“Exactly. One had four crests on the second molar, the other had three, but it was the three-crested type that had the first success and the three-crested style that led to the modern Mastodon. The first big Tertiary two-tusked Mastodon, who is called Dibelodon, had the three-crested tooth, and he spread everywhere. All the South American Mastodons were of his race. “Meantime, another of the family decided to develop the lower tusks, instead of the upper, and they stuck downwards at right angles to the lower jaw. If you can imagine an exaggerated walrus tusk effect, only coming from the lower jaw, instead of from the upper, you can get some idea of it.” “What a queer-looking brute! What would be the use of tusks like that?” “For roots,” his uncle replied. “It worked fairly well, for the family succeeded for a long time, too. The biggest specimen of Dinotherium, which was found in Roumania, was bigger than the largest Mastodon. But the Dinothere didn’t have the real emigration spirit. So far as we know, he never came to the New World. “At last came the true American Mastodon, developed from the three-crested tooth type. He lived during the Age of Man. Primitive Man hunted the Mastodon and the Mammoth, and has even left pictures of the chase engraved on reindeer horn. When you stop to consider the crude types of stone weapons that Man used at that time, it looks like long odds against the Man. Yet the Mastodons have all gone from the earth and Man remains.” “There were living Mastodons not so long ago, weren’t there, Uncle George?” “Quite recently,” the professor answered, “but the stories you hear about Mastodons having been seen within historic times are untrue. Still, their skeletons are never deeply buried. They are generally found in bogs and swamps. A great many have been found in New York State and their fossil remains are plentiful all over the Middle West. You know that big swamp about twenty miles south of here?” “You mean Jackson’s Bog?” “Yes.” “Sure. I’ve often gone after wild duck, there.” “I wouldn’t be at all surprised if there were Mastodons in that swamp. I don’t mean for shooting purposes,” and the professor laughed, “but buried there. Some of these days, if the swamp is drained, possibly many Mastodon skulls and tusks will be found. The animals swarmed all over this part of America. One skeleton, even, which was found in New York State, was so well preserved that masses of golden-brown hair were found still attached to the withered skin.” [Illustration: _Courtesy of American Museum of Natural History._ THE AMERICAN MASTODON. The ancestor of the modern elephants; note the extreme heaviness of body and the sloping head. The mastodon was heavier than the modern elephant, though not as tall.] [Illustration: _Courtesy of American Museum of Natural History._ THE SIBERIAN MAMMOTH.