Page:BirdWatcherShetlands.djvu/373

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IN THE SHETLANDS
339

coasts—were relegated to one that, though an ordinary man might find it rather large for such a purpose, would be of a convenient size enough for Chang, or some other giant, to wash his hands in. In neither, naturally, could a pinnipede do himself justice, and perhaps these ones felt it more than the other kind. Now, however, I have seen them far more active in their native ocean, yet they fell short of those others, in captivity, to a degree which makes me think they would never be able to compete with them.

It may be thought that the larger size of the sea-bear's, or sea-lion's flippers, and the greater use which they make of the anterior pair, simply and easily explains their greater speed in the water. But why, then, should the true seals—the phocidæ, which must once have been in the same sort of transition stage between ordinary walking and their own gait, that the otariidæ are now—why should they have passed forward into their present more fish-like condition, since both the advantage of walking has been thereby lost, and that of swift swimming seems to have been lessened? Of two creatures, each of whom has, from once being a land-animal, become a water-animal, why should the one whose structure has been least modified in relation to the change, be more active in the water than the other? The phocidæ and otariidæ, it is true, though belonging to the same sub-order, may be the descendants of species that differed considerably from one another, and thus they may have undergone a different course of modification. The