rves the
animals which are most useful or pleasing to him, and destroys or neglects
the others. But no doubt a far more rapid result follows from methodical
than from unconscious selection. The "roguing" of plants by gardeners, and
the destruction by law in Henry VIII.'s reign of all under-sized mares, are
instances of a process the reverse of selection in the ordinary sense of
the word, but leading to the same general result. The influence of the
destruction of individuals having a particular character is well shown by
the necessity of killing every lamb with a trace of black about it, in
order to keep the flock white; or again, by the effects on the average
height of the men of France of the destructive wars of Napoleon, by which
many tall men were killed, the short ones being left to be the fathers of
families. This at least is the conclusion of those who have closely studied
the subject of the conscription; and it is certain that since Napoleon's
time the standard for the army has been lowered two or three times.

Unconscious selection so blends into methodical that it is scarcely
possible to separate them. When a fancier long ago first happened to notice
a pigeon with an unusually short beak, or one with the tail-feathers
unusually developed, although he bred from these birds with the distinct
intention of propagating the variety, yet he could not have intended to
make a short-faced tumbler or a fantail, and was far from knowing that he
had made the first step towards this end. If he could have seen the final
result, he would have been struck with astonishment, but, from what we know
of the habits of fanciers, probably not with admiration. Our English
carriers, barbs, and short-faced tumblers have been greatly modified in the
same manner, as we may infer both from the historical evidence given in the
chapters on the Pigeon, and from the comparison of birds brought from
distant countries.

So it has been with dogs; our present fox-hounds differ from the old
English hound; our greyhounds have become lighter; the wolf-dog, which
belonged to the greyhound class, has become extinct; the Scotch deer-hound
has been modified, and is now rare. Our bulldogs differ from those which
were formerly used for baiting bulls. Our pointers and Newfoundlands do not
{212} closely resemble any native dog now found in the countries whence
they were brought, These changes have been effected partly by crosses; but
in every case the result