CHAP. XVII.] THE BRAIN OF QUADRUMANA. 



297 



organ over so as to examine its base, the orbital or under 

 surface of these lobes is found to be distinctly concave, as it 

 is in most of the larger Monkeys and Apes. Just behind 

 these parts, the lower terminations of the two Temporal 



FIG. 116. Brain of a Human Idiot. (Vogt, after Theile.) This brain, examined 

 by Theile, weighed only 10*6 oz. (300 grammes). With the exception of one, it is the 

 smallest Male Idiot's Brain whose characters have been recorded. 



This figure is placed here for comparison with that of the brain of the Chimpanzee ; 

 the letters of reference being the same in each of them. 



Lobes approach rather close to one another (fig. 118), and 

 between them are two ' Corpora albicantia,' as in Man. 



The Sylvian Fissure in the Chimpanzee as well as in 

 the Gorilla (fig. 117), and the Orang (fig. 121), is much 

 less horizontal than it is in Man. In this respect it pretty 



