58 APES AND MONKEYS. 



upright forehead, the whole skull strikes one as approaching the human type far 

 more nearly than do those of the other apes. This must not, however, be con- 

 sidered as an indication that the gibbons are of a higher type than the other 

 Man-like Apes, since the contrary is clearly demonstrated by their long arms and 



THE WHITE-HANDED GIBBOX. 



the callosities on the buttocks. The resemblance of their skulls to the human 

 type is, indeed, merely a superficial one, due to the circumstance that small animals 

 must necessarily have proportionately larger brains than the larger members of 

 the same group ; and also to the absence of the strong ridges which are necessary 

 for the powerful skulls of the larger forms, but would be quite useless in their 

 smaller cousins. The superficial human-like characters of the skulls of the gibbons 

 are, however, to a great extent destroyed by their long slender tusks, or canine 



