differ from the Cynomorpha
the following characters: They are especially arboreal animals,
which habitually assume a semi-erect posture, supporting
the weight of the fore-part of the body upon the ends of
the fingers, or, more usually, upon the knuckles. There is no
tail. The thigh and the leg are, respectively, shorter than
the arm and the fore-arm. The dorso-lumbar vertebrae are
seventeen or eighteen in number, and their spines are not inclined
toward a common point. They develop no interlocking
mammillary and accessory processes. The sacrum contains
more than three anchylosed vertebrae. The thorax is rather
broad than laterally compressed, and the sternum is flattened
from before backward, and wide. The axis of the head of the
humerus is directed more inward than backward, and the upper
part of the shaft is not bent as in the Cynomorpha.
radius is capable of complete pronation and supination.
The relative proportions of the incisor teeth are the same
as in Man; that is to say, the inner upper incisors and the
outer lower incisors are larger than the others. The crowns
of the upper and lower molars have the same patterns as those
The caudal muscles are small or absent. When the pollex
has a flexor tendon, that tendon is not a slip given off from
one common to the flexor pollicis
and flexor perforans,
The plantaris does not pass over a pulley
furnished by the calcaneal process, as in the Cynomorpha;
and the flexor brevis
has an origin from that process. The peronoeus quinti digiti
has not been observed.
There are three well-marked genera of Anthropomorpha-
and perhaps a fourth, Gorilla,
may be advantageously separated from the lastnamed.
the Orang, has the smallest distributional area,
being confined to the islands of Borneo and Sumatra; Hylobates,
the Gibbons, of which there are several species, is found
over a considerable area of Eastern Asia and the islands of the
Malay Archipelago. The Chimpanzee
with only in the intertropical parts of West Africa.
The Gibbons are those Anthropomorpha
which are most
nearly allied to the Cynomorpha.
They possess ischial callosities,
and the nails of the pollux and hallux, only, are broad
and flat. The arms are so long that the points of the fingers
readily touch the ground when the animal stands upright, as
it very readily and commonly does. The Gibbons also run
with great swiftness, putting the sole of the foot flat on the
ground and balancing themselves with their long arms.
they are essentially arboreal animals, leaping from
bough to bough of the trees in the forests which they frequent
with marvellous force and precision. The manus is longer
than the pes, and the antibrachium considerably longer than
the brachium. The Gibbons do not exceed three feet in
height; their heads are small, and their bodies and limbs
None of the other Anthropomorpha
have callosities, and
the nails of all the digits are flattened. They are all heavier
in make, with proportionally shorter limbs and larger heads
than the Gibbons. In the Orangs, which rarely attain a stature
of more than four feet and a half, the arms are very long,
their span, when outstretched, being nearly double the height
of the animal. The brachium and the antibrachium are equal
in length. The long and narrow pes is longer than the equally
narrow manus, and the sole cannot be placed flat upon the
ground, but the animal rests upon the outer edge of the foot
when it assumes the erect posture. This posture, however, ia
quite unnatural, and the Orangs cannot run as the Gibbons
do, but swing themselves along upon their long arms, as it
were upon crutches.
The pollex and the hallux are both short, the latter remarkably
so; and the hallux is not uncommonly devoid of a nail.
The palmar and plantar aspects of the digits are naturally concave,
and they cannot be completely straightened.
The Chimpanzee attains a stature somewhat greater than
that of the average Orang. The span of the arms is about
half as much again as the height. The antibrachium is about
as long as the brachium. The manus is equal to, or a little
longer than, the pes; and these parts of the limbs are not so
elongated, or so curved, as the corresponding parts of the
Orang. The sole can be readily placed flat upon the ground,
and the Chimpanzee easily stands or runs erect. But his favorite
attitude is leaning forward and supporting himself on
the knuckles of the manus. Both the hallux and the pollex
are well developed and possess nails.
The Gorilla exceeds five feet in height and may reach five
feet six inches. The span is to the height as about three to
two. The brachium is much longer than the antibrachium.
The pes is longer than the manus, and both are much
broader than in the other Anthropomorpha.
of this circumstance and of the greater development of the
heel, the erect posture is easily maintained, but the ordinary
attitude is the same as that assumed by the Chimpanzee. The
hallux and the pollex have well-developed nails. The basal
phalanges of the three middle digits of the foot are bound
together by the integument.
With respect to the skeleton in the Anthropomorpha,
Gibbons have the spinal column nearly straight, with a very
open vertebro-sacral angle. In the Orangs the dorso-lumbar
vetebrae form a curve, which is nearly as much concave forward
as in a new-bom child. In the Chimpanzee the spinal
column begins to exhibit the curvatures which are characteristic
of the adult human subject; and these are still more
marked in the Gorilla.
The spinous process of the second cervical vertebra is
bifurcated in the Chimpanzee, but this human character does
not appear in the others.
In the Gibbons there are usually eighteen dorso-lumbar
vertebrae; but in the other Anthropomorpha
the number is
ordinarily seventeen, as in Man, or may be reduced to sixteen.
The Orang has the human number of twelve pairs of ribs,
but the Chimpanzee and Gorilla have thirteen, and the Gibbons
may possess fourteen pairs of ribs. The thorax is wide,
and the sternum broad and flat. In the Orang it may ossify
from a double longitudinal series of centres, as sometimes happens
In the Gibbons the transverse processes of the last lumbar
vertebra are not exceptionally broad, and do not unite with
the ilia. But in both the Chimpanzee and Gorilla they are
wide, and become more or less closely connected with the ilia.
The last lumbar vertebra may become anchylosed with the
sacrum in the Gorilla. All these conditions of the last lumbar
vertebra are occasionally met with in Man.
The sacrum is broad, and contains not fewer than five
anchylosed vertebrae, but its length always exceeds its breadth
(whereas its breadth is equal to, or exceeds, its length, in Man),
and its anterior curvature is but slight. The short coccyx is
made up of not more than four or five vertebrae. In the skull,
the proper form of the brain-case is always more or less disguised
in the adult males, by the development of crests for
muscular attachment, or of the orbits and the supraorbital
ridges. In the Gibbons and Chimpanzees, the latter are
large, but the sagittal crest is absent, and the lambdoidal
small. In the Orang, the brow-ridges are small, so that the
true form of the forehead is seen better than in the other
Apes, but the sagittal and lambdoidal crests are strong. In
the old male Gorilla the sagittal and lambdoidal crests, and
the supraorbital ridges, are alike enormous. The frontal sinuses
are large, and extend into the brow-ridges both in the
Gorilla and Chimpanzee. The jaws are largest in proportion
to the brain-case in the Gorilla and the Orang; smallest in
some varieties of Chimpanzee.
In all the Anthropomorpha
the transverse is much less
than the longitudinal diameter of the cranial cavity. The
roofs of the orbits project into the frontal portion of the braincase,
and diminish its capacity by causing its floor to slope
from the middle line obliquely upward and outward. The occipital
foramen is situated in the posterior third of the base
of the skull, and looks obliquely backward and downward.
The frontals meet in the base of the skull over the ethmopresphenoidal
suture in the Gibbons and in the Gorilla, as in
the Baboons; but not in the Chimpanzee or the Orang. The
alisphenoids unite suturally with the parietals, as is the rule
in Man, in the Gibbons and (usually) in the Orangs; but, in
the Chimpanzee, the squamosal unites with the frontal and
separates the alisphenoid from the parietal, as happens, exceptionally,
in Man. The nasal bones are flat and early anohylosed
together, in the Gibbons, Orangs, and Chimpanzees. In the
Gorilla the nasal bones are distinctly convex from side to side,
and rise above the level of the face. None of these Apes have a spina nasalis anterior;
and, only in the Siamang, is there a
rudiment of the mental prominence in the mandible. The
premaxillo-maxillary suture persists beyond the completion of
the second dentition in all but the Chimpanzee, in which it
disappears before that period. The epiotic region is never
developed into a distinct mastoid process; and there is an ossified
styloid process only occasionally in the Orangs. The
palate is long and narrow, the alveolar margins being nearly
parallel, or even diverging anteriorly. The zygomatic arches
are strong, wide, and curved in two directions.
The proportion of the length of the basi-cranial axis to
that of the cerebral cavity does not fall lower than the ratio
of 10 to 17 in any of the Anthropomorpha.
The body of the hyoid approaches the form of that of Man
most nearly in the Orang. In the other genera it is more excavated
The scapula of the Orang is most like that of Man, especially
in the proportion of the supra-and infra-spinous fossae,
in the proportional length of the anterior and the posterior
borders, and in the angle made by the spine with the vertebral
margin. In the other genera the posterior border is
longer in proportion than in Man, and the spine of the scapula
cuts the vertebral margin more obliquely. After the Orang's,
the scapula of the Gorilla comes nearest to that of Man.
On the other hand, the long and straight clavicle of the
Orang is least like that of Man.
The head of the humerus loses the backward inclination
which it has in the lower Apes, and becomes directed upward
and inward, as in Man. The radius and ulna are curved,
and leave a wide interosseous space. There are nine bones
in the carpus in both Hylobates
but only eight
in the Chimpanzee
surface presented by the trapezium for the pollex is almost
globular. It is evenly convex in the Chimpanzee; but, in the Gorilla, it has
the characteristically human saddle shape. The
pollex is longest and strongest in proportion in Hylobates;
its length in proportion to that of the manus being in H. syndactylus
as three to seven. In the Gorilla, the pollex has
rather more than one-third the length of the manus; in the
Orang and Chimpanzee it has about one-third the length of
The pelvis differs but little from that of the Cynomorpha
In the other genera the pelvis is still elongated.
The antero-posterior diameter of the brim of the pelvis greatly
exceeds the transverse, the tuberosities of the ischia are
strongly everted, and the pubic symphysis is very long, the
arch being correspondingly reduced; but the ilia are wider
and more concave forward in the Chimpanzee than in the
Orang, and in the Gorilla than in either.
In the female Chimpanzee, which is of about the same size
as the male, the dimensions of the basin of the pelvis, and, of
its outlets, are greater than in the male, though the general
form and absolute length of the pelvis are the same in the two
sexes. The female Gorilla is much smaller than the male, and
the pelvis is shorter in proportion, but the intersciatic measurement
of the outlet is absolutely as great as in the male,
and the transverse diameter of the brim is nearly as great.
As, at the same time, the antero-posterior diameter is much
shorter, the brim of the pelvis of the female is much more
round. The female Orangs, also, are smaller than the males.
The basin of the pelvis is relatively, but not absolutely, larger
in all its dimensions, and the brim rounder.
The femur of the Orang has no round ligament, and differs
in this respect from the same bone in the other Anthropomorpha.
The femur of the Gorilla resembles that of Man, most
especially in the projection of the articular surface of the inner
condyle beyond the outer.
The length of the whole foot to that of the tarsus is in Hylobates
, as thirty-five to ten, and the proportion is about
the same in the Orang; in the Chimpanzee it is as twentyfour
to ten; and, in the Gorilla, about the same (twenty-three
to ten in the specimen measured).
The hallux has not more than one-fourth of the length of
the foot in the Orang; in the Gorilla less than five-twelfths
in the Chimpanzee and in Hylobates a little more.
In the second digit of the pes of the Orang and the Chimpanzee,
the phalanges, taken together, are longer than the
metatarsal bone of the digit; in the Gorilla, they are about
equal in length to the metatarsal. The calcaneal process is
longest, strongest, and broadest, in the Gorilla. In the astragalus
the articular surface for the tibia is broadest in the Gorilla; but,
in this Ape, as in the others, it is inclined a little inward
when the foot is in its natural position; and the surface
for the external malleolus is oblique, and looks upward as well
It is a mistake, however, to suppose that the disposition
of these surfaces has any thing to do with the more or less
marked tendency of the plantar surface to turn inward, and
of the outer edge of the pes to be directed downward, which
is observable in all the Anthropomorpha
. This tendency is
the result of the free articulation between the scaphoid and
the cuboid, on the one hand, and the astragalus and the calcaneum
on the other; the consequence of which is, that the distal
portion of the pes, with the first-mentioned bone, being
pulled by the tibialis anticus,
easily rotates round its own
axis, upon the surface presented by the astragalus and calcaneum.
This ready inversion of the sole must as much facilitate
climbing, as it must interfere with the steadiness of the
foot in walking.
The distal surface of the ento-cuneiform is much inclined
inward in all the Anthropomorpha
and is convex from side to
side, or subcylindrical. The metatarsal bone of the hallux presents
a corresponding articular concavity to this surface, and
has a great range of motion in adduction and abduction. The
inward inclination of the articular facet of the ento-cuneiform,
and its consequent separation from the facet upon the mcsocuneiform
for the second digit, is greatest in the Orang, in
which the hallux is habitually directed at right angles to the
long axis of the foot. The distal phalanx of the hallux is not
unfrequently absent in the Orang.
All the Anthropomorpha
possess certain muscles which
are not usually found in Man, though they may occur as varieties
in the human subject. These are the levator claviculae,
(Not actually described in the Gorilla, and absent in some Cbimpanzees.)
and the abductor ossis metacarpi quinti digiti
. They are also devoid of two
muscles which are usually present in Man-the extensor primi
(The former muscle is said to be present by several anatomists in the
Chimpanzee and other Apes; but what they have taken for it is the metacarpal
division of the extensor ossis metacarpi.
) and the peronoeus tertius
. The former of
these is sometimes, and the latter frequently, wanting in the
The flexor accessorius
appears to be regularly absent in Hylobates
and, in the majority of cases, in the
Chimpanzee. The transversus pedis
seems to be absent in the
Orang, but it is present in the other Anthropomorpha.
Many muscles which exist both in these Apes and in Man
have different origins in the former. Thus, the soloeus
only a fibular head, and takes no origin from the tibia. The flexor brevis digitorum pedis
never arises altogether from the
calcaneum, but a large proportion of its fibres spring from the
tendons of the deep flexors. The calcaneal head furnishes the
tendons for the second, or the second and third, digits. The
interosseous muscle which lies on the tibial side of the middle
digit of the pes, usually arises from the fibular side of the second
metatarsal as well as from the tibial side of its own metatarsal,
and its origin lies on the dorsal side of that of the fibular
interosseous muscle of the second digit. Hence, of the socalled
which are visible on the
dorsal aspect of the pes) two belong to the middle digit, and
one, to the second and fourth digits respectively; which is
the same arrangement as that which obtains in the manus.
The flexor pollicis
is more or less closely connected with the flexor communis perforans,
or with that part of the muscle
which goes to the index digit. The connection is slightest in Hylobates,
the origins of the two muscles, only, being united.
It is most extensive in the Orang, in which no tendon goes to
the pollex. The same complete loss of the flexor pollicis,
a thumb-muscle, occasionally takes place in the Gorilla; but
in this animal, as in the Chimpanzee, the rule appears to be,
that the flexor pollicis
unites at its origin with part of the flexor perforans,
and that the fleshy fibres converge to a common
tendon which divides into two, one for the pollex and
the other for the index. In Hylobates,
the short head of the biceps brachii
arises from the pectoralis major,
and the adductor
and transversus pedis
form but one muscle.
The flexor longus hallucis
takes an origin from the external
condyle of the femur in the Orang; and the pectoralis
arises by three distinct slips.
Some of the muscles in the Anthropomorpha
their insertion, or in the extent to which they are subdivided,
from what is usual in the corresponding muscles of Man.
Thus the extensor ossis metacarpi pollicis
ends in two distinct
tendons one for the trapezium, and the other for the base of
the metacarpal bone of the pollex. That part of the tibialis
which goes to the metatarsal of the hallux is usually
very distinct, and is sometimes reckoned as a separate muscle,
the abductor longus hallucis.
In the Gibbons and in the Orang, there is a complete set
of deep extensors for the four ulnar digits, the tendons of the extensor indicis
and extensor minimi digiti
supply the third and fourth digits.
In the Gorilla and Chimpanzee each of these muscles have
but a single tendon, as is the usual arrangement in Man.
The interossei of the hand are each divided into two muscles
with distinct tendons-a flexor brevis primi internodii
an extensor brevis tertii internodii.
The division is less obvious
in the Orang than in the other Anthropomorpha.
the tendon of the flexor perforans pedis
only to the fifth digit, and is not directly connected with that
of the flexor longus hallucis,
which supplies the other four
digits. In the Orang, also, the tendons of the two muscles are
separate; but the flexor perforans
suppHes the second and the
fifth digits, and the flexor hallucis
the third and fourth. It
gives no tendon to the hallux. In both the Chimpanzee and
the Gorilla, a very large tendon is given to the hallux by the flexor hallucis
, and it also supplies the third and fourth digits.
The tendon of flexor longus digitorum
is but slightly connected
with that of flexor hallucis
, and its divisions go to
the second and fifth toes. In both the manus and the pes of Hylobates
a muscle occurs which is not, at present, known in
any other Mammal. It arises from the second metacarpal or
metatarsal bone, and is inserted by a long tendon into the preaxial
side of the ungual phalanx of the second digit; it may
be termed "abductor tertii internodii seaundi digiti."
The Orang, in like manner, stands alone in possessing a
small but distinct opponens hallucis.
be borne in mind that these statements respecting the myology
of the Anthropomorpha
are based upon my own dissections (sometimes supplemented
by those of Duvernoy and other anatomists) of particular specimens.
Endless varieties will no doubt be met with by those who carry their inquiries further.)
The volume of the brain, in the Orang and in the Chimpanzee,
is about twenty-six or twenty-seven cubic inches; or
about half the minimum size of a normal human brain. In the
Gorilla, the volume rises to near thirty-five cubic inches. In
the Gibbons the brain is very much smaller; and the Siamang,
among these, is remarkable for the short posterior lobes of the
cerebrum, which, in this anthropomorphous Ape, do not overlap the
cerebellum as they do in all the others.
The cerebral hemispheres are higher in proportion to their
length in the Orang than in the other Anthropomorpha;
in all, they are elongated and depressed, as compared with
those of Man. The frontal lobes taper off anteriorly, and their
inferior surfaces are excavated from without downward and
inward, in correspondence with the projection of the upwardly
convex roofs of the orbits into the cranial cavity. The posterior
cornu of the lateral ventricle is always well developed,
and contains a prominent hippocampus minor
An occipito-temporal or "external perpendicular"
sulcus is always present. It is most nearly obliterated in
the Orangs. All the gyri of the human brain are represented
in the cerebral hemispheres of the Chimpanzee; but they are
simpler and more symmetrical, and larger in proportion to the
brain (see Figs. 21 and 22). The fissure of Sylvins is less inclined
backward, and that of Rolando is placed more forward
than in Man. The insula has simpler and fewer radiating sulci,
and is not completely hidden by the temporal lobe. Only the
second, third, and fourth annectent gyri appear upon the surface.
The first remains folded upon itself, and gives rise to
the characteristically simian occipito-temporal or external perpendicular
sulcus. The occipito-parietal sulcus, on the inner
face of the hemisphere, is much more nearly perpendicular
than in the human brain. The corpus callosum is relatively
smaller; the septum lucidum is very thick, and the precommissural
fibres are well developed. The vermis is small in
proportion to the lateral lobes of the cerebellum, and the flocculi
are relatively small, and lie below the latter.
The whole cerebellum is larger in proportion to the cerebral
hemispheres; the latter being to the former, as 8 1/2 to 1 in
Man, but as 5 3/4 to 1 in the Chimpanzee. (It must be recollected
that the brains of young anthropomorphous
Apes, only, have been examined. Perhaps this has to do with the absence of
mineral deposits in the pineal gland of the Apes.) The nerves are
larger in proportion to the brain than in Man. There are no corpora trapezoidea
, such as exist in the lower Mammals, and
the corpora albicantia
In all the Anthropomorpha,
the inner incisors are larger
than the outer, in the upper jaw; smaller in the lower jaw.
There is a diastema, though it is often but small in the female
Chimpanzees. The canines are large and strong, and may be
grooved longitudinally on their inner sides. The premolars
have three roots in the upper jaw, two in the lower. The
crowns of the middle molars, above, have four cusps, and an
oblique ridge which extends from the antero-external to the
postero-iaternal cusp; and those of the middle molar, below,
have five cusps, as in Man. The crown of the anterior premolar
in the lower jaw is pointed, and has a long, sharp, oblique
anterior edge as in the Cynomorpha.
In the Gibbons, the permanent canine emerges contemporaneously
with, or before, the last molar; but, in the other Anthropomorpha,
the last permanent canine is cut, ordinarily,
only after the appearance of the last molar.
In the Orang the circumvallate papillae of the tongue are
arranged in a V, as in Man. In the Chimpanzee they are disposed
like a T, with the top turned forward. The Chimpanzee
and the Siamang have a uvula, but the Orang has none.
The stomach of the Chimpanzee is very like that of Man; but
in the Orang the organ is more elongated, with a round cardiac
and more tubular pyloric portion. An appendix vermiformis
is found in the caecum of all four genera. In the
Chimpanzee and Gorilla, the origin of the great arteries from
the arch of the aorta takes place as in Man. In the Orang,
they are sometimes disposed as in Man; while in other specimens
the left carotid comes off from the innominata, and only
the subclavian of the left side arises directly from the aorta.
the latter arrangement appears to obtain.
The kidney has only a single papilla in Hylobates
Only one species of Hylobates
, namely, the Siamang, is
known to possess a laryngeal sac. This is globular, and communicates
by two apertures, situated in the thyro-hyoid membrane,
with the larynx. In the Orang, Chimpanzee, and Gorilla,
enormous air-sacs result from the dilatation of the lateral
ventricles of the larynx. These dilatations extend down, in
front of the throat, on to the thorax and even into the axillae,
and sometimes open into one another in the middle line.
In the adult male Chimpanzee the penis is small and slender,
and terminates in a narrow and elongated glans. The
testes are very large, and the communication between the
tunica vaginalis and the peritonaeum is completely closed.
The glans penis of the Gorilla is button-shaped. In the
Orang it is cylindrical, and the testes are situated close to the
inguinal canal, which has been found open on one side, and
closed on the other. An os penis is developed in the males.
The females have the clitoris large, and the uterus, which
is undivided into cornua, resembles that of the human subject.
The placenta of a Chimpanzee foetus, 11 1/2 inches long, was simple,
rounded, 3 1/2 inches in diameter, and 0.6 inch thick in the
centre. The umbilical cord was inserted near one of its edges.
The proportions of the limbs to one another and to the
body do not sensibly change after birth; but the body, limbs,
and jaws, enlarge to a much greater extent than the brain-case.
The amount of variation in the characters of the skull
among the Chimpanzees, Gorillas, and Orangs, is exceedingly
remarkable, especially if taken in connection with their very
limited areas of distribution.
Of the four genera of the Anthropomorpha,
are obviously most remote from Man, and nearest to the Cynopithecini.
The Orangs come nearest to Man in the number of the
ribs, the form of the cerebral hemispheres, the diminution of
the occipito-temporal sulcus of the brain, and the ossified
styloid process; but they differ from him much more widely
in other respects, and especially in the limbs, than the Gorilla
and the Chimpanzee do.
The Chimpanzee approaches Man most closely in the character
of its cranium, its dentition, and the proportional size
of the arms.
The Gorilla, on the other hand, is more Man-like in the
proportions of the leg to the body, and of the foot to the
hand; further, in the size of the heel, the curvature of the
spine, the form of the pelvis, and the absolute capacity of the