198 TYPES OF ANIMAL LIFE 



from it on one side, at a certain point, an enlargement 

 called a "caecum." Now, all the odd-toed ungulates 

 have a stomach, which is simple in shape, as is the 

 human stomach, but they have an enormous and com- 

 plexly formed crecum. All the even- toed ungulates, 

 however, wdiether ruminating or non-ruminating, have, 

 on the contrary, a complex stomach and a simple caecum. 

 The most complex stomach is that of the deer and 

 hollow-horned ruminants, each of which is provided with 

 four cavities. The freshly cropped food passes dow^n into 

 the first cavity or paunch, whence it goes to the second 

 compartment called, from the character of its lining, the 

 honeycomb bag. Thence it passes upward to the mouth 

 to be chewed once more, whence it descends again to the 

 mr.nyplies, so named from the many folds of membrane 

 witJiin it ; and then, last of all, goes to the true digestive 

 chamber of the stomach, called the reed, which opens into 

 tho intestine. 



Three further points may be noticed, which though in 

 themselves small, yet serve to distinguish the two great 

 groups of ungulates from each other. There is a certain 

 bone of the skull of man and beasts known as the wing- 

 wedge bone, which bone may have a perforation or canal 

 through which a branch of the carotid artery passes. 

 The odd-toed ungulates have this, but the even-toed 

 have it not. The bone of the thigh of man and beasts 

 possesses two bony prominences, or trochanters. The 

 even-toed ungulates like ourselves have these two and 

 no more, but the odd-toed ungulates also possess a third 

 trochanter. The number of bones of the back, together 

 with those of the loins, are seventeen in man. In ungu- 

 lates they are never less than nineteen, and may be 

 more, as in the horse, where they are twenty-four in 

 number. 



