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IN THE SHETLANDS 219 
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. 1 remember, however, 
once seeing a sea-pie make just the sort of blow re- 
quired 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 
