440 



PHYSIOLOGICAL SERIES. 



the Gorilla are fuller and less Cercopithecoid than those 

 of the Chimpanzee. On the whole the shape of the Gorilla's 

 brain approximates nearest to that of Man, whereas that 

 of the Orang most resembles the lower .Ape-form. 



Each of the three types is provided with a prominent 

 orbital keel, which is probably slightly more pronounced in 

 the Orang's brain than in that of the other genus *. 



Fig. 246. ( X .) 



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As in the Orang and Chimpanzee, there is a very wide 

 range of variation in the arrangement of the different parts 

 of the brain, especially in those regions in which the human 

 brain differs from the Simian f. 



Upon the base of the brain the posterior rliinal fissure is 

 retained in its entirety with a diagrammatic elejirne.-s, 

 which is rarely seen in Man (although I have often seen 



* In the literature of this subject many erroneous statements will be 

 found in regard to this point. 



f In order that the student should not draw erroneous conclusions as to 

 the nature of the brain in the Anthropoid Apes from the examination of 

 solitary specimens, the Museum Committee has generously acceded to 

 my request that a valuable set of Anthropoid brains be purchased imin 

 the Zoological Gardens. Thus a series of specimens, which is probably 

 unique in its completeness, is availiible for comparison. For it is the 

 apparently fortuitous variations in the Anthropoid Apes which point th. u s .\ 

 or the possibility of human evolution. 



