486 ALCIDA 
vast bird-population takes ample advantage. This does not 
fall off at about 200 feet from the water, as at Horn Head, 
but covers the cliffs up to 500 feet. At this height the 
deeply-cut horizontal fissures are packed with a dense _ 
multitude of hatching Guillemots, which it requires careful 
scrutiny to inspect from the next cliff-top. These birds 
with Kittiwakes occupy also to its very apex that remark- 
able pinnacle which rises from an isolated base to some 
200 feet near O’Brien’s Castle. Its sides are all ledged in 
the lines of stratification, which are carried round the 
angles and, as it tapers, form lines of prominence round its 
shaft. It seems as if designed to hold the greatest possible 
display of bird hfe” (‘ Birds of Ireland,’ p. 362). 
The single egg, remarkably large for the size of the 
bird, is much elongated and pear-shaped. It varies in 
ground-colour as well as in other markings. Some examples 
are white, streaked and blotched with brownish-black ; 
others present a beautiful bluish-green tinge marked simi- 
larly and exhibiting zig-zag ink-like scrolls. Less frequently 
they are suffused with rich chestnut-red as seen in some 
of those of the Razorbill. Lastly, blue or white eggs, 
devoid of markings, are not uncommon varieties. Incuba- 
tion begins about the middle of May, and nestlings are 
seldom observed before the middle of June. During the 
process of hatching the shells generally become much soiled. 
About the middle of July the young reach the sea, being 
pushed off the cliffs by their parents. After the first week 
in August the breeding-haunts are quite deserted. I have 
not seen the offspring transported to the water in the hollow 
of the parent’s back, as has been stated by some observers. 
The young, on first reaching the water, remain on the 
surface crying like little Razorbills; soon, however, they 
learn to follow the old birds under the water. 
Geographical distribution—Abroad, the Guillemot breeds 
in the Faroes, Iceland, and over a large area of the coasts 
and islands of Northern Europe and the Arctic Ocean. In 
Temperate Europe it breeds in the Baltic Sea, on Heligo- 
land, on parts of the coast of France, and eggs have been 
obtained from the Berlengas Islands, off Portugal (Saunders). 
The breeding-range on the American Continent extends 
from Greenland, Northern Canada, and Alaska, down to 
California and New England; and on the Pacific side to 
Japan. In autumn and winter the Guillemot inhabits 
the North Atlantic Ocean down to lat. 30° N., and abounds 
