200 British Birds, 



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 oflf in 

 very large numbers and with every symptom of pre- 

 cipitation. But no ^<^g is ever dislodged ; a circum- 

 stance which some have sought to account for on the 

 supposition that they must bo cemented to the rock ! 

 The explanation really is, it would seem, that the 

 shape of the ^gg is such that, instead of rolling off in 

 any direction, as a ball would do on being sufficiently 

 moved, they 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 

 ^gg. 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 ^gg 

 is so large that but two illustrations can be given in 

 the limited space available to us. — Figs. 1, % plate X. 



BRUNNICH'S GUILLEMOT— (^r/^ Br'unnichii), 



Thick-billed Guillemot. — Easily distinguished by 

 an experienced eye from the last, but a bird of which, 

 perhaps, it can scarcely be said that it has been 

 actually ascertained to breed anywhere within the 

 limits of the British Isles. The egors 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. 



