The nostrils and the ears of the seal are made in such a way that water cannot enter them when the animal is diving. They are furnished with little valves, which are so arranged that they close as soon as the water presses upon them. And the greater the pressure the more tightly they shut up, so that not the tiniest drop of water can ever enter them.
There is still one more way in which the animal is specially fitted for its life in the water. It has to feed on fishes, and fishes are very slippery creatures. If you have ever tried to hold a live fish in your hand you will know that it is a difficult thing to do, for the fish just gives a wriggle and a twist, and slips out of your grasp as if it had been oiled. So that it would seem quite impossible for the seal to hold its finny victims, even if it overtook and seized them. But when we come to look at its teeth we find that those which we call molars, or grinders, are set with long, sharp points; so that when a fish is seized they enter its body, and hold it in a grip from which there is no escape.
The Common Seal
There are many different kinds of seals, but we shall only be able to tell you about four or five of the best known.
The first of these is the common seal. It is found on both sides of the Atlantic Ocean and in the North Pacific. On some coasts it is much disliked by fishermen, owing to the great number of fishes which it devours. It is so cunning that it will even find its way in among the nets they have let down, feast heartily upon the captive fish, and then quietly swim out again, often doing the same thing day after day for weeks together. And it is almost impossible to destroy it, for it seems to know perfectly well when its enemies are on the watch, and will only expose its nostrils above the water when it comes up to the surface to breathe.
Very often fishermen consider it "unlucky" to kill a seal, so that the animal is able to carry on its robberies without being interfered with.
The common seal, when fully grown, is about five feet long, and is yellowish gray in color, with a number of darker spots sprinkled over the body and sides. It is very active in the sea, and fairly active on land, for although it cannot walk it will shuffle along over the beach at a wonderful pace for such an animal. As it does so, it throws up a perfect shower of stones with its hinder nippers, and those who have chased it have often thought that it was doing so on purpose, and was actually throwing stones at them.
If this seal is caught when quite young and treated kindly, it soon becomes exceedingly tame. It has even been known to live indoors, like a dog or a cat, and to lie for hours together basking in front of the fire. And in more than one case, when its owner wished to get rid of it, and put it back into the sea, it swam after him, crying so pitifully as he rowed away that he could not bear to leave it, and took it home with him again after all.
Sea-Lions
The sea-lions are so called because they are supposed to look very much like lions. But it is not easy to see the resemblance. Sometimes they are called hair-seals, because there is no soft woolly under-fur beneath the coating of thick bristles, as there is in most of the animals belonging to this family.