80 



FOOD 



leaves, grasses, and aquatic plants, but its chief source 

 of food is lichens. The long neck of the giraffe enables 

 it to crop the leaves of the local trees, which are picked one 

 by one with the help of its long flexible tongue. Goats will 

 eat almost anything, but when confined to their natural rocky 

 habitat they live on the scanty mountain herbage, which 

 consists largely of lichens. The food of sheep and oxen is too 

 well known to dwell upon, but the amount consumed in the 

 course of a year by a milking cow must be enormous. A 



Fig. 27. The Musk- Ox, Ovihos moschatus. 



first-class milker will produce in a year an amount of milk 

 which weighs fifteen times her own body weight. That cows 

 also eat the leaves of trees is shown by the fact that the 

 distance between the ground and the horizontal flat level of 

 the leafy part of trees is equal to the height a cow can raise 

 her mouth. The stomach, which is divided into four compart- 

 ments, is so arranged that the food which has found its way 

 into the first division (rumen) is sent up the oesophagus into 

 the mouth again, where it is solemnly chewed over and over 

 again. It is an interesting point to notice that during this 

 act, which is called rumination^ the lower jaw moves side- 



