IN THE SHETLANDS 109 
ledge, often uncomfortably near to the edge of it, and 
at last gets round a corner, out of my sight. The 
parents, as far as I can make out, have not followed it. 
This is quite a new development in my experience of 
the chick, if not in the chick’s own experience. It is 
not, then, quite immovable, till it flies or is carried 
down. Were it to fall now, how aptly would it illus- 
trate that law of natural selection which I have called 
in to account for its general quiescence. I hope it 
won't though—which is to my credit surely. 
I note one more thing before leaving. A bird 
picks up and, as it were, plays with some feathers 
lying on the ledge, one of which it now brings to its 
partner, lays it on the rock, and then both pull it 
about. This, too, I noticed when I was last here. 
I have mentioned it in my Bird Watching, and account 
for it by supposing that we here see a last trace of 
the once active nest-building instinct. Perhaps, how- 
ever, the act is too trivial to need any special account- 
ing for. 
