APES, MONKEYS, AND LEMURS. 23 



The largest and most hideous of the tribe is the mandril (Papio maimon) 

 of the forests of Western Equatorial Africa, remarkable for its robust build, 

 stump-like tail, highly swollen and fluted muzzle, and the brilliant tints of 

 blue and scarlet with which the naked portions of the face and buttocks of 

 the adult males are decorated. In South Africa the genus is represented by 

 the chacma (P. porcarius), which is a more soberly-coloured species, with a 

 tail equal in length to half the body ; while the yellow baboon (P. babuin) 

 of West Africa may be taken as an example of species in which the tail is 

 still longer. Although found in the upland forests of Mount Kilima-Njaro, 

 the dog-faced baboons are more generally inhabitants of open, rocky districts, 

 where they go about in large parties, inflicting severe damage on the products 

 of the cultivated lands, and fiercely attacking all intruders on their domains. 

 In their diet they are well-nigh omnivorous, feeding not only upon fruits and 

 cereals, but likewise devouring large numbers of lizards and insects, in 

 search of which they turn over stones with their fingers. The late Sir R. 

 Burton wrote that in the jungles of Usukuma these baboons "are the terror 

 of the neighbouring districts ; women never dare to approach their haunts ; 

 they set the leopard at defiance, arid, when in a large body, they do not, it is 

 said, fear the lion." 



As already stated on page 12, the monkeys of the New World differ from 

 their Old World cousins in having three in place of two 

 pairs of premolar teeth in each jaw ; the number of molars New World Mon- 

 being the same in both. In consequence of these and other keys. Family 

 differences, the New World monkeys, which do not range to Cebida. 

 the north of tropical America, are referred to a separate 

 family group, under the name of Cebidce. These monkeys are further charac- 

 terised by the absence both of cheek-pouches and of naked callosities on the 

 buttocks, while the tail, when long, is frequently, although by no means in- 

 variably, prehensile. The thumb is quite incapable of being opposed to the 

 other digits, but all the fingers and toes have flattened nails. In the nose 

 the partition between the two nostrils is very broad, so that the nostrils 

 themselves are widely separated, and frequently diverge to a great extent 

 from each other. The upper molar teeth have very short crowns, with the 

 four tubercles arranged obliquely, and the external surfaces of the outer pair 

 flattened and fluted, while the inner ones are distinctly crescent-shaped. 



So different, indeed, are the American monkeys which attain their maxi- 

 mum development in the tropical forests of Brazil from the Old World forms, 

 that it is quite possible they may trace their origin to a totally independent 

 source. They may be divided into ten genera, some of which comprise a 

 very large number of specific representatives. 



The half-dozen species commonly called, from their loud nocturnal cries, 

 howlers constitute a genus characterised by the massive, un- 

 wieldy body, the pyramidal head, long and somewhat dog-like The Howlers 

 muzzle, the massiveness of the angle, or hinder part of the (Alouatta). 

 lower jaw, and a remarkable thickening of the throat due to 

 the enlargement of the so-called hyoid bones into a thin bony capsule of 

 large size. It is owing to the development of this capsule that the howlers 

 are enabled to utter the discordant yells with which they make night hideous 

 to all travellers in the forests of Tropical America. All the species have a large 

 beard and whiskers, but the colour of the hair is subject to great specific 

 variation. In the red howler (A. seniculus), for instance, the head, neck, 

 limbs, and tail are dark chestnut-brown, and the back and_ sides of the 



