622 



X. IT URAL HISTORY. 



but in 



In the 



the past 

 one the 



y\ 



such forms lived, and from them two lines have diverged, 

 number of toes are even (two or four) , while in the other 

 they number one or three. This difference corresponds to 

 two great divisions of the ungulates, and has been brought 

 about by the degeneration of one or more of the toes. For 

 instance, in the horse there is but one toe remaining in the 

 functional foot (the middle one), but farther up we find on 

 the side of the ' pastern bone ' two small bones known as 

 the ' splint bones,' which are respectively the second and 

 fourth toes of the five-toed ancestor in a very rudimentary 

 condition ; and in rare abnormal cases a reversion to an 

 older type may be seen, and one or both of these splint 

 bones may bear hoofs. In the series with the toes two or 

 four in number, the first toe is lost first, as in the case of 

 the pig, and then the second and fifth go, as is seen in the 

 great majority of the group. The various stages in this 

 process are extremely interesting, but cannot be detailed 

 here. We can only say that the odd-toed forms are re- 

 garded as lower than those in which the toes are even hi 

 number, and hence are to be considered first. 



Fig. 493. — Skeleton 

 »>f the foot of a 

 horse. The mid- 

 dle toe (3) of the 

 typical vertebrate 

 foot alone reaches 

 the ground; two 

 other toes (the 

 second and fifth) 

 remain as the 

 splint bones (,S) ; 

 the others have 

 disappeared. 



In the tapirs we meet a peculiar foot structure, which at 

 once indicates their position at the base of the series. They 

 have four toes on the fore feet and three on the hinder ones; 

 a fact which taken by itself would render it difficult to say 

 in which of the two groups of ungulates these forms should 

 be placed. Fortunately there are other characters which 

 decide the question. All of the tapirs with one exception 

 inhabit Central and South America ; the exception is found in the East 

 Indies. They are rather stupid animals with nocturnal habits, living in 

 the dense forests and eating all sorts of tender and succulent vegetable 

 matter. Their flesh is good for food, and their hide makes good leather, 

 and for these reasons they are hunted extensively. The most remarkable 

 feature about them is the long nose (much longer in some than in the 

 species figured), which is capable of considerable extension, and which can 

 be used in much the same way as the trunk of the elephant. 



There are six species of rhinoceros to be found in the tropical parts of 

 the Old World. They are large and clumsy thick-skinned animals charac- 

 terized among other things by the possession of one or two horns upon the 

 snout. The one-horned forms arc found only in the East Indies, while 

 those with two of these nasal appendages are found in both Asia and 



