Page:Popular Science Monthly Volume 22.djvu/771

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PROGRESS OF THE BACKBONED FAMILY.

splints that the horse still reveals to us that he belongs to the three toed animals.

A far different race from the Herbivora is the large army of flesh feeders, which we find throughout all past ages harassing and destroying the vegetable-feeders on all sides. And yet it would not be fair to speak of these larger flesh-feeding animals as if they had worked nothing but evil to their more peaceful neighbors, for how would Life educate her children if she put no difficulties in their way to be conquered, no sufferings to be endured? It was in the long struggle for life that the animals with the largest and strongest horns got the upper hand, that the swiftest horses or antelopes survived and left young ones; while we must remember that it is more often the sickly, worn out, and diseased animals that fall a prey to the devourers, and their life is ended far less painfully than if they dragged themselves into some hole to die.

"On revient toujours à ses premiers amours" says the French song. But who would have thought that, after rising step by step above the fish, and tracing the history of the backboned animals through their development in the air and over the land till we brought them to a state of intelligence second only to man, we should have to follow them back again to the water and find the highly-gifted milk-givers taking on the form and appearance of fishes? Nevertheless it is so, for seals and whales are as truly flesh-eating milk-givers as bears and wolves. "Do you really mean, then," exclaim nearly all people who are not naturalists, "that a whale is not a huge fish?" Certainly I do! A whale is no more a fish than crocodiles, penguins, or seals, are fishes, although they too live chiefly in the water.

A whale is a warm-blooded, air-breathing, milk-giving animal. Its fins are hands with finger-bones, having a large number of joints; its tail is a piece of cartilage, and not a fish's fin with bones and rays; it has teeth in its gums, even if it never cuts them; and it gives suck to its little one just as much as a cow does to her calf. Nay, the whalebone whales have even the traces of hind legs entirely buried under the skin, and in the Greenland whale the hip-joint and knee-joint can be distinguished with some of their muscles, though the bones are quite hidden and useless.

There was once a time when the great army of milk-givers had its difficulties and failures as well as all the other groups, only these came upon them not from other animals, but from the influence of snow and ice.

For we know that, from the time of tropical Europe, a change was creeping, during long ages, over the whole northern hemisphere. The climate grew colder and colder, the tropical plants and animals were driven back or died away, glaciers grew larger, and snow deeper and more lasting, till large sheets of ice covered Northern Europe, and in America the whole of the country as far south as New York.