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THE POPULAR SCIENCE MONTHLY. 



nourish such bulky bodies ; and, the third, good defensive weapons 

 to protect themselves against each other and against their enemies. 



4LfeSfeft*j& 



Fig. 9. 



In the three-toed group of the vegetable-eaters, the horse has the 

 most interesting history. It was in America that the tribe began, for 

 there we find that tiny pony not bigger than a fox, with four horn- 

 covered toes to his front feet (and traces of a fifth), and three toes on 

 his hind ones. Then, as ages went on, we meet with forms with only 

 three toes on all the feet, and a splint in the place of the fourth on 

 the front ones. In the next period they have traveled into Europe, 

 and we find larger animals with only three toes of about equal size. 

 One more step, and we find the middle toe large and long, and cov- 

 ered with a strong hoof, while the two small ones are lifted off the 

 ground. Lastly, in the next forms, the two side-toes became mere 

 splints ; and, soon after, well-built animals with true horse's hoofs 

 abounded, the one large hoof covering the strong and broad middle 

 toe. For what we call a horse's knee is really his wrist, and just be- 

 low it we can still find under the skin those two small splints running 

 down the bone of the hand, while the long middle finger, or toe, with 

 its three joints, forms what we call the foot. It is by these small 



