THE OPEN SEA 85 
autumn that the young bird is able to leave the 
hole and fend for itself,—a very prolonged 
infancy which shows us that the nesting-place 
must be well hidden. In this connection it 
should be noted that the parents fly straight 
into the hole when they come in from the sea 
and leave in the same direct way. They are 
sometimes quite noisy as they fly about at 
night, but they know the safety of darkness. 
They come and they go in dim light, at dusk 
and at dawn. Most elusive birds! 
There is no doubt that the Storm Petrel 
belongs toa family of ancient birds, witha long 
pedigree going far back to some kinship with 
an extinct, giant, toothed Diver (Hesperornis 
of Cretaceous times). Like its relatives, such 
as the shearwaters, it has held its own by be- 
coming highly specialised in its everyday 
habitat and also in its way of feeding on small 
surface animals of the Open Sea. It is very 
interesting to find among its relatives a Diving 
Petrel (Pelecanoides), remarkably but decep- 
tively like a Little Auk, which has become a 
most expert diver, disappearing instantane- 
ously, swimming swiftly with its wings under 
water, and emerging again in flight—a bril- 
liant instance of the way in which survival is 
