IN THE SHETLANDS 337 
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 
1 It is stated, however, in The Watcher of the Trails, that an otter can actually 
outswim a large and powerful trout. 
Z 
