480 THE ANATOMY OF VERTEBEATED ANIMALS. 



hates the artictilar 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 characteris- 

 tically human saddle shape. The pollex is longest and 

 strongest in proportion in Hylobates ; its length in propor- 

 tion 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 Chim- 

 panzee it has about one-third the length of the manus. 



The pelvis differs but little from that of the Cynomorpha 

 in Hylobates. In the other genera the pelvis is still 

 elongated. The antero-posterior diameter of the brim of 

 the i^elvis 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 forwards in the Chim- 

 panzee, 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 An- 

 thropomorpha. The femur of the Goi-illa 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 



