390 VERTEBRATE ZOOLOGY 



fined to arid regions of the Old World. Camels are not known in 

 the wild state; all are domestic or feral. The ancestral history of 

 the camel family is now almost as well worked out as that of the 

 horse. Proverbial for the camels are two characters: that of living 

 for long periods without water, and the use of the fatty humps for 

 food when compelled to fast. Both of these characters may be 

 considered as adaptations for desert life and have made it a highly 

 valuable beast of burden and transport across the arid trails of the 

 Asiatic and African deserts; on this account they have earned the 

 cognomen "ships of the desert." The camel is very valuable for 

 its hair, which is used in making fabrics highly prized for their rich- 

 ness, softness, and wool-like characters. The llamas are creatures 

 with camel-like characters, but more generalized in several re- 

 spects; they might be called the camels of the New World, for 

 they are native to South America. They are of value chiefly for 

 their rather thin hair, which is coarser than that of the camel 

 and is the material out of which are made vicuna or alpaca 

 fabrics. The llama has the disgusting habit when irritated 

 of forcibly spitting the contents of its stomach at the object of its 

 annoyance. 



The deer family is a very large one and includes such well-known 

 types as elk, moose, reindeer, etc. They are characterized by the 

 possession of antlers in the male sex, and in the reindeers in both 

 sexes. The antlers vary in degree of elaborateness in the different 

 genera, ranging from the small, unbranched horns, as in Cervulus, 

 to the complex branching antlers of the elk (Fig. 199, D). In all 

 cases they are solid bony structures, as opposed to the hollow horns 

 of the Bovidse. About sixty species of deer are known, the ma- 

 jority of which are Old World forms. The moose is the Icing of the 

 deer family,. on account of its great size and its fighting quahties. 

 The reindeer is the most northerly of the deer, occupying circumpolar 

 territory. The musk-deer is an exceptional type in that it has no 

 horns, but instead is possessed of long, sharp tusks, probably used 

 in digging roots for food. 



The giraffe family (Fig. 199, E) is a small family of highly spe- 

 cialized ruminants distinguished by their great height, long neck, 

 and slender legs. The horns differ from all others in that they are 

 merely prominences of the frontal bones of the skull covered with 

 skin and hair. Africa is the home of the giraffe, as well as that of the 



