after a full meal, of sitting on some convenient perch with wings 
spread wide open and open-mouthed, apparently as an aid to 
digestion. But he is by no means so wedded to the sea as the 
shag. Rivers and inland waters will serve him as well as the sea. 
The gannet, though very nearly related to the cormorant, 
is a bird of very different habits and appearance. When adult 
it is snow white in plumage, with blue beak and feet, and can be 
mistaken for no other bird. Its peculiar mode of fishing was 
described in Chapter IT. 
Finally, there are two most interesting features of these birds 
which are worth remembering. To wit, the toes are all enclosed 
within one web, and they have no nostrils, and but the merest 
apology for a tongue. 
And now we come to the petrels. These are for the most 
part nocturnal birds, spending the day in burrows. They would, 
therefore, find no place in these pages but for the fact that one 
may occasionally be seen at sea when one is fishing off the shore in 
a boat. The commonest is that known as the Manx shearwater. 
Rather larger than a pigeon, it may be distinguished by its flight, 
which is rapid; the wings presenting periods of rapid quivering, 
alternating with long sailing with fixed, widely spread, narrow 
pinions. At one moment one sees only the deep black of the back, 
the next the pure white of the under parts as the birds turn now 
this way, now that, holding the outstretched wings at right angles 
103 
