EGGS OF BRITISH BIRDS. 93 



can lay its eggs ; ledges are shunned. The Eazor-bill must have 

 a hole, if one can possibly be obtained. The eggs are deposited 

 on the cliffs at various heights from the water, but seldom very 

 close to the sea, and generally near the summit. 



The eggs of the Razor-bill vary very much, but the range of 

 variation, both in the colour and shape of the spots, is not nearly 

 so great as in those of the Guillemot. A remarkable difference 

 between the eggs of these two birds is to be found in the fact that 

 whereas those of the latter species, when viewed through the 

 hole against the light, sometimes appear cream-coloured and 

 sometimes green, the eggs of the Razor-bill, when examined in 

 the same way, always look green, though on the surface they 

 never show more than the faintest tint of that colour. The 

 ground-colour of the eggs of the Razor-bill varies from pure white 

 to pale reddish-brown. The colour of the overlying spots is dark 

 reddish-brown, sometimes approaching black, and that of the 

 underlying spots pale greyish-brown ; they vary in size from large 

 blotches, often confluent round the large end, to the minutest 

 speck. In rare instances a few streaks are mixed with the spots, 

 and in still rarer instances most of the markings are streaks. 

 The normal eggs vary in length from 31 to 2*7 inches, and in 

 breadth from 2*25 to 2'2 inches. 



THE COMMON GUILLEMOT. 



(Alca troile.)* 

 Plate 25, Figs. 1 — 6. 



The Guillemot breeds in all suitable localities from the Isle of 

 Wight in the south, up to the north of Scotland, as well as in the 

 islands off the coasts. It nests also in Western Europe from the 

 coasts of Portugal and France to Heligoland and the Baltic and 

 along the coasts of Norway. It also breeds in North America 

 from New England to lat. 64 o N. 



The Guillemot lays but a single egg, on the bare rock. The 



variation in the colour and marks of the eggs is so pronounced 



that no description can convey an adequate idea of them, and I 



have figured a few of the most remarkable forms. They vary in 



* Uria troile — Saunders, Manual, p. 683. 



