborigines, 137, 139, 141, 142; of an
Egyptian, 137, 138 ; of Australian
aborigines, 139-142 ; of Oceanic-
negro races ( see Melanesian abori-
gines) ; variations in number, 136;
variations in form, 141; variations
in position, 142; missing incisor in
man, 140, 141; gemination, 138; of
Daubentonia, 141 ; of aborigines of
Jamaica, 142; of Peruvians, 142;
displaced, 142; in dermoid cysts, 142;
of Cebus, 125, 133, 136 ; of Cerco-
pithecus, 125, 134; of Chimpanzee,
130, 135; of Gibbon, 126, 134; of
Gorilla, 129, 135, 136, 138; of Lemur-
oidea, 124, 133; of Man, 131, 135-
154; of Orang-utan, 127, 134, 138,
139 (fig.), 140, 142; of Mammalia, 18;
in prehistoric races, 368; deformation,
368; in relation to diet, 368; under-
hung, 369; incisors suppressed, 369;
dental index, 369, 370 ; racial varia-
tions, 371, 372 ; degeneration, 372 ;
of extinct Lemurs, 153; extinct Carni-
vora, 153; extinct Ungulata, 153;
cingulum of, 148; talon in lower
molar, 148; of Sphenodon, 151; of
Ceratodus, 151; of Protopterus, 151;
of Megaladapis, 498; of Adapis, 500,
501 ; of Anaptomorphus, 501 ; of Neso-
pithecus, 502; of Homunculus, 503;

of Oreopithecus, 504 ; of Mesopithecus,
504, 505; of Pliopithecus, 505; of
Palaeopithecus, 506 ; of Pliohylobates,
507 ; of Dryopithecus, 507-509 ; of
Anthropodus,510 ; of Pithecanthropus,
516, 518; of Homoprimigenius, 531,
533

Telencephalon, 392, 393, 399
Temporal fossa; in Chimpanzee, 109;

of Gibbon, 104 ; of Gorilla, 78
Temporal ridges; in skulls of Gorilla, 75
Testes, 33, 49

Theory of probability applied to anthro-
pological data, 218
Theria, 20, 21

Thoracic viscera; of Lemur, 57
Thorax; sectional appearance, 301; in
Simiidae, 301; in Carnivora, 301; in
Cercopithecidae, 301 ; in Cebidae, 301 ;
in man, 301 ; in Eutherian Mammalia,
301 ; in the human foetus, 302
Thymus gland, 219 ; in Gorilla, 100
Thyroid gland; in Gorilla, 100
Thyrsocephalic crania, 254
Tibia ; 320-325 ; upper articular surface,

320, 321 ; retroversion of head, 320,

321, 322; platycnemia, 320; in fossil
Hominidae, 321-325 ; in Simiidae, 322 ;
‘boomerang’ variety, 323; in squatting
attitude, 325

Tibio-femoral index, 336; in Chimpan-
zee, Gorilla, and Orang-utan, 336; in
the human foetus, 336 ; sexual differ-
ences in, 337; racial differences in,
337

Todas, hair, 355
Tongue, 372; in Gorilla, 96
Torres Sts. Islanders, 267
Transformation of the simian into the
human skull-form, 119, 120
Transverse colon in Gorilla, 96
Trapezium, 409, 412
Trigonocephalic crania, 252
Tritubereular teeth, 68
Trituberculy ; theory of, 146-150
Trunk-muscles of Cercopithecus, 65
Tylopoda (Ungulata), 314
Tympanic region of skull ; in Metatheria,
22; in Eutheria, 23

Ulna, 311

Uncus, 433, 434, 435, 446
Ungulata, 20, 24, 25, 295, 299; embryo-
logy, 194, 209; molar teeth of, 149;
(Perissodactyla), 296, 313, 314; (Artio-
dactyla), 314, 315; (Tylopoda), 314;
(Proboscidea), 314; (Perissodactyla),
314

Unicellular condition of ovum, 192
Uniformity of human morphology, 227

560

GENERAL INDEX

Ureters in Mammalia, 19
Ursidae ; brains of, 448
Uterus, 35, 38, 49, 59

Variations, 217 et seq.

Variation in anatomical structure, 11
Variations in vertebral column, 279,
280, 281

Veddah, 535 ; radio-humeral index, 335 ;
hair, 360

Vascular system, 375-377; Lemur, 56;

Gorilla, 98
Veins in Gorilla, 99

Vertebral column of Cercopithecus,
60

Vertebral curves in Cercopithecus, 72
Vertebrae; of Lemur, 52; of Gorilla,
79, 80; of Mammalia, 16
Vertebral canal; capacity of, 277, 278;

in Gorilla, 81
Vertebral centra, 20, 21
Vertebral epiphyses, 21, 31
Vermiform appendix, 69, 72
Visual axis, 230

Vitelline circulation, 200, 202, 207, 208

Weight; of spinal cord, 422; of cere-
brum in white races, 420-422; of
cerebrum in Australian aborigines,
433; of cerebrum in negroes, 436; of
cerebrum of a Hottentot, 443; of
cerebrum of Pithecanthropus erectus,
514, 518-520; of muscles in limbs of
Gorilla, 84 ; of various parts of the
skeleton, 275, 276, 277
Whales; teeth, 144

Yellow races ; (see also Eurasiatics) ;
teeth, 370, 371; liver, 374; cutaneous
musculature, 382, 383; skeletal mus-
culature, 385, 388 ; cerebrum, 437-440 ;
radio-humeral index, 335 ; tibio-
femoral index, 337 ; hair, 358, 359 ;
eyes, 361-363 ; ear-form, 364-366 ;
nose, 368 ; mouth, 368
Yolk-sac, 193, 199, 200, 201, 209, 211,
212

NAMES OF AUTHORS QUOTED.

Abel, 509
Adachi, 348
Adloff, 150
Aeby, 83, 284
Albrecht, 140
Allen, 149
Ameghiuo, 503
Amoedo, 516
Annandale, 343, 488, 489
Anutschin, 472
Arkin, 436
Assfoat, 266
Avebury, see Lubbock
Aymard, 523

Baelz, 350, 355
v. Baer, 7, 155
Balandin, 174, 284

Balfour, 10; see also Foster and Balfour
Ballantyne, 161, 167, 171, 173, 176, 178,
179, 201, 207, 208
Bardeen, 281
Barker, 393, 417
Barlow, 201

Barnard Davis, see Davis
Bastian, 277
Bateson, 136, 217
Beddard, 145
Beevor, 92, 405
Bell, 379

van Beneden, 200
Benedikt, 249, 257, 439
Bertaux, 312
Birkner, 483
Bischoff, 185, 278, 410
Blake, 537
Blanchard, 219, 378
Bland Sutton, 176, 326, 354
Blind, 157, 173

Blumenbach, 2, 3, 4, 227, 235, 353

Boas, 274

Bolk, 92, 413, 414

Bory de St Vincent, 356, 357

Bradley, 413
v. Branco, 509
Breul, 348, 349

Broca, 8, 61, 83, 90, 230, 235, 248, 249,
250, 267, 273, 304, 308, 309, 323, 324,
353, 379, 436, 437, 476, 523
Brooks, 189
Brown-Sequard, 377
Brunsmann, 150
Bryce, 385, 387
Budin, 453
Buffon, 2, 5

Bumuller, 313, 320, 511, 516, 518, 519

Callan, 362
Calori, 436

Camper, 2, 3, 7, 235, 243, 244, 245, 246,
271

Charles, 313, 321, 322, 324, 536
Chievitz, 161, 177

Chudzinski, 363, 372, 373, 374, 377, 379,
380, 381, 382, 383, 385, 440, 441
Clapham, 440

Cleland, 115, 236, 247, 284, 482
Collignon, 322, 350

Cope, 32, 144, 146, 148, 149, 150, 152,
153, 538, 543
Cruveilhier, 372

Cunningham, 161, 170, 174, 189, 217,
238, 280, 281, 282, 283, 284, 285, 287,
290, 343, 380, 410, 419, 450, 511, 519
Cunningham Memoirs, 178, 182
Cuvier, 235

Daae, 367
Darwin, 6, 7, 379
Daubenton, 235, 248
Davis, 433, 537

Deniker, 85, 262, 265, 348, 350, 352, 361,
368, 379, 479, 482
Dereum, 440

Dixon, 470, 472, 475, 477, 479, 480
Donaldson, 420

562

NAMES OF AUTHORS QUOTED

Dorsey, 284, 285, 286
Dubois, Eugene, 32, 278, 401, 421, 451,
505-507, 510, 511, 516-510
Duchenne de Boulogne, 379
Duckworth, 138
Diirer, 243, 244
Duval, 203
Duvernoy, 85, 379
Dwight, 217, 280, 302

Eberstaller, 67, 90
Ecker, 472
Ehlers, 96

Either, 92, 93, 99, 380
Elliot Smith, 25, 28, 32, 57, 89, 140, 185,
207, 392-400, 404-410, 412-414, 418,
419, 424, 428, 481, 432, 433, 434, 447,
450, 451, 498, 508, 514, 527, 528
Elting, 281

Falconer, 506
Falkenstein, 851
Fallot, 436
Faudel, 522
Ferrier, 417
Fichte, 491
Fick, 416, 418
Filhol, 523
Fischer, 534

Flower, 8, 25, 29, 32, 132, 236, 237, 240,
260, 264, 305, 338, 353, 368, 370, 373,
374, 876, 377, 378, 385, 388, 390, 442,
443, 486, 504, 505, 506, 507
Flower and Lydekker, 124
Forel, 446, 447
Forster, 383, 385

Forsyth Major, 52, 124, 143, 150, 151,
153, 311, 496, 499, 501, 502
Foster and Balfour, 209
Fraipont, 130, 322, 522, 523, 531, 535,
538

Fraser, 138
Frerichs, 347
Friedenthal, 543
Fritz, 523

Froriep, 262, 265, 267, 272
Fuhlrott, 522

Gadow, 21, 140, 144
Gan ter, 367
Garson, 305
Gaudry, 504, 509, 510
Gegenbaur, 96, 236, 309
van Geliuchten, 393
Geikie, 521
Gervais, 151

Giacomini, 362, 385, 448, 450
Gilis, 199
Gillen, 323, 355
Goldstein, 420

Gonner, 162, 172, 262, 300
Gotte, 21
Gradenigo, 366
Gratiolet, 441
Gronroos, 87
Grubauer, 489
Griinbaum, 91
Guttinann, 136

Haddon, 10, 142
Haeckel, 152, 511
Hamy, 362, 372, 377, 523, 538
Hartmann, 379

Haswell, see Parker and Haswell

Hatch, 439

Heischmann, 150

Hepburn, 157, 313, 319, 320

Herodotus, 234

Herv6, 301, 304, 309, 437, 443

Hill, 144

His, 185, 189, 200, 209, 393, 420, 446
Hochstetter, 420
v. Holder, 537
Holl, 280, 381

Holt ; Donations to the Cambridge
Anatomy School, 45
Homer, 234
Horsley, 92
Horton-Smith, 265

Hose ; Donations to the Cambridge
Anatomy School, 40, 41, 44, 312, 336
Hovelacqu'e, 301, 304, 309, 362, 372, 377
Howes, 157
Hrdlioka, 440, 441
Hubreeht, 198, 205, 206, 207, 210
Hughes, 201

Humphry, 189, 329, 330, 331, 332, 333,
336, 338, 339, 372

Huntington, 217, 219, 220, 373, 433
Huxley, 6, 7, 8, 193, 194, 236, 248, 249,
268, 272, 293, 356, 357, 529, 538, 545

Johnston, 305, 332, 338, 356, 360, 485

Kaes, 437, 440
Kant, 1

Karplus, 425, 432
Kaup, 506

Keith, 72, 78, 87, 109, 176, 183, 189, 199,
212, 224, 273, 281, 306, 375, 387, 511
Kidd, 353, 354
King, 538

Klaatsch, 152, 311, 313, 462, 504, 511,
523, 529, 534, 537, 541, 542, 543
Koch, 443

Koganei, 290, 296, 300, 355
Kohlbrugge, 63, 92, 217, 219, 220
Kolliker, 359

Kollman, 185, 195, 199, 200, 201, 203,
205, 212, 265, 381, 393, 475, 494

NAMES OF AUTHORS QUOTED

563

Kowalevsky, 145, 155
Kramberger, 504, 522, 526, 531-533,
537, 539
Krause, 511
Kuithan, 413

Kiikenthal, 136, 144, 145, 150, 151,
516

Laidlaw, 326, 490

Lamarck, 2, 5

Landzert, 248

Lapicque, 492

Lartschneider, 381

Latteux, 480

Laura, 417

Leboucq, 536

Leche, 143, 144, 145, 152

Le Double, 177, 189, 217, 219

Lee, 250, 274, 275, 421

Lehmann-Nitz8ehe, 351

Leopold, 201, 205, 206

Lewis, 183

Linnaeus, 2

Li von, 305

Lohest, 522, 531, 535, 538
v. Lorenz, 498
Lubbock, 369

Lucae, 8, 54, 235, 236, 246
Lydekker, 140, 503, 504, 505, 506, 507,
511

Lyell, 538

Macalister, 174, 183, 189, 217-220, 309,
310, 311, 319, 470
MacCurdy, 275, 523
Magitot, 136
Magnus Hundt, 1
Makowsky, 523
Mall, 185, 197, 198

Manouvrier, 250, 275. 277, 316, 317,
321-325, 337, 341, 342, 401, 421, 440,
454, 511

Marchand, 185, 199, 203, 418, 420
Marsb, 148, 511

Marshall, 199, 200, 209, 442, 443

Martin, 246, 343, 511

Maska, 523

Matignon, 350

Matthew, 246

Maver, 538

Mayet, 354

Meckel, 7, 155, 161, 347
Mendel, 410
Merkel, 453
Metschnikoff, 349
Meyer, 492
Mikalkovics, 418

Miklucho-Maclay, 141, 355, 369, 425,
490

Milne-Edwards, 189

Minot, 185, 199, 202, 207, 208, 209, 399,
418

Montano, 490
Morison, 351
de Mortillet, 523, 538
Mott, 417
Muller, 189

Murie, 373, 378, 385, 388, 390, 442, 443
Nehring, 523

Nelson Annandale; see Annandale
Newton, 523
Nuttall, 543

Oldfield, Thomas, 150, 500
Onufrowicz, 446, 447
Osborn, 144, 146, 148, 150, 151, 398,
399, 500, 501
Owen, 212, 507, 523

de Palissy, 235
Papillault, 275
Parker, 436

Parker and Haswell, 16, 32, 33, 199
Parsons, 63, 189, 224, 374, 380
Paterson, 81, 280, 281, 288, 289, 290,
291, 470, 472, 474
Patten, 57, 58

Pearson, 217, 238, 240, 342, 343, 456,
494, 541
Peters, 195, 201
Petrie, 458
Pfister, 422
Pick, 417
Pohlig, 506
Poirier, 311, 312
Poll, 249
Popowsky, 379
Potter, 310, 311

Pruner-Bey, 323, 351, 358, 362, 377,
537, 538
Psymsza, 268
de'Puydt, 522

Quain, 306

de Quatrefages, 523, 538

Ranke, 245, 277, 278, 422, 511, 519,
538

Rauber, 364
Ravenel, 283, 284
Regnault, 369
Reichert, 200, 209

lietzius, 8, 57, 67, 235, 260, 405, 440,
444

Rivers, 349

Robinson, 195, 201, 202, 203, 207, 210,
488, 489
liodet, 311
Rokitanski, 523

564

NAMES OF AUTHORS QUOTED

Rolleston, 425
Romanes, 353

Rose, 144, 150, 151, 152, 370, 371
Rosenberg, 141, 280, 281
Riidinger, 443
Rupe, 54, 189, 379
Riitimeyer, 143
Ryder, 147

St Hilaire, 235, 309
Sappey, 189
Sarasin, 491, 492, 494
Sauvage, 523

Schaafhausen, 8, 523, 538
Schafer, 423

Schlosser, 145, 505, 509, 510
Schmerling, 523
Schmidt, 145
Schoetensack, 402, 545
Schwalbe. 32, 113, 144, 145, 3(14, 366,
511, 522-524, 533, 534, 537-540
Sclavunos, 374
Scott, 149
Seggel, 2G7
Seitz, 440

Selenka, 105, 138, 139, 140, 195, 196,
197, 19H, 201, 202, 203, 20G, 207, 210,
211, 212, 213, 214, 215, 21G, 529
Series, 372
Sewell, 17G, 326, 374
Shattock, 176, 326
Sherrington, 91

Shrubsall, 305, 332, 338, 480, 484
Skeat, 859, 488, 489, 490
Sorby, 34G, 348
Soren-Hansen, 350, 479
v. Spec, 195, 197, 198, 203
Spencer, 323, 355
Sperino, 92
Spigel, 235

Spitzka, 423, 440, 441, 443
Spleiss, 522
Stewart, 359
Stieda, 217
Stilling,. 267

Strahl, 207, 208, 210, 212
Strassmann, 178
Stratz, 462
Stroud, 413
Stuart, 385, 388
Sue, 331

Sutton, see Bland Sutton
Swanzy, 362
Symes, 491

Taeker, 150
Thomas, 150

Thompson, 381

Thomson, 176, 180, 182, 183, 262, 289,
292, 297, 298, 299, 320, 321, 322, 345,
349, 351, 359, 458, 482
Telford, 450

Testut, 217, 219, 363, 523
Thane, 306, 420, 421, 433
Tims, 144, 146, 150, 151, 153
Tizzoni, 347

Tomes, 107, 129, 141, 152, 370, 371,
531

Topinard, 130, 152, 236, 244, 249, *250,
263, 265, 266, 273, 295, 301, 326, 331,
340, 353, 364, 366, 367, 370, 371, 436
v. Torok, 257

Turner, 8, 81, 139, 140, 171, 205, 206,
209, 236, 240, 248, 251, 284, 285, 289,
290, 296, 298, 299, 305, 313, 319, 329,
331, 333, 335-338, 340, 341, 369, 373,
376, 379, 383, 385, 386, 387, -389, 446,
470, 478, 489, 511, 519, 523, 544
Tylcfr, 10

Tyson, Dr Edward, 1, 2, 7, 235
Vali, 367

Verneau, 296, 298
Vesalius, 234, 311
Virchow, H., 417

Virchow, R., 8, 248, 251, 347, 490, 491,
511, 517, 523, 538
Vogt, 7, 537, 538
Volkov, 325

Wagner, 538

Waldeyer, 215, 415, 417, 435, 436, 444,
511, 619

Walkhoff, 523, 531, 533
Warda, 3(56, 367
Waruschkin, 272
Weber, 519
Weinberg, 440
Weisgerber, 301
Welcker, 189, 248, 280, 421,

Weldon, 217
Wernicke, 90

Wiedersheim, 54, 221, 354
Wilson, 140, 144
Windle, 63, 85, 137, 141
Winge, Herluf, 33
Wood, 389
Woodhull, 451

Woodward, 144, 150, 151, 501
Wyman, 443

Zittel, 523, 537

Zuckerkandl, 152, 370, 371, 395, 405,
433

CAMBRIDGE : PRINTED BY J. AND C. F. CLAY, AT THE UNIVER8ITY PRESS.

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