actions,
performed without experience by the young, and in nearly the same manner
by each individual, performed with eager delight by each breed, and
without the end being known--for the young pointer can no more know that
he points to aid his master, than the white butterfly knows why she lays
her eggs on the leaf of the cabbage--I cannot see that these actions
differ essentially from true instincts. If we were to behold one kind
of wolf, when young and without any training, as soon as it scented its
prey, stand motionless like a statue, and then slowly crawl forward with
a peculiar gait; and another kind of wolf rushing round, instead of at,
a herd of deer, and driving them to a distant point, we should assuredly
call these actions instinctive. Domestic instincts, as they may be
called, are certainly far less fixed than natural instincts; but
they have been acted on by far less rigorous selection, and have
been transmitted for an incomparably shorter period, under less fixed
conditions of life.

How strongly these domestic instincts, habits, and dispositions are
inherited, and how curiously they become mingled, is well shown when
different breeds of dogs are crossed. Thus it is known that a cross with
a bull-dog has affected for many generations the courage and obstinacy
of greyhounds; and a cross with a greyhound has given to a whole family
of shepherd-dogs a tendency to hunt hares. These domestic instincts,
when thus tested by crossing, resemble natural instincts, which in a
like manner become curiously blended together, and for a long period
exhibit traces of the instincts of either parent: for example, Le Roy
describes a dog, whose great-grandfather was a wolf, and this dog
showed a trace of its wild parentage only in one way, by not coming in a
straight line to his master, when called.

Domestic instincts are sometimes spoken of as actions which have become
inherited solely from long-continued and compulsory habit, but this is
not true. No one would ever have thought of teaching, or probably could
have taught, the tumbler-pigeon to tumble--an action which, as I have
witnessed, is performed by young birds, that have never seen a pigeon
tumble. We may believe that some one pigeon showed a slight tendency to
this strange habit, and that the long-continued selection of the best
individuals in successive generations made tumblers what they now are;
and near Glasgow there are house-tumblers, as I hear from Mr. Brent,