712 MANUAL OF ZOOLOGY. 



which are directed downwards, and are protected by pads of 

 callous horny integument. The stomach is complex, but the 

 manyplies is wanting. As regards their further characters, the 

 head of all the Camdida is destitute of horns in both sexes ; 

 the nostrils can be closed at the will of the animal; the upper 

 lip is hairy and partially cleft ; and the red blood- corpuscles 

 are oval. 



The family of the Camelidcs is represented in the Old World 

 by the Camels (Came/us), and in South America by the Llamas 

 and Alpacas (Auchenia). There is also an extensive series of 

 Tertiary forms, one of which (viz., Protolabis} is specially in- 

 teresting as possessing the full number of upper incisors, namely, 

 three on each side of the jaw. 



The true Camels are peculiar to Asia and Africa, and two species are 

 known, distinguished from one another by the possession of a double or 

 single adipose hump on the back. The African or Arabian Camel (Camelus 

 Dromedarius) is often called the Dromedary, and has only one hump on 

 its back. The two toes are united together by the callous sole ; and the 

 chest, shoulders, and knees are furnished with callous pads, upon which 

 they rest when they lie down. The hump is almost entirely composed of 

 fat, and appears to act as a kind of reserve supply of food, as it is noticed 

 to diminish much in size upon long journeys. The Camel can likewise 

 support a very prolonged privation of water, as the paunch is furnished 

 with large cells, which the animal fills when it has access to water, and 

 then makes use of subsequently as occasion may require. The structure 

 of the Camel adapts it admirably for locomotion in the sandy deserts of 

 Arabia and Africa ; and as it is very docile and good-tempered, it is 

 almost exclusively employed as a beast of burden in the countries in which 

 it occurs. 



The Bactrian Camel (C. Bactrianus] is distinguished by the possession of 

 two humps ; but in other respects it does not differ from the Dromedary. 

 It is found in Turkestan, Persia, Mongolia, and Thibet. The two species 

 are said to breed together, and the hybrid offspring is stated to be occa- 

 sionally fertile. The place of the Camels is taken in the New World b;" 

 the Llama and Alpaca, with two other nearly-allied forms. These anima's 

 form the genus Auchenia, and are in many respects similar to the trie 

 Camels. They are distinguished, however, by having no hump upon tie 

 back, and by the fact that the two toes are not conjoined and supported by 

 a callous pad, as in the Camels, but are separate, with separate pads, and w:th 

 strong curved nails. The neck is long and the head comparatively snull, 

 whilst the upper lip is mobile and deeply cleft vertically. The Llamas ire 

 chiefly found in Peru and Chili. They live in flocks in mountainous 

 regions, and are much smaller than the Camels in size. The true Llami is 

 kept as a domesticated animal, and used as a beast of burden, its wild form 

 being known as the "Guanaco." The Alpaca is still smaller than the 

 Llama, and is not very unlike a sheep, having a long woolly coat. It is 

 partially domesticated, and the wool is largely imported into Europe. Its 

 wild form is the so-called " Vicuna." 



b. Tragulida. This group comprises certain small Rumi- 

 nants, the so-called " Chevrotains " ( Tragulus\ which have been 



