QUADRUMANA. 



201 



manous type is manifested still more strongly 

 by the narrowness and length of the sacrum, 

 its smaller curvature, and its parallelism with 

 the spine. A peculiarity is observable in the 

 position of the last lumbar vertebra with rela- 

 tion to the iliac bones ; these rise on either 

 side to, and are partially joined with that ver- 

 tebra, so that it might almost be reckoned as 

 belonging to the sacral series. 



The false vertebrce, viz. the sacral and coc- 

 cygeal, are seven in number. Of these, only 



the first two have their transverse processes 

 fully developed, and united to the iliac bones ; 

 and hence the trunk is less firmly connected 

 with the pelvic arch, and is consequently 

 more in need of additional support from the 

 anterior extremities than in man. This pecu- 

 liarity, together with the general disposition 

 of the vertebral column of the Chimpanzee, 

 shows that the animal is not designed to walk, 

 as the human subject, on his hinder legs, but 

 that it is chiefly a quadruped. 



Fig. 122. 



Skeleton of the Mandrill. (Original, Mus. Zoo/. Soc. Amsterdam.) 



In the same way, the pelvis of the Chim- 

 panzee differs from that of man in all those 

 particulars which characterise theQuadrumana, 

 and which relate to the imperfection of their 

 means of maintaining the erect position. The 

 iliac bones are long, straight, and expanded 

 above the outside, but narrow in proportion 

 to their length ; the posterior surface is con- 

 cave, for the location of the glutaei 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 su- 

 perior aperture is elongated and narrow, so 

 that the whole of the sacrum and coccyx is 

 visible on a front view. The tuberosities of 

 the ischia are broad, thick, and curved out- 

 wards. The pubic bones are broad and deep, 

 but flattened from before backwards. In 

 this general conformity with the quadru- 

 manous type, there is, however, a provision 

 for a more extended adherence of the glutsei 



muscles in a greater breadth of the ilia, be- 

 tween the superior spinous processes, which 

 also incline forwards more than is observable 

 in the lower genera of Simice ; and it may 

 thence be inferred that the semi-erect position 

 is the most easily maintained in the Chim- 

 panzee. 



In the Mandrill the general disposition of 

 the vertebral column is much more remote 

 from the form of man y and approximates to 

 the form of the Carnivorous Mammalia. In 

 the cervical vertebrae, the transverse pro- 

 cesses have a triangular form, and offer an- 

 teriorly a vertical ridge similar to that which 

 appears in most of the Mammalia as a distinct 

 apophysis. In the dorsal vertebrae, the spinal 

 processes of the nine anterior are inclined 

 backwards, of the three posterior forwards : 

 consequently they offer an opposite direction, 

 which is wanted in the vertebral column of the 

 human subject and in the higher genera of 

 monkeys, but which exists generally in the 



