IN THE SHETLANDS 53 
and hereditary instinct that the shore is its place of 
safety, whatever the emergency may be, it there takes 
refuge.” The shag, as far as I know, has nothing 
particular to fear, either by sea or shore. His only 
enemy is man, who is not confined to either, but 
is as brutal and ignorant on the one as the other. 
But in avoiding danger the instinct of any animal 
would probably be to leave the place to which it was 
less accustomed, and run to that with which it was 
familiar—and this we constantly see. Thus a land- 
bird that was beginning to take to the water would 
leave it for the land on any alarm, whilst a water-bird 
under similar circumstances would make for the 
water. But all water-birds were probably land-birds 
once, so that we might expect sometimes to see in 
their young that old instinct of taking refuge there, 
which had become reversed in the parents. We 
might also expect to find greater dislike, on their 
part, to entering the water ; and certainly the young 
shags did enter it very unwillingly from the first. 
' So, indeed, for that matter did the old ones, as already 
stated, but with them there was the love of being 
on their nests, or at least their nesting-ledges—a late 
continuance of the breeding habits—to be overcome. 
When once they had plunged, however, they did 
not, like the young birds, swim at once to the shore 
again, but made for the open sea, and it must have 
required a strong contrary instinct on the part of the 
latter not to follow them. The lizards on the Gala- 
pagos Islands have, no doubt, also taken to the sea 
