Page:Popular Science Monthly Volume 92.djvu/289

 Why the Horse Is An Aristocrat

He is the product of an ancestry that goes back three million years

��THE earliest known ancestor of the horse, called the Eohippus or "Dawn Horse," is believed to have existed more than three million years ago, in what is known as the Eocene Age, hundreds of thousands of years be- fore the coming of man. Fossil remains of that animal were found in cer- t a i n rock strata in this x; o u n t r y. From the re- mains of a skeleton un- covered in New Mexico; J. W. Gidley, one of the sci- entists con- nected with the United States Na- tional Muse- um, in Wash- ington, D. C, reconstructed the interesting model which is pictured here.

This earliest known ancestor of the horse was about the size of a small fox, standing a little more than fourteen inches high at the shoulder. He had four toes on each of his front feet and three- toed hind feet. His teeth were small and short-crowned. He probably lived around the margins of lakes, where the ground was more or less soggy, and pastured on grass.

In the course of thousands of centuries, his physique developed as his needs re-

���Above appears the highest type of horse, the result of many centuries of careful breeding and selection. At his feet is shown his earliest ancestor, the Eohippus, who stood little more than fourteen inches high at the shoulder

��quired. His size increased and his skele- ton underwent important changes in accordance with his altered living condi- tions and habits.

The horse of the Oligocene period, known as Mesohippus, was about the

size of a sheep and had three toes on each "v foot. In the

Miocene, a little later period, there were numer- o u s large horses, all with three toes on each foot, but with the middle toe much larger than its companions. Their teeth were much longer, more powerful and much deeper- crowned.

In a still later period, called the Pliocene, were found the first horses with but a single toe on each foot, which soon developed into a hoof. The auxiliary toes, being useless, disappeared, and only the stumps remained, traces of which may be seen in modern horses, even those of the highest stock.

True horses, of the form and approxi- mate size of the modern steed, were not found until the Pleistocene period. These were common all over North America and Europe. Although they resembled the modern horse, they were smaller in size, and inferior in strength and fieetness.

��Those of us interested in science, engineering, invention, form a kind of guild. We should help one another. The editor of The POPULAR SCIENCE MONTHLY is willing to answer questions.

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