in the Plate annexed. Both birds take their turn in hatching the egg, 

 incubation lasting from twenty-six to thirty days. 



There is not nearly such a diversity of colouring among the eggs of the 

 Razorbill as is to be found among those of the Guillemot, though there arc 

 many types and varieties of Razorbill's eggs. One remarkable difference is 

 noticeable after they are blown : whereas those of the Guillemot when held up 

 to the light look sometimes cream-coloured and sometimes green, through the 

 hole the Razorbill's egg always looks green, although there be not the faintest 

 trace of that colour on the surface. In ground-colour the Razorbill's eggs 

 vary from white to pale reddish brown, sometimes with a very faint greenish 

 tinge, but this is rare, and usually soon fades, leaving the shell pure white. 

 The surface-markings are rich dark reddish brown, sometimes nearly black, 

 and sometimes there are a few rich light chestnut marks. Underlying markings 

 are pale grey or greyish brown, and have the same character as the surface 

 marks, varying from huge blotches, which are usually on the large end of 

 the egg, to very small specks. They vary in length from 3-20 to 375 inches, 

 and in breadth from 2'O to 172 inch. 



Young in down are brownish black on the upper parts, and have greyish 

 white under parts and a greyish forehead and throat. 



