were as eager about pigeons as were the old Romans. The paramount
importance of these considerations in explaining the immense amount of
variation which pigeons have undergone, will likewise be obvious when we
treat of selection. We shall then, also, see how it is that the several
breeds so often have a somewhat monstrous character. It is also a most
favourable circumstance for the production of distinct breeds, that male
and female pigeons can be easily mated for life; and thus different breeds
can be kept together in the same aviary.

I have discussed the probable origin of domestic pigeons at some, yet quite
insufficient, length; because when I first kept pigeons and watched the
several kinds, well knowing how truly they breed, I felt fully as much
difficulty in believing that since they had been domesticated they had all
proceeded from a common parent, as any naturalist could in coming to a
similar conclusion in regard to the many species of finches, or other
groups of birds, in nature. One circumstance has struck me much; namely,
that nearly all the breeders of the various domestic animals and the
cultivators of plants, with whom I have conversed, or whose treatises I
have read, are firmly convinced that the several breeds to which each has
attended, are descended from so many aboriginally distinct species. Ask,
as I have asked, a celebrated raiser of Hereford cattle, whether his cattle
might not have descended from Long-horns, or both from a common parent-
stock, and he will laugh you to scorn. I have never met a pigeon, or
poultry, or duck, or rabbit fancier, who was not fully convinced that each
main breed was descended from a distinct species. Van Mons, in his
treatise on pears and apples, shows how utterly he disbelieves that the
several sorts, for instance a Ribston-pippin or Codlin-apple, could ever
have proceeded from the seeds of the same tree. Innumerable other examples
could be given. The explanation, I think, is simple: from long-continued
study they are strongly impressed with the differences between the several