lfig F. Finn — General Notes on Variation in Birch. [No. 3, 



spontaneous variation, since it is hard to find it in a really unselected 

 state. Both the Western and Eastern forms produce chequered indivi- 

 duals when wild. 



By studying Pigeons not selected for colour, or living in a semi- 

 feral state, as in towns where they pick up their living in the streets, 

 the following leading types are evident :— 



(a) As in wild type ; common, but not the most numerous. 



(6) Silver, a pallid form, greyish cream-colour with the wing-bars 

 and tail-tip dark drab ; bill flesh-colour. Not uncommon. Correct for 

 many breeds. 



(c) Blue-chequer, with the back and wing-coverts mottled with 

 black; very common, in fact the most numerous in semi-feral pigeons, 

 and also occurring frequently among birds in a perfectly wild state. 



(d) Silver-chequer, the corresponding marking in cream and drab. 



(e) A sandy-red form with grayish white primaries, rump and tail; 

 very common. Often the wings are chequered with whitish, when the 

 bird is a red chequer. 



(/) Silver-dun ; a sort of ashy-grey, with dark-reddish-brown 

 neck and wing-bars ; no tail-bar ; very common. 



(g) Black, of a dull slaty shade, very common. 



(h) Pure white ; rare. 



Intermediate pied and splashed forms are numerous, generally 

 asymmetrical ; the quills and tail are often more or less white, or 

 again may be markedly darker than the body when this is or white. In 

 this case the marking is symmetrical, but ill-defined. Blue and 

 black, blue and blue chequer, and blue chequer and black, grade into 

 each other commonly; but not, as a rule at all events, any of the blue 

 shades with red or silver ; nor do these last grade into black as a rule. 



The beak is fleshy-white in light forms, the feet and eyes remain- 

 ing normal, except in whites, where the eyes are dark ("bull" of 

 the fancy). 



The pigeon certainly shows convincingly what can be done by 

 careful selection of structural variations, for in its feral state it is 

 not by any means a structurally variable bird. In form a lot of feral 

 pigeons are as uniform as most wild birds, and much more so than 

 some species. 



The Bddgerigar (Melopsittacus undulatns). This little Australian 

 Parrakeet, known in books as the Undulated Grass-Parrakeet, has been 

 exported only during the last half-century, and many are still brought 

 over ; but it is largely bred in captivity. 



In domestication the usual colour is the typical one, but three varie- 

 tal forms occur. 



