194 TYPES OF ANIMAL LIFE 



the same fundamental plan as is the hind foot. Each of 

 the four fingers is supported by three bones, attached 

 end to end, while the thumb, like the great toe, has but 

 two. These five series of finger-bones are each respect- 

 ively attached to the end of one of five longer and 

 stronger bones which lie along the middle of the hand, 

 and so may be called middle-hand bones. They are 

 attached by their other ends to a group of short bones, 

 which are the wrist bones. Now, very many beasts, like 

 the bear, agree with man in walking with the entire sole, 

 or plant, of the foot directly applied to the ground, and 

 such are, therefore, called plantigrade. Others, like dogs 

 and cats, walk on their toes only, and keep the soles of 

 the feet and the parts which answer to the palms of our 

 hands raised up from the ground. Such animals are 

 called digitigrade, because they walk on their digits, which 

 is a common term used to denote equally both fingers 

 and toes. Now, no ungulates place the plant of the foot 

 on the ground, while almost all of them do not rest even 

 on their toes, but only on the very tips of their toes, for 

 they walk on their hoofs — that is to say, on the great 

 nails which encase the terminal bone of each finger and 

 toe, or, in other words, the terminal bone of each digit. 

 It is only in the camels and llamas, which are digitigi'ade 

 and which have coarse nails instead of true hoofs. No 

 ungulate has either a thumb or a great toe, while the 

 number of digits may be reduced to one for each limb. 



In the odd-toed ungulates the bones of the foot are 

 developed symmetrically on either side of an imaginary 

 axis passing down the middle of that digit which cor- 

 responds to our middle finger and middle toe. Such is the 

 case even with the tapir, which has four toes to each hind 

 foot, though the outermost is not reckoned a functional 

 one, the animal resting on but three. The rhinoceroses 



