598 Dynamic Theory. 



the chimpanzee, and we find the latter, relatively to the other parts, far 

 the larger. Owing to the great development of the anterior and pos- 

 terior lobes, it entirely covers up the cerebellum behind and the olfac- 

 tory lobes in front. The convolutions are also far more numerous and 

 complex. Beside these features of obvious distinction there are others 



FIG. 335 .Top of Brain of Lemur 

 (titenops Tardigradus). 

 FIG. 336. Base of same. 



located internally. In the pig 

 there is no posterior cornu of 

 the lateral ventricle, and of 

 course no hippocampus minor. 

 In the chimpanzee there are 

 both, and well developed. There 

 are no other animals beside men 

 and apes that possess anything 

 FIG. 335. FIG. 336. like the posterior cornu, except 



the delphinidse ( or dolphin and porpoise family ), which show a mere 

 beginning of it. (Fig. 316.) If the brain of man is to be put into a 

 separate sub-class from that of the pig, then is the ape. entitled to the 

 same distinction. The Rabbit is placed in the sub-class below the Pig, 



FIG. 337. Base of Brain of Ourang 

 Outang. 



1. Olfactory nerve. 



2. Optic nerve and chiasm- 



3. Pons Varolii. 



4. Medulla oblongata. 



5. Cerebellum. 



O. Post orbital convolution covering 

 Island of Reil in part. 



8'. Mid-orbital Convolution. 

 ' . 



-Ent-orbital 

 O'". Ect-orbital 



but the difference between their 

 brains is less than that between 

 the Pig and the Ape. The 

 bodily structure of the man-like 

 Ape also separates him from 

 the other animals of the sub- 

 class gyrencephala, and connects 

 him with man. (See Chap. 2.) 

 Whatever line of distinction is 

 drawn between man and the 

 higher apes on account of brain, it is equally proper to draw between 

 the highest and lowest families of the quadrumana. The brain of the 

 Lemur,* fig. 335, presents more points of anatomical inferiority to that 

 of the Chimpanzee or Gorilla than theirs do to Man's. The cerebrum 

 does not nearly cover the cerebellum ; the convolutions are not numer- 

 ous; the lateral lobes of the cerebellum are not relatively well developed, 



FIG. 337. 



