From Edward Blyth 4 January 1868
7 Princess Terrace, | Regent’s Pk,
My dear Sir,
We are indebted to you for the exceedingly interesting observation that when two very distinct races of domestic pigeons are crossed, whatever may be the colouring of the parent birds, there is a decided strong tendency for the mixed young to resume that of the wild C. livia.1 I have been studying the races of canaries lately, both wild and domestic, and I possess the true wild bird from Madeira (2 cocks), and also one of the genuine wild race which was taken here in company with greenfinches, in Octr. last, and there is another in the Z. G.2 taken in company with linnets in 1866. These birds are very like the domestic green canary, which I find is very true to its colouring when it occurs without admixture of yellow patches. But the wild bird is somewhat shorter, & has more of ashy colour about the head and neck, so that it may be readily distinguished. The song, so far as I have heard it as yet, is less varied, and I suspect the quality of it has been much improved in the domestic bird, though still it may be that my wild canaries are scarcely in full song as yet. What, however, I now wish to bring to your attention is the fact, that the breeders of mule canaries (with goldfinches, linnets, &c) are very particular in selecting a bright yellow canary hen for this purpose, even looking to its pedigree for 2 or 3 generations, to make sure that it has had no parti-coloured relations; but despite all this precaution, the progeny of the yellow hen with a goldfinch (which bird is unstreaked when adult) is tolerably sure—indeed always so far as I have hitherto seen—to be streaked, which streaked plumage must be derived from the canary mother and is a reversion to the original plumage of the canary, as in your crossed races of domestic pigeons.3 I mean shortly to contribute a paper on the canary-bird to “Land & Water”.4
With the Compts of the season, believe me to remain Yours ever Sincerely | E. Blyth—
Discusses mule canaries which show a tendency to revert to wild plumage colours.