184 F. Finn — General Notes on Variation in Birds. [No. 3, 1902. 



pied or pure white varieties, will very commonly sliow tliem soft and 

 abraded at the tips, a serious matter for a wild bird. Accordingly we 

 find that wliite-quilled species, like white ones, are almost al'^'^' «5 large 

 and strong, and well able to defend themselves. 



Why no species is mottled or splashed or irregularly pied, as tame 

 forms and varieties commonly are, is less easy to understand. But tlie 

 fact that constitutional disturbance seems to cause a bird to become 

 temporarily so marked, may afford a clue. Such birds may be weak in 

 constitution, and unfitted to live in a wild state. The hens do not 

 appear to object to them, witness the case given by Darwin of Sir U. 

 Heron's pied , Peacock, and that of the pied Blackbird recorded by 

 Mr. Bucknill in his Birds of Surrey. This latter was evidently weakly . 

 his whiteness increased with age, and he died from natural causes. 



At the same time, some species seem incapable of producing mot- 

 tled or irregularly pied varieties; I have never seen such in the Turkey 

 or Collared Dove, and the Guinea-fowl is never mottled or splashed, 

 although its pied markings are not quite as regular as a wild bird's. 

 The Canary, on the other hand, is particularly prone to be asymmetrical 

 and irregular in its markings, as also is tlie Pigeon. 



The tendency of so many domestic birds to become coarse and heavy, 

 looking, especially marked in the Water-fowl, is probably due to the 

 adding up of small variations in that direction ; these would, especially 

 on birds performing long and perilous migrations, be weeded out in 

 each generation ; but if allowed to breed, would, in accordance with a 

 tendency well-known to fanciers, produce offspring coarser and heavier 

 even than themselves, till a conspicuous difference in appearance 

 resulted. 



It is possible that the tendency to the increased production of fleshy 

 out-growths, like the combs and wattles of poultry, is connected with 

 this assumption of a coarse habit of body ; but it must be remembered 

 that such processes are peculiarly susceptible to external influences and 

 constitutional changes, and, hence, if the environment is ever proved to 

 produce an inherited effect on any bird, might be expected to show this 

 effect early and conspicuously. 



