316 CHARADRIIFORMES CHAP. 
when vast flocks arrive with great regularity, or even to an exact 
day. In England this occurs at the end of March or beginning 
of April, the latter part of August or the first week of Septem- 
ber being as punctually observed for departure. Except for 
purposes of procreation, or during violent storms, individuals are 
rarely seen on land, as might be expected from the clumsy 
style of gait; yet Puffins and Black Guillemots are fairly 
good walkers, and the former fly particularly straight and 
swiftly. Auks either splash along the surface of the waves 
before diving, or plunge suddenly, and when immersed use their 
wings much as if flying. The usual voice is a harsh-toned croak 
or grunt, but in addition Simorhynchus is said to chatter, Cyclo- 
rhynchus to whistle; Ptychorhamphus utters a musical ringing 
sound, the Little Auk a wild ery, and Black Guillemots a shrill, 
plaintive note. Fish, crustaceans, worms, and the like, with 
chance ship-refuse, compose the diet; the birds frequently dis- 
gorging it when scared, and sometimes in order to feed the young. 
The great pear-shaped egg of the Guillemots proper, and the 
more oval one of the Razorbill, is deposited on some bare ledge 
of a cliff, on a stack, or on an island rock. In the case of the latter 
bird the egg is usually in a crevice, being white or buff with 
black or brown markings, and generally, if not imvariably, green 
inside. Guillemots’ eggs vary from white or buff to brilliant 
green or blue, and are spotted, streaked, or covered with intricate 
wavy patterns of black, brown, or rufous; the same bird prob- 
ably always producing similar specimens. The Black Guillemots 
lay two greenish-white eggs with blotches of brown, rust- 
colour, and grey, under close-packed boulders or in holes low down 
in cliffs; that of the Little Auk is pale bluish-green, with or 
without faint rufous stains, and is found in similar, but commonly 
much higher, situations; Synthliborhamphus and various other 
forms use burrows in the turf, hke Petrels, as an alternative to 
chinks in rocks; but the first-named produces two buff eggs, spotted 
with brown and grey, while the remainder lay only one, which 
is either white, or very indistinctly marked. Of these, Puffins 
fashion a considerable nest of dry materials. In some instances 
at least, both sexes incubate, the period being nearly five weeks. 
When hatched in holes the young remain there for a considerable 
time, otherwise they are soon assisted by their parents to reach 
the sea. Where unmolested, Auks are sufficiently tame; Puftins, 
