THE BABOONS. 249 



guished from their New World cousins, described in the previous 

 pages, by many important and obvious characters. The parti- 

 tion dividing the nostrils is narrow, instead of broad, and the 

 openings of the nostrils themselves are directed downwards and 

 outwards. Certain genera possess also sacs formed by disten- 

 sible folds of the skin in the cheeks. These " cheek-pouches " 

 serve as a storing-place by the side of the jaws, for food which 

 they cannot masticate at the moment. When this store is dis- 

 posed of, the folds of skin come together again and give no 

 indication of the presence of the pouch, which, moreover, 

 when full does not interfere with the mastication of other food 

 in the mouth, or with the utterance of the animal's usual cries. 



The hind-limbs are never shorter than the fore- ; they may 

 be equal in length, but they are generally somewhat longer, the 

 animal being more or less quadrupedal, or very partially erect 

 in gait. Their thumb is not invariably present, but when it 

 is, it is always opposable to its fellow digits. The great-toe is 

 never rudimentary, and is never, as it is in Man, the longest, 

 but is the shortest digit of the foot, and it is capable of free 

 motion to and from the others. All of the digits possess nails. 

 The length of the foot among this group approximates more to 

 the proportions of the foot in Man. The hairs on the arms 

 and fore-arms are directed downwards from the shoulder to the 

 wrist. 



The tail in this family varies very much ; it may be long or 

 short, or even externally absent, but it is never prehensile. All 

 the species, however, possess '' callosities," or hard fleshy pads 

 — often of large size — on the buttocks or seat, which, like the 

 naked skin of the face, are usually brilliantly coloured and 

 often of large size. The perineal region and organs are at 

 certain periods, especially in the females, subject to great tur- 

 gescence and brilliant coloration. 



