VARIATIONS IN SIZE. 165 



casual observer of a collection of eggs, it is ap- 

 parent that this proportion is very far from being 

 the same in different families and species. Let us 

 take, for instance, the egg of the great auk. 

 This enormous egg measures four inches and ten 

 lines, or nearly five inches in length, and two 

 inches and three-quarters in breadth. This bird is 

 about the size of a fine goose. That of the golden 

 eagle, a much larger bird, is only three inches 

 long, and two inches and a half broad. The egg 

 of the Fulmar petrel, which is a small bird by the 

 side of the king of birds, is longer and larger 

 than that of the latter. The common guillemot 

 lays an egg which is a quarter of an inch 

 longer than the golden eagle's, though of a smaller 

 diameter. 



The ordinary egg of the guillemot varies re- 

 markably in size, and in its other characters ; but 

 it is always very large in proportion to the size of 

 the bird. Mr. Hewitson found one of an im- 

 mense size. It measured in length over the sur- 

 face of the egg five inches, and in circumference 

 seven inches and a quarter. The size of the 

 guillemot's egg is most striking when compared 

 with that of the other birds. Mr. Hewitson, in 



