340 THE BIRD WATCHER 
fore limb of the foggmer, we may perhaps surmise, 
was of so small a size that, even after it had become 
fin-like, only those variations in the direction of 
smallness were of benefit to it, whereas, for a contrary 
reason, the reverse was the case with the other— 
though I should think this far more likely if the true 
seals, like the beaver and otter, had a large and well- 
developed tail. As they have none, I rather suppose 
that their fore-feet were, for some period, enlarged 
and broadened out, and only ceased to be so owing 
to the gradual tail-like development of the hind feet 
and posterior part of the body. This, the evolved 
tail, began then to play the chief part in natation, as 
it does in fishes, and, for similar reasons, I believe that 
the otariide are advancing along the same lines, and 
that their mode of progression in the water will, one 
day, be more truly seal-like—that is to say, fish-like— 
than it is at present. 
But let the ancestry and process of modification, 
as between the two families, have been as different 
as we can, with any likelihood, suppose it to have 
been, yet still it is not quite easy to understand why 
one marine animal should, whilst retaining the power 
of quadrupedal progression, possess also greater 
aquatic powers than another one, which, travelling by 
the same evolutionary road, has gone farther on it, 
has lost the terrestrial gait, become less a quadruped, 
and approached considerably nearer to the true aquatic, 
or fish, type. Should not the fish form excel all other 
forms in the water ? and, if so, should not the quad- 
