ing so great in
external characters and relatively so slight in internal parts or organs.
Man can hardly select, or only with much difficulty, any deviation of
structure excepting such as is externally visible; and indeed he rarely
cares for what is internal. He can never act by selection, excepting on
variations {39} which are first given to him in some slight degree by
nature. No man would ever try to make a fantail, till he saw a pigeon with
a tail developed in some slight degree in an unusual manner, or a pouter
till he saw a pigeon with a crop of somewhat unusual size; and the more
abnormal or unusual any character was when it first appeared, the more
likely it would be to catch his attention. But to use such an expression as
trying to make a fantail, is, I have no doubt, in most cases, utterly
incorrect. The man who first selected a pigeon with a slightly larger tail,
never dreamed what the descendants of that pigeon would become through
long-continued, partly unconscious and partly methodical selection. Perhaps
the parent bird of all fantails had only fourteen tail-feathers somewhat
expanded, like the present Java fantail, or like individuals of other and
distinct breeds, in which as many as seventeen tail-feathers have been
counted. Perhaps the first pouter-pigeon did not inflate its crop much more
than the turbit now does the upper part of its oesophagus,--a habit which
is disregarded by all fanciers, as it is not one of the points of the
breed.

Nor let it be thought that some great deviation of structure would be
necessary to catch the fancier's eye: he perceives extremely small
differences, and it is in human nature to value any novelty, however
slight, in one's own possession. Nor must the value which would formerly be
set on any slight differences in the individuals of the same species, be
judged of by the value which would now be set on them, after several breeds
have once fairly been established. Many slight differences might, and
indeed do now, arise amongst pigeons, which are rejected as faults or
deviations from the standard of perfection of each breed. The common goose
has not given rise to any marked varieties; hence the Thoulouse and the
common breed, which differ only in colour, that {40} most fleeting of
characters, have lately been exhibited as distinct at our poultry-shows.

I think these views further explain what has sometimes been
noticed--namely, that we know nothing about the origin or his