thers on reliable authority. I have classed them under four Groups, in
order to mark their affinities and degrees of difference; but the third
group is artificial. The kinds examined by me form eleven races, which
include several sub-races; and even these latter present differences that
would certainly have been thought of specific value if observed in a state
of nature. The sub-races likewise include many strictly inherited
varieties; so that altogether there must exist, as previously stated, above
150 kinds which can be distinguished, though generally by characters of
extremely slight importance. Many of the genera of the Columbidae, which are
admitted by ornithologists, do not differ in any great degree from each
other; taking this into consideration, there can be no doubt that several
of the most strongly characterised domestic forms, if found wild, would
have been placed in at least five new genera. Thus, a new genus would have
been formed for the reception of the improved English Pouter: a second
genus for Carriers and Runts; and this would have been a wide or
comprehensive genus, for it would have admitted common Spanish Runts
without any wattle, short-beaked Runts like the Tronfo, and the improved
English Carrier: a third genus would have been termed for the Barb: a
fourth for the Fantail: and lastly, a fifth for the short-beaked,
not-wattled pigeons, such as Turbits {158} and short-faced Tumblers. The
remaining domestic forms might have been included in the same genus with
the wild rock-pigeon.

_Individual Variability; Variations of a remarkable nature._

The differences which we have as yet considered are characteristic of
distinct breeds; but there are other differences, either confined to
individual birds, or often observed in certain breeds but not
characteristic of them. These individual differences are of importance, as
they might in most cases be secured and accumulated by man's power of
selection; and thus an existing breed might be greatly modified or a new
one formed. Fanciers notice and select only those slight differences which
are externally visible; but the whole organisation is so tied together by
correlation of growth, that a change in one part is frequently accompanied
by other changes. For our purpose, modifications of all kinds are equally
important, and, if affecting a part which does not commonly vary, are of
more importance than a modification in some conspicuous part. At the
present day