106 BRITISH BIRDS, THEIR EGGS AND NESTS. 



impossible out of a collection of many scores to pick out half a 

 dozen that are precisely alike, either in ground-colour or general 

 markings. The eggs are laid on the ledges of rocky precipices 

 overhanging the sea, on various parts of the British coasts. I 

 have frequently seen the Willocks under the impulse of a sudden 

 alarm for instance, the firing of a gun in the close vicinity of 

 their egg-bestrown ledges fly off in very large numbers and 

 with every symptom of precipitation. But no egg is ever dis- 

 lodged ; a circumstance which some nave sought to account for 

 on the supposition that they must be cemented to the rock ! 

 The explanation really is, it would seem, that the shape of the 

 eggs is such that, instead of rolling off ir any direction, as a 

 baU would do on being sufficiently moved, tney simply turn round 

 and round within the length of their own axis. It would serve 

 but little purpose to attempt a description of the Guillemot's 

 egg. They are of all shades, from nearly or quite white to a 

 dark green, some profusely spotted and blotched and streaked 

 with dark colours, others very slightly so or scarcely at all. 

 Unfortunately the egg is so large that but two illustrations can be 

 given in the limited space available to us. Fig. 1, 2, plate X. 



280. BKUNNICH'S GUILLEMOT (Una Bmnnichii). 

 Thick-billed Guillemot. Easily distinguished by an expe- 

 rienced eye from the last, but a bird of which, perhaps, it can 

 scarcely be said that it has been actually ascertained to breed 

 any where within the limits of the British Isles. The eggs are 

 described as varying from those of the Common Guillemot in 

 their greater roundness ; they are less long in proportion to their 

 thickness than the others, but seem to run through the same 

 endless variations of ground-colour. 



281. RINGED GUILLEMOT (Una lacrymans). 

 Bridled Guillemot. There has been some doubt whether this 

 bird is to be considered a distinct species, or merely a variety 

 of the Common Guillemot. It is now, however, generally ad- 

 mitted as a good species. It occurs in company with the other 

 Guillemot on various parts of our coasts, and in Wales is said 

 to be equally numerous with it. The eggs are distinguishable 

 from those of the other two species already named, but still ex- 

 hibiting precisely similar characteristics. 



282. BLACK GUILLEMOT (Una GryUe]. 

 Tyste, Scraber, Greenland Dove, Sea Turtle. Sensibly less 

 in size than the Common Guillemot, and not found commonly 

 on our more southerly coasts. Shetland, the Orkneys and 

 Western Isles are all frequented by them, and their quick 

 ind lively motions are pleasant enough to witness. These birds 



