CRITICAL NOTICES OF NEW PUBLICATIONS. 125 



or the ducklings, or breaking an egg ; neither would it touch nuts, 

 nor anything else we offered, though in the wild state, we are told, 

 it subsists partly on insect food. We trust the above will sufficient- 

 ly clear its character from the aspersions which gave rise to our di- 

 gression. " There is a peculiarity," Mr. Hewitson justly observes, 

 '^ in the eggs of the Grebes which immediately distinguishes them 

 from those of all other birds ; they are widest in the middle, and 

 taper so regularly towards each end that it is not easy to distinguish 

 that which is, in other eggs, the broadest. They are rarely seen of 

 their natural and original purity ; when first laid they are of a 

 spotless chalky white, sometimes slightly tinted with blue, but by 

 coming in contact with the materials of the nest, by which they are 

 also covered on the departure of the bird, they soon assume a very 

 different aspect, and become besmeared and thoroughly stained 

 through with various shades of dirty green." To this we may ap- 

 pend that they present an absorbent, unenamelled surface, which 

 imbibes the discoloured moisture of the nest materials in a way 

 which few other eggs would do. The Cormorant's and Puffin's 

 eggs are the few we allude to, but even these are not exactly as 

 those of the Grebes. There may be a reason, possibly, for these 

 shells absorbing moisture. The eggs of the Crested species may be 

 always easily obtained in the season in the London markets. 



A large dark brown egg, sparingly spotted with deeper black- 

 ish brown ; that of the great Northern Diver. A specimen 

 in the national collection, agreeing in size, is of a dull white, with 

 a few small, scattered, irregular spots, of the hue of the ground-co- 

 lour of Mr. Hewitson's figure ; besides which some larger spots also 

 appear beneath the surface of the shell. We take the opportunity 

 to call attention to the difference, both in number and character, of 

 the eggs of the genera Podiceps and Colymbus, brought together by 

 systematists as the only components of their family Colymbidoe. It 

 cannot be affirmed that there is much affinity between these genera. 

 We rather prefer to arrange Colymbus among the Alcadae. Their 

 skeletons are extremely different. 



An egg of the Blackthroated, and one of the Redthroated, Diver; 

 the former larger, as would be expected, than that of the latter, and 

 of a reddish brown, with a few spots of blackish, principally at the 

 large end. The Redthroated Diver's egg is figured of a dull olive- 

 greenish brown, longitudinally spotted and blotched with reddish 

 black: we have seen a specimen of the same ground-colour, but 

 almost spotless. The Blackthroated Diver was first discovered to 

 breed within the British Isles by the gentlemen of the Sutherland 

 expedition ; and many interesting minutiae connected with its histo- 

 ry will be found in Mr. Selby's paper before adverted to. We have 

 just been examining a beautiful male, in very matured plumage, of 

 this elegant species, which was purchased in Leadenhall market, 

 where even the young birds are very seldom to be met with. The 

 young of the Redthroated Diver may there be obtained continually, 

 but specimens of that in adult plumage are not of frequent occur- 



