88 



HEWIT90N S " BRITISH OOLOGY. 



clearly ascertained, respecting the former, that this singular bird 

 lays from four to six eggs in the course of the spring and summer, 

 but not on consecutive days, as in those birds which incubate their 

 own, but a week, or even considerably more, intervening between 

 their successive depositions. This fact is perfectly explicable by a 

 reference to a peculiarity in the bird's anatomy, which the present 

 is not a fitting occasion to treat of: for whatever purpose this was 

 designed we as yet know not ; but on it evidently depends its devi- 

 ation from the ordinary mode of propagation. It is well known 

 that the female Cuckoo is much in the habit of watching birds that 

 are carrying building materials, during which time she has always 

 an egg gradually maturing, which will not separate from the ovari- 

 um until, perhaps, such time as the nest is ready for its reception. 

 Still she cannot retain her egg when once in the oviduct, as has 

 been suggested, as is proved by her occasionally laying into a half- 

 finished nest. 



The two following plates exhibit figures of eggs of our four spe- 

 cies of Columba, all spotless white, and differing' only in size. 



Two eggs of the Common Pheasant, a light one and a dark one, 

 though by no means shewing the extremes of variation. We have 

 them considerably darker. Those of white Pheasants are very much 

 paler; and we believe that the Ring-necked variety (?) or blended 

 species (?) produces in general lighter eggs than the common sort. 



An example of the egg of the noble Capercailzie Grouse (Tetrao 

 urogallusj, now, alas ! no longer a member of the indigenous British 

 Fauna, if, indeed, we can as yet again lay claim to it as an intro- 

 duced species. It is, in size, equal to that of a game hen, reddish- 

 cream colour, interspersed all over with numerous rufous-brown 

 specks of different sizes. Also that of the Black Grouse, (T.te- 

 trix), so ludicrously made a distinct &enus of by Swainson, who 

 styles it Lyrunts, solely from a mere difference in the form of the 

 tail. It differs only from that of the other in being rather smaller, 

 with the specks less uniformly diffused and larger. As is remarked, 

 the dots are seldom, however, so large as is represented. 



We have next three of those adornments to cabinets of British 

 eggs, those of the Red Ptarmigan, (Lagopus Britannicus) ; and 

 beautifully represented they are. These eggs generally sell for a 

 shilling a-piece in the London Markets, and present a great number 

 of beautiful varieties. 



Eggs of the Grey Partridge (Perdix cinerea), two in number — 

 a light and a dark specimen. We have examples both lighter and a 

 shade darker, and varying remarkably in size and form. One of 



