The Oologisis' Record, June 1, 1923. . .33 



At this point we again reach a controversial question. Are 

 accidental mutations hereditary and, if so, are not environmental 

 changes also hereditary ? To take the second question first. 

 Many naturalists claim that variations caused by environment are 

 not transmissible from parent to child and that whilst environment 

 may affect the outer form or appearance of a bird, it in no way 

 affects the protoplasm, and that neither spermatozoa nor ovaries 

 are influenced thereby. But surely these naturalists are wrong. 

 We have many cases am^ongst birds, as indeed amongst mammals, 

 from man downwards, which have become permanently changed 

 within historic times — such, for instance, as the Chaffinch of the 

 Canary Islands, the ^fyna [Acridotheres tristis) of India and Tasmania, 

 the House Sparrow or Europe and America. If the environmental 

 variation had no effect on the protoplasm, each young bird bom 

 within its new habitat would be identical with that born in its 

 original country and no change would be observable imtil environ- 

 ment had had time to act upon the individual concerned. But 

 this is not the case. Each young bird is hatched and acquires 

 first plumage which from the very beginning is different to that 

 of its cousin at home. Environment stamps its mark on young 

 and old alike, increasing with each generation until perfection of 

 adaptation is reached and in tim.e the effect on the outer bird is 

 communicated to the protoplasm, which in turn determines the 

 same effect on the young. The birds, in fact, breed true, so that 

 if the adults are brought back to the country of their origin they 

 will continue to breed true to the variation environmentally acquired 

 in the land of their adoption until again affected, after a certain 

 number of generations, b\^ the environment of their original 

 home. 



Reverting to the first question, are accidental mutations 

 hereditary ? This can, of course, be at once answered in the 

 affirmative by the rabbit-fancier, the poultry farmer, etc., who 

 within the lifetime of one man produce more or less permanent 

 varieties by breeding from carefully selected stock. But in the 

 production of these varieties man usurps the place of environment 

 in each generation by continually selecting the freaks or varieties 

 which show the greatest advance towards the object he has in 

 view. In this way we have produced the white albino rabbit, the 

 long-tailed cocks of Japan, varieties of dogs and cats and all domestic 

 animals. These races are all produced purely by selection, man 



