Page:BirdWatcherShetlands.djvu/371

Rh to go eight or nine times their own length in the same time that seals or penguins take to double theirs, only. In the case of the otter, however, there is often no such great discrepancy in size, and here we must suppose the victory of the mammal to be due to its superior intelligence, or its power—as, perhaps, a result of it—of taking the fish by surprise. But it is not only in such cases as the above, that this curious law of the superiority of the apparently less fit may be made out, or imagined. It obtains also amongst animals differing but slightly from one another, and whose habits are identical, or nearly so. Look, for instance, at the seals themselves. The common one of our northern coasts has much more lost the typical mammalian form, and become much more like a fish, to look at, than several species that are moving in the same direction, amongst them the fur-bearing seal that is skinned alive to keep ladies here warm, whilst the Japanese in Manchuria wear sheep-skins. In these, all four limbs are still used for their original purpose of terrestrial locomotion, so that instead of jerking themselves painfully forward on their bellies, as the common seal and others have to do, they go upright, and even fairly fast, though with a peculiar swing and shuffle. Inasmuch, therefore, as they have become far less unfitted for the land, one might imagine that they would be less fitted for the water, and that the common seal, from having been