[56] It sometimes happens in very dry seasons that the feathers of the young birds cannot develop naturally; a bath of tepid water employed on such an occasion by Madame * * * was so successful that I cannot do better than recommend it. The same lady succeeded equally well in similar circumstances in hatching late eggs; she plunged them for some minutes in water heated to the degree of incubation, and immediately replaced them under the mother; in a short time she enjoyed the pleasure of seeing the little ones make their appearance. This interesting experiment may be applied to all sorts of birds, and may be particularly useful in regard to those of the poultry yard.--TRANSLATOR. [57] Green birds, bullfinches, and even chaffinches, yellowhammers, and the like, have been tried; but the difficulty augments with the difference of species and food: for example, I have never seen a male canary very fond of a female yellowhammer, nor a male of the latter kind of a female canary, though the plumage may be selected so as to offer a striking resemblance. An ardent bullfinch will sometimes yield to the allurements of a very ardent hen canary. I have myself witnessed it; but with every care, it is seldom that the eggs prove fruitful, and produce young. Dr. Jassy, however, writes me from Frankfort, that he has obtained mules of a bullfinch and canary, by making other canaries sit on the eggs and bring up the young; and that this plan is pursued in Bohemia. A tufted or crested female should never be chosen, because this ornament is very unbecoming to the large head of a mule. "My bullfinch," he adds, "is so attached to the female canary that he mourns all the time they are separated, and cannot bear any other bird." I possess a nightingale which, having been for a long time shut up with a female canary, lives very sociably with her, and sings as usual; indeed, he was so ardent in the spring, that he paired with her in my presence, but the eggs were unproductive. I shall try next spring, if the same thing happens, to give the eggs to another sitter.--AUTHOR. [58] Some do this naturally, others are taught it in their youth, by covering the cage and keeping them in the dark during the day, long enough for them to be hungry; they are thus forced to eat by candle-light. Gradually they become accustomed to this, and at last sing.--AUTHOR. [59] Nothing is more delightful than to hear them imitate the song of the nightingale; I prefer those which have this talent, and I never fail to possess one.--AUTHOR. [60] In Britain it is partly migratory and partly stationary.--TRANSLATOR. [61] If it is difficult to induce larks to sit, it appears to be very easy to make them take care of a young brood. "The instinct," says Buffon, "which induces hen larks to bring up and watch over a brood appears sometimes very early, even before that which disposes them to become mothers, and which, in the order of nature, ought, it would seem, to precede it.