“Any one, trained or untrained, can find fossils,” the scientist reminded him. “I tell you, Perry, there’s not a corner of the United States from which a fellow couldn’t drive to a fossil-bearing locality, and not many places where a fellow couldn’t reach fossils in a day’s walk.” “You mean big beasts like the giant reptiles?” “Not only those, of course. No. I’m speaking about fossils of all ages. For example, the Fort Lee Reptile was of the Triassic Period, Perry, so you see he belongs to a long time ago. “In some places, the rock deposits are marine, and one might find fossil fishes. Some rocks were deposited near great forests and one might only find fossil leaves and ferns, with, perhaps, primitive insects something like dragon-flies, called _Meganeura_, a foot and a half long. In many places the rocks hold sea creatures from five to fifteen million years old. If every youngster in the United States would look around for fossils when he got the chance, we’d probably find more new species in a year than we find now in ten years. “I wish I had the opportunity that school-teachers have in country schools! There isn’t a little red schoolhouse in all the country that couldn’t have a splendid local museum, if only the boys would get together.” “I’ll get a gang together just as soon as I get back,” cried Perry. “Do that,” said the professor, “tramp the banks of streams and railroad cuttings, everywhere that the soil has been cut away. First thing you know, you’ll drop on some rare prize that science might never have heard of otherwise.” “All right, Uncle George,” said the lad, “I’ll remember that and I’ll see if I can’t get a Mastodon for our little museum out of Jackson’s Swamp. How about a Mammoth? Could I get one there, too?” “Not so likely,” was the scientist’s answer. “The Mammoth only came south with the ice sheet. He was distinctly a winter-loving beast. That’s why we have better fossils of the Mammoth than of any creature. Explorers have found him mummied and almost whole, the entire carcass frozen stiff and preserved with the hide and flesh. Two complete specimens were found in Siberia and only a few years ago (1908) one of our museum men secured the larger part of a carcass, with hide and hair, from the edge of the frozen tundra in Alaska.” “What’s the difference between Mammoths and Mastodons?” “Teeth,” was the succinct reply. “The Mastodons had chopping teeth, the Mammoths had grinding teeth. You can tell them apart at once. The tusks of the Mastodon were more often straight, those of the Mammoth frequently curved inward.” “Which was the bigger?” “The biggest of the Mastodons was heavier than the biggest of the Mammoths, but more stockily built. The Mammoth was taller. The most imposing of them all was the Imperial Mammoth of North America, thirteen feet six inches at the shoulder, with huge incurving tusks. But if it came to fighting, I would place my faith on the American Mastodon.”