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 have 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?
_Selection_. Let us now briefly consider the steps by which domestic
races have been produced, either from one or from several allied
species. Some little effect may, perhaps, be attributed to the direct
action of the external conditions of life, and some little to habit;
but he would be a bold man who would account by such agencies for the
differences of 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 or
plant s own good, but to man s use or fancy. Some variations useful to
him have probably arisen suddenly, or by one step; many botanists, for
instance, believe that the fuller s teazle, with its hooks, which
cannot be rivalled by any mechanical contrivance, is only a variety of
the wild Dipsacus; and this amount of change may have suddenly arisen
in a seedling. So it has probably been with the turnspit dog; and this
is known to have been the case with the ancon sheep. But when we
compare the dray-horse and race-horse, the dromedary and camel, the
various breeds of sheep fitted either for cultivated land or mountain
pasture, with the wool of one breed good for one purpose, and that of
another breed for another purpose; when we compare the many breeds of
dogs, each good for man in very different ways; when we compare the
game-cock, so pertinacious in battle, with other breeds so little
quarrelsome, with everlasting layers which never desire to sit, and
with the bantam so small and elegant; when we compare the host of
agricultural, culinary, orchard, and flower-garden races of plants,
most useful to man at different seasons and for different purposes, or
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