68 APES AND MOXKEYS. 



unfrequently bright-coloured, afford another character by wliich we can at once 



distiuguislx an Old World monkey from any and all of its American cousins. Their 



use is to afford a comfortable rest for the body in the upright sitting posture 



assumed by the monkeys and baboons of the Old World. 



Chesk Another feature absolutely peculiar to the monkeys and baboons 



PoucHes. Qf ^Q Qij World, although by no means common to the whole of 



them, is the presence of those pouches in the cheeks, with which all who have fed 



tame monkej's must be perfectly familiar. These cheek-pouches are formed by 



folds in the skin, and when empty lie flat on either side of the face. They can, 



however, be so distended as to contain a large quantity of food, and then stick out 



pi-ominently on either side, so as to communicate a peculiarly bloated appearance 



to the face. The possession of these pouches must ob\-iously be a great advantage 



to the monkeys in which they are found, since by their means a large quantity 



of food can be hurriedly gathered, stowed away, and aftervvai-ds eaten at leisure in 



some place of security. It might, indeed, be ui-ged that the monkeys which do 



not possess these convenient receptacles appear to get on in life quite as well as 



their relations who are thus provided : and that, therefore, these pouches are of no 



real advantage. To this it may be replied that such Old World monkeys as have 



no cheek-pouches feed much more on leaves and shoots than on fi-uits ; and that 



they are furaished ^-ith a peculiarlj' complex stomach in which this food can be 



rapitlly stowed away pre\'iously to undergoing complete digestion. 



With regard to the limbs of the Old World monkeys and baboons, 

 Limbs. * '' 



it may be observed that the anus never present that gi'eat excess in 



length over the legs which we have seen to be the case among the Man-like Apes ; 



and the legs may, sometimes, be the longer of the two. The thumb of the Old 



World monkeys and baboons can in all cases be fully opposed to the fingers, 



except, of course, in the African species in which it is either absent or inidimentary, 



and therein have another mai'ked point of difference from the American gi-oup. 



Finallv. the skeletons of all membere of the present group may 



Breast-bone. . ' . . . . a r j 



be readily distinguished from those of the Man-like Apes by the 



breast-bone being narrow and flattened from side to side, instead of broad 



and flattened from back to front. Moreover, all of the species have a central bone 



in the wrist, — a characteristic they have in common with the gibbons and orangs 



among the Man-Uke Apes. 



Such, then, are the leading features by wliich the monkevs and 

 Distribution. , , « . 



baboons of the Old World (fomiing a larger gi-oup than any other 



in the order) are distinguished from the gi"Oups immediately above and below 

 them in the zoological scale ; and the reader who has followed us carefully thus far 

 ought to be able to tell at once whether any particular monkej' that is set before 

 him should or should not be included in the present group. When we speak of the 

 members of this gi-oup occupj-ing a position immediately below that of the Man- 

 like Apes, we must guard oureelves from conveying the idea that the one can in 

 any sense be regarded as the ancestor of the other. The chfference in the structure 

 of the molar teeth of the two gi-oups is alone sufiicient to prove that this cannot be 

 the case ; those of the Man-like Apes being of a more primitive type than are those 



