1899.] Dil. A. KEITH ON TUB CHIMPANZEES. 299 



and utters a cry begiuuing with a low hoo, Jioo. gradually raising it 

 in volume to a loud climax, I do not think her cry differs from 

 that of the young Anthrojjojnthecus nirjer in character ; what is 

 peculiar in her cry may be put down to her more advanced age. The 

 Chimpanzee cry is very different from the howl of the Gorilla; 

 " Johanna " does not beat her breast, as the Gorilla does, when in 

 temper. She allows her keeper, only, to handle her ; she is vicious 

 towards others and takes her revenge on an offender by suddenly 

 throwing handfuls of litter at him from the floor of her cage. She 

 has never been given an opportunity of manifesting any nest- 

 building habit, and the experiment seems well worth trying. On 

 making her escape on one occasion she was found carryiug away 

 large pieces of wood on her shoulder. 



She is fed mostly on fruit. A day's rations consists of : — 



2 dozen bananas. 



1 „ oranges. 



1 „ raw eggs. 



I „ apples. 



Lemons. 



Carrots. 



Coffee, tea, port wine. 



Toast and sandwiches. 



When given an opportunity, she caught, plucked, and ate a 

 sparrow, but she rejects no pellets from the stomach, as was the 

 case with " Sally." 



She sleeps on her side and spends the day sitting on a broad 

 box, with her legs spread out in front and her arms on her belly. 



There is a very marked difference between the size of the brain 

 of the Gorilla and Chimpanzee. The average cranial capacity of 

 seven adult female Gorillas I found to be 450 c.c. ; of ten similar 

 Chimpanzees 364 c.c. ; bat although the average is greater in the 

 Gorillas, the highest of Chimpanzees exceeded the lowest of the 

 Gorillas, so that the size of brain is not a feature that can be used 

 to discriminate the one from the other. The average cranial capacity 

 of six adult male Gorillas is 530 c.c. ; of sixteen male Chimpanzees 

 405 c.c. The smallest Gorilla skull had a greater capacity than 

 the largest Chimpanzee. The largest Chimpanzee skull measured 

 460 c.c. The cranial capacity appears to be diagnostic for the 

 males of those animals. An important distinction appears in the 

 size of the brain as in the general appearance of those Anthropoids ; 

 the sexual difference is much more marked in the Gorilla than in 

 the Chimpanzee. 



The cranial capacity of those animals, stated in c.c, may be 

 taken as representing the brain-weight, stated in grammes ^ ; but 

 in comparing the relative size of the brains of the Gorilla and 

 Chimpanzee a greater deduction has to be made from the brain of 

 the Gorilla than from that of the Chimpanzee, owing to the much 



' Keitu. Journ. Anat. & Physiol. 1895, u. s., vol. ix. pp. 282-303. 



