Nests and Eggs 165 



although we know from their general anatomy that they 

 are all members of one great Order. Of the remaining 

 Orders of Birds, it may be said that the eggs are for the 

 most part characteristic, and that those of Grebes, Divers, 

 Penguins, Petrels and Gulls are easily recognizable. Those 

 or Pigeons and Rails are also highly characterized, but 

 among the Game-birds there is considerable variation, 

 some laying white or buff-coloured eggs with scarcely any 

 markings, while in the Quails the eggs are much scribbled 

 over and lined with black. 



No egg varies more in colour than that of the Common 

 Guillemot ( Uria troile), which laj-s its single pear-shaped egg 

 on the ledge of a rock. Scarcely two Guillemot's eggs 

 are exactly alike, and the difference in the type of colour 

 and markings is truly remarkable. Thus the ground-colour 

 varies from white to creamj'-buff, bluish or green, or even 

 rufous-buff, while the spots and blotches are either 

 evanescent, or may almost cover the shell, so that it is 

 impossible to give an exact diagnosis of the (fg^g of the 

 Guillemot. Tinamous likewise lay a wonderful egg, not 

 only as regards colour, which may be apple-green, or 

 purple, or grey, but on account of the extraordinary 

 varnish or gloss which distinguishes their eggs from those 

 of all other birds, and renders them quite unmistakable. 



In reviewing the peculiarities of nests and eggs 

 enumerated in the foregoing summary of the Class Aves, 

 it is necessary to note that many birds make no nests at 

 all, and that these belong to many different Families, so 

 that, although the Picarian Birds and Woodpeckers lay 

 their eggs in concealment, there are other birds, like the 

 Guillemots and Razorbills, which lay their eggs in the 

 open, but yet make no attempt at a nest. The Auks 

 have already been alluded to as a remarkable family of 

 Birds, and they may be said to play, in the Arctic Regions, 

 the role which the Penguins carry out in Antarctic waters. 



