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Dr. Arthur G. Butler.



I want some of our younger and more enthusiastic members to put

up pairs of species which are not nearly related, and to try to

produce hybrids from them. I feel sure that the results obtained

will be of considerable interest. Closely related species, as a rule,

produce merely intermediate plumage, without any reversion to

ancestral characters. When hybrids from closely related species prove

fertile, they sometimes revert in their offspring to the characters of one

of the parents. Of course, personal experience led me to the con¬

clusion that this kind of breeding was not easy, but then my aviaries

were certainly unsuitable for work of the kind; and now that my

rather unsatisfactory outdoor aviaries have ceased to exist, and

advancing age and limited means render it impossible for me to

attempt work of the kind, I hope those who are younger, and who

possess spacious outdoor aviaries planted with bushes and creepers,

will not neglect this fascinating branch of research.


Of course, in recommending the mating of unrelated birds, I

do not suggest intercrossing distinct families ; and, as regards sub¬

families, common-sense should decide. Greenfinches were placed by

the late Dr. Sharpe in the sub-family Coccothraustince ; the Canaries,

Goldfinches, and others in the sub-family Fringillince ; but the ease

with which Greenfinches can be crossed with various Fringilline

birds, and the perfectly intermediate character of the hybrids, throw

considerable doubt upon the importance of the distinctions upon

which these sub-families are separated.


As regards the development of colours in birds, assuming

that originally they were either black or brown and white, I should

say (judging from my many years’ study of Lepidopterous insects)

that the passage from one bright colour to another follows very

much the order observable in the rainbow. Without question the

first development from white is yellow, and from black usually, if

not invariably, blue ; from brown probably purple. From yellow arise

orange, then vermilion, crimson, purple, blue, green ; from blue the

order is, I think, generally reversed, and from purple either blue or

crimson may emerge.


Blue often appears at first as a gloss on a black surface, but one

sometimes notices, in close proximity to this shot colouring, patches

of pigmented blue, as also where dark brown is shot with purple,



