258 FIRST LESSONS IN ZOOLOGY. 



cies, but a number of races which have descended from 

 several fossil species; the name Bos taurus is simply,then, 

 a conventional name. 



The ox is succeeded by the giraffe (Fig. 256), with its 

 long neck, which renders it the tallest of all quadrupeds. 



The last family of hoofed mammals,, the Camelidte, com- 

 prises the camels of the Old World, and the llama and 

 vicuna of South America. In the camels the upper lateral 

 incisors are present; the stomach is less distinctly divided 

 into four chambers; the third stomach, as such, is wanting, 

 though the second stomach has deep cells, the so-called 



"water-cells," which, according to 

 Huxley, " serve to strain off from the 

 contents of the paunch, and to retain 

 in store, a considerable quantity of 

 water; " thus the camel is popularly 

 said to store up a supply of water in 

 its stomach for its march over deserts. 

 The toes have very large, thick pads, 

 t "Mr !i while the hoofs are reduced to nail- 



^-"VS* lit \ , r '>< 



like proportions. In the camel the 

 foot-pad is common to all the toes, 

 but in the llama (AitcJienia) of the 



FIG. 256.-Head of Giraffe. Eagtcrn Andeg each toe has a dist i nc t 



pad, besides the claw. TIae llama in a wild state keeps to- 

 gether in herds; from early times it has been also domesti- 

 cated and used as a beast of burden, and for its Avool, 

 chiefly in Peru and Chili. It is rather larger than a sheep, 

 with the form of a camel. The huanaco is probably the 

 wild form of the domesticated llama (Auchenia lama], 

 while the vicuna is perhaps the wild form of the alpaca 

 (Auchenia pacoa). 



The Flesh-eat iny Mam-mal*. The change from a grazing, 

 cud-chewing, meek, timid, hoofed beast to a clawed, 

 sharp-toothed, ferocious, flesh-eating creature, like a lion 

 or cat, is a marked one. And here the adaptation of struc- 

 ture to the needs and habits of the animal is no less re- 



