Origin of Species Variorum

of character probably do occur; but natural selection, as will hereafter be explained, will determine how far the new characters thus arising shall be preserved. ↑

When we look to the hereditary varieties or races of our domestic animals and plants, and compare them with .. closely allied species, we generally perceive in each domestic race, as already remarked, less uniformity of character than in true species. Domestic races of the same species, also, often have a somewhat monstrous character; by which I mean, that, although differing from each other, and from .. other species of the same genus, in several trifling respects, they often differ in an extreme degree in some one part, both when compared one with another, and more especially when compared with all the species in nature to which they are nearest allied. With these exceptions (and with that of the perfect fertility of varieties when crossed, — a subject hereafter to be discussed), domestic races of the same species differ from each other in the same manner as, only in most cases in a lesser degree than, do closely-allied species of the same genus in a state of nature. I think that this must be admitted, when we find that there are hardly any domestic races, either amongst animals or plants, which have not been ranked by .. competent judges as the descendants of aboriginally distinct species, and by other competent judges as mere varieties. If any marked distinction existed between domestic races and species, this source of doubt could not so perpetually recur. It has often been stated that domestic races do not differ from each other in characters of generic value. I think it can be shown that this statement is hardly correct; but naturalists differ widely in determining what characters are of generic value; all such valuations being at present empirical. ↑ Moreover, on the view of the origin of genera which I shall presently