ould 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
races; and though they well know that each race varies slightly, for
they win their prizes by selecting such slight differences, yet they
ignore all general arguments, and refuse to sum up in their minds slight
differences accumulated during many successive generations. May not
those naturalists who, knowing far less of the laws of inheritance than
does the breeder, and knowing no more than he does of the intermediate
links in the long lines of descent, yet admit that many of our domestic
races are descended from the same parents--may they not learn a lesson
of caution, when they deride the idea of species in a state of nature
being lineal descendants of other species?

PRINCIPLES OF SELECTION ANCIENTLY FOLLOWED, AND THEIR EFFECTS.

Let us now briefly consider the steps by which domestic races have been
produced, either from one or from several allied species. Some effect
may be attributed to the direct and definite action of the external
conditions of life, and some to habit; but he would be a bold man who
would account by such agencies for the differences between a dray and
race-horse, a greyhound and bloodhound, a carrier and tumbler pigeon.
One of the most remarkable features in our domesticated races is that we
see in them adaptation, not indeed to the animal's