It is strange that while every child knows something about seals, very few people have heard of these gentle grazing manatees and dugongs, the only large vegetable-feeders of the sea. Yet they are curious, interesting animals, and seem to be the forms which have given rise to the popular stories of mermaids,[185] for they suckle their young ones at the breast, clasping them with their flippers, and when they raise their heads in the water have something the appearance of an uncouth mother nursing her child.

Fig. 83.

The Manatee or Sea Cow grazing.

But very uncouth indeed! for they are long barrel-shaped creatures, with a thick skin like the elephant’s, with short stiff hairs upon it. Their head is small, with no outer ears, and very insignificant eyes surrounded with wrinkles; their lips are thick, heavy, and covered with short bristles, and above them two narrow nostrils open and close according as they are above or under water. Their front flippers, which are all they have, are long and broad, with faintly-marked flat nails upon them, and behind these their body tapers away gradually into a thin, wide, shovel-shaped tail, not set edgewise as in a fish, but across the body, so as to lie like a broad leaf in the water.

Who would think that a creature like this had anything in common with land animals? Yet so it is, for not only do we know that his ancestors had traces of hind legs, but his front limbs are quite as true arms and hands as those of any of the seals. Moreover, he has large broad grinding back teeth like the elephant, and in front he has small cutting teeth as a baby, though these are covered up by the gum as he grows older. In the Australian dugong, however, these teeth continue to grow and form good-sized tusks in the fathers.

What, then, is this curious animal? Simply a vegetable-feeder which has become fitted for a watery life—a gentle, peaceable animal, which keeps near the shore and grasps the seaweed with the sides of its upper lip, and then nips it off by a set of horny plates, which grow down from the roof of its mouth, and answer to the rough wrinkles on a cow’s palate. They may often be seen together, father, mother, and child, wandering up the river Congo in Africa, or the Amazons in South America, feeding entirely under water, and only raising their heads from time to time with a snort to take in fresh air. In olden times they probably thronged all the coasts on the sea-margin, for a hundred and fifty years ago there was another group of them, the Rhytinas, right up in the cold seas of Behring’s Straits, where the vast submarine forests of seaweed afforded them plenty of food. But the sailors found them such good eating, and the fatty blubber on their bodies was so valuable, that they were all killed twenty-five years after Behring first discovered them, and unless some care is taken, the more southern sea-cows may some day be exterminated in the same way.

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And now that we have firmly grasped the fact that the seals and manatees, however altered in shape, belong to the four-footed and milk-giving group, perhaps we shall be prepared to understand how it is that the whales[186] are not fish, though this popular delusion is one of the most difficult to overcome. “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 fish 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 (see [Fig. 84]); its tail is a piece of cartilage or gristle, 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 (see [Fig. 85]). Nay! the whalebone whales have even the traces of hind legs entirely buried under the skin (see [Fig. 84]), 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.