IN THE SHETLANDS 379 
and the seal-rocks which I passed in the steamer were 
such as to support this view. 
Putting everything together, I believe that, both 
in respect to the rocks on which they lie, and the 
times at which they lie on them, the one and only 
law by which seals are governed is the law of prac- 
ticability. It is a very good law, and I wish I had 
always been governed by it too—I mean beforehand. 
