696 MAMMALIA [CH. 



but on the last joints of the fingers and toes. The stomach has no 

 psalterium, but both the rumen and reticulum have a large number 

 of water-cells, that is deep pouch-like outgrowths in which a quite 

 undrinkable fluid is stored. It will be noted that all the peculi- 

 arities of the structure of the Camel which have just been mentioned 

 are directly related to the exigencies of a life on arid, sandy wastes. 

 Thus the diverging toes and leathery pad on the foot enable them 

 to secure a broader surface of the yielding sand on which to support 

 the animal's weight : the humps are a provision of food and the 

 water-cells in the stomach contain a supply of fluid to serve the 

 animal in its long wanderings from oasis to oasis over the desert. 

 The Arabian Camel is only known in the domesticated state, but 

 the Bactrian Camel ranges wild over some of the more inaccessible 

 regions of Central Asia. 



It is a remarkable and interesting fact that we find some 

 members of the Camel tribe in South America. These animals, the 

 Llama, Auchenia glama ; the Vicuna, A. vicugna ; the Alpaca, 

 A. pacos; and the Huanaco, A. huanacos; live in the Andes. They 

 have no humps but possess long fleeces which are used for making 

 cloth. The skeleton of one of these animals is almost indistinguish- 

 able from that of a Camel, and they have the same stupid, stubborn 

 ways as their relatives in the Old World. It is curious to see in 

 the stomach the same provision as is found in the Camel, although 

 water is, as a rule, plentiful enough where the Llama lives. 



The higher Ruminants are divided into two main groups accord- 

 ing to the character of their horns. In the CERVIDAE or true Deer 

 the horns are bony outgrowths of the frontal bones. The horns are 

 shed every year and are nearly always branched. They may be 

 termed antlers to distinguish them from the true horns of the 

 Bovidae. The antlers are usually confined to the male, but in the 

 Reindeer, Rangifer tarandus, which is called the Caribou in Canada, 

 they also occur in the female. When the antler has attained its 

 full growth the blood supply ceases and the skin peels off. In a 

 rim round the base called the "fur" absorption takes place, so that 

 the greater part is easily detached. In the Cavicornia or BOVIDAE, 

 the core of the horn is an unbranched bony outgrowth into which 

 air spaces continuous with the cavity called the frontal sinus of the 

 skull often extend. This core is permanent and is covered by a hard 

 horny sheath made of compacted hairs. Two small families occupy 

 an intermediate position, these are the GIRAFFIDAE, represented by 

 the Giraffe, Girqffa camelopardalis, and the Okapi, Okapia johnstani, 



