this they pull and tweak. In spite, therefore, of the peculiar wedge-like bill with its obtuse tip that seems so well adapted for striking a limpet or other shell-fish with a sudden blow from the rock to which it had been clinging, I am beginning to doubt whether they often use it in this way, and especially whether limpets are a special food of theirs. I remember, however, once seeing a sea-pie make just the sort of blow required on the theory, but ineffectively, and in a peculiar half-hearted way, as a man might feebly clench his fist and strike in his sleep. It is curious that this trivial action, which seemed to be of an involuntary nature, made under a misapprehension discovered in time to check, but not to stop, the blow, has remained in my memory with a strange persistence and vividness, and on the strength of it I still think that limpets are sometimes struck from the rock in this way. There must, I think, have been something very specialised in the movement of the head and bill, slight as it was, to make me retain it so long in my mind's eye.
Afterwards I watched several of these birds feeding on the rocks, and I distinctly saw one with his beak amongst a bed of the same small blue mussels that I have seen the eider-ducks feeding on, picking and pulling at them in much the same way. Others, like the first one, pulled at the brown, or black, seaweed with which the rocks are plentifully hung. They ran down upon it when the sea receded, and back, or else jumped into the air or flew to another rock, when it
