skin round the eyes, and the skin over the nostrils swollen. Of the
first four and of the second five sub-races are distinguished.

GROUP III. is confessedly artificial, and to it are assigned _five_
Races:--(1) "Fan-tails," remarkable for the extraordinary development
of their tails, which may consist of as many as forty-two rectrices in
place of the ordinary twelve; (2) "Turbits" and "Owls," with the
feathers of the throat diverging, and a short thick bill; (3)
"Tumblers," possessing the marvellous habit of tumbling backwards
during flight, or, in some breeds, even on the ground, and having a
short, conical bill; (4) "Frill-backs," in which the feathers are
reversed; and (5) "Jacobins," with the feathers of the neck forming a
hood, and the wings and tail long.

GROUP IV. greatly resembles the normal form, and comprises _two_
Races:--(1) "Trumpeters," with a tuft of feathers at the base of the
neck curling forward, the face much feathered, and a very peculiar
voice, and (2) Pigeons scarcely differing in structure from the wild
stock.

Besides these some three or four other little-known breeds exist, and
the whole number of breeds and sub-breeds almost defies computation. The
difference between them is in many cases far from being superficial,
for Darwin has shown that there is scarcely any part of the skeleton
which is constant, and the modifications that have been effected in the
proportions of the head and sternal apparatus are very remarkable. Yet
the proof that all these different birds have descended from one common
stock is nearly certain. Here there is no need to point out its bearing
upon the theory of natural selection. The antiquity of some of these
breeds is not the least interesting part of the subject, nor is the use
to which one at least of them has long been applied. The dove from the
earliest period in history has been associated with the idea of a
messenger (Genesis viii. 8-12), and the employment of pigeons in that
capacity, developed successively by Greeks, Romans, Mussulmans and
Christians, has come down to modern times.

The various foreign species, if not truly belonging to the genus
_Columba_, are barely separable therefrom. Of these examples may be
found in the Indian, Ethiopian and Neotropical regions. Innumerable
other forms entitled to the name of "dove" are to be found in almost
every part of the world, and nowhere more abundantly than in the
Australian Re