THE CHIMPANZEE AND ORANG UTAN. 351 
probable, as in the skeletons of the young Chimpanzee preserved in the Hunterian 
Museum, after the four lumbar vertebre, there remain only seven for the sacrum and 
coceyx. Of these vertebre only the first two have their transverse processes fully deve- 
loped ; with reference to which it is interesting to remark, that in the adult Chimpanzee 
only the two superior sacral vertebre are united to the iliac bones ; and hence the trunk 
is less firmly connected with the pelvic arch, and consequently is more in need of ad- 
ditional support from the anterior extremities, than in Man. 
The pelvis of the Chimpanzee differs from that of Man in all those particulars which 
characterize the Quadrumana, and which relate to the imperfection of their means of 
maintaining the erect position. The iliac bones are long, straight, and expanded out- 
wardly above, but narrow in proportion to their length ; the posterior surface is concave 
for the lodgement of the glutei muscles ; the anterior surface nearly flat, and stretching 
outwards almost parallel with the plane of the sacrum. The whole pelvis is placed more 
in a line with the spine than in Man: its superior aperture is elongated and narrow, so 
that the whole of the sacrwn and coccyx is visible on a front view. The tuberosities 
of the ischia are broad, thick, and curved outwards. The pubic bones are broad and 
deep, but flattened from before backwards. With this general conformity with the 
Quadrumanous type, there is, however, a provision for a more extended attachment of 
the glutzi muscles, in a greater breadth of the ilia between the superior spinous pro- 
cesses, which also incline forwards more than is observable in the inferior Simie ; and 
it may thence be inferred that the semi-erect position is more easily maintained in the 
Chimpanzee. i 
An important difference between the Chimpanzee and Orang is manifested in the 
relative size and strength of the lower extremities, in which respect the Chimpanzee 
claims a closer relationship to Man. Both animals, however, exhibit as permanent 
conditions, proportions of the inferior extremities which are transitory in the human 
subject: in the Orang they have the curtailed proportions which they present in the 
human feetus of six months’ gestation ; in the Chimpanzee they retain the same relative 
size as in the yearling infant. It is, however, a remarkable and interesting fact, that 
the lower extremities instead of being shorter in proportion to the trunk in the young 
Chimpanzee are longer, their adult relations arising from the increased development of 
the trunk and anterior extremities, which are thus made fit for the vigorous acts of 
climbing ; and in relation to which a corresponding increase of the inferior extremities 
would have been detrimental : so that the immature Chimpanzee tends to the great pro- 
totype of animal organization in two ways, viz. a disproportionate magnitude of brain 
and cranium, and an imperfect development of trunk and arms, which are both, how- 
ever, circumstances peculiar to its nonage. 
The femur of the Chimpanzee is slightly bent in the anterior direction, as in the 
human subject: the neck of the bone has the same comparative length, but stands out 
more obliquely to the shaft. The whole of the body of the bone is flatter or more com- 
BPAL2 
