Ages and ages after this, grass and trees began to ap-pear, and at last great forests covered the land, and over the fields and through the woods gigantic animals roved—strange and terrible-looking beasts, larger than any animal now living, and very fierce and strong. Among these were the mammoth and mastodon, which were so strong and ferocious that it would take hundreds of men to hunt and kill them. These great animals would go trampling through the forests, breaking down the trees and crushing the grass and flowers under their feet, or rush over the fields in pursuit of their prey, making such dreadful, threatening noises that all the other animals would flee before them, just as now the more timid animals flee from the lion or rhinoceros. Sometimes they would rush or be driven by men into swamps and marshes, where their great weight would sink them down so deep into the mud that they could not lift themselves out again, and then, they would die of starvation or be killed by the arrows of the men who were hunting them.