36 THE BOOK OF NATURE STUDY 



and fifth are now reduced to vestiges. In other respects the 

 limbs agree with those of the horse. 



The teeth of the horse demand special mention. As in 

 the case of the rodents rabbit and mouse there is a great 

 toothless gap between the incisor or cutting teeth in the front 

 of the jaws, and the " cheek" teeth, or grinders; though small, 

 and now useless " canine" or "eye" teeth, are met with in some 

 horses and deer. Horses use their lips in feeding, grasping the 

 grass therewith, and thrusting it between the teeth. The jaws 

 closing tightly on the intended mouthful, the stalks are torn 

 from their roots by a jerk of the head, and passed on to the 

 grinders and reduced to fragments. And herein horses differ 

 conspicuously from cattle, deer and antelopes. In these animals 

 there are no cutting teeth in the upper jaw, their place being 

 taken by a soft pad ; but, as in the horse, there is a gap between 

 the cutting teeth and the grinders. But instead of the lips the 

 tongue is used to draw the food into the mouth, and to enable 

 it to do this the more effectually its surface is covered with rough 

 points, all directed towards the throat, just as is the tongue 

 of the lion and the cat. 



Oxen, deer and antelopes are, as is well known, peculiar 

 in that they " chew the cud," or " ruminate." Thereby they 

 are enabled to rapidly devour a large quantity of food and then 

 retire into some retreat secure from enemies, such as lions or 

 tigers, for example, and quietly digest it. This work of 

 digestion is rather a complex process ; and, to effect this, the 

 stomach has become divided into a number of separate compart- 

 ments four, to be quite precise (Fig. 10). As the food is swallowed 

 it passes into the first portion of the stomach, the " rumen " 

 or " paunch," where it undergoes a softening process ; this com- 

 pleted, it is brought up again, bit by bit, into the mouth with 

 a kind of " hiccough," and there chewed in the slow and deliber- 

 ate manner so familiar to those who have watched cows and 

 sheep when lying down in the shade after browsing. As each 

 mouthful is reduced to pulp there is a pause, when, if the animal 

 be carefully watched, this mouthful will be seen to pass down 

 the gullet to the stomach, to be succeeded immediately by a 

 second bolus. Each bolus is prepared by passing the food from 



