NERVOUS SYSTEM. VERTEBRATA. 439 



region presents very striking contrasts in this series of 

 Orang-brains, close examination shows that its fundamental 

 plan is identical in all. 



D. 654. Two casts of the cranial cavity o an Orang-Outang 

 (Simla satyrus). 



Note the prominent orbital keel. 



D. 655. Two casts of the cranial cavity of a smaller Orang- 

 Outang (Simla satyrus). 



D. 656. The left cerebral hemisphere of a Gorilla (Anthropo- 

 plthecus gorilla) (figs. 246, 247, 250). 0. C. 1338 I/. 



D. 657. The remainder of the left half of the same brain. 



0. 0. 1338 i/. 

 D. 658. The right half of the same brain (figs. 248, 249). 



This excellently preserved brain (obtained from a young 

 male Gorilla some 33 Ibs. in weight and 34 inches high) is 

 probably by far the best specimen of its kind to be found 

 anywhere. And, so far as the writer is aware, it has never 

 been adequately described, although Kiikenthal and Ziehen 

 (who seem to imagine that " Troglodytes savagii" [the old 

 legend on this specimen] is a Chimpanzee) and Beddard 

 (Proc. Zool. Soc. 1899) have published brief notes con- 

 cerning it. 



The brain of the Gorilla is the largest found in any Ape, 

 and (so far as this large collection of Anthropoid brains is 

 concerned) presents a much stronger resemblance to the 

 human brain than does that of any other Ape. According 

 to Keith, there is a very marked difference in the cranial 

 capacity of the two sexes (Proc. Zool. Soc. 1899, p. 299). 



In general shape the brains of the three great Anthropoid 

 Apes exhibit a strong resemblance. This is best shown by 

 the casts of the cranial cavity. The hemispheres of the 

 Oraug present a more exaggerated oval outline, when 

 viewed from above, than do those of either of the two 

 Anthropopitheci ; and of the latter the frontal regions of 



