differences in their skulls. The carrier, more especially
the male bird, is also remarkable from the wonderful development of the
carunculated skin about the head, and this is accompanied by greatly
elongated eyelids, very large external orifices to the nostrils, and a
wide gape of mouth. The short-faced tumbler has a beak in outline almost
like that of a finch; and the common tumbler has the singular inherited
habit of flying at a great height in a compact flock, and tumbling in
the air head over heels. The runt is a bird of great size, with long,
massive beak and large feet; some of the sub-breeds of runts have very
long necks, others very long wings and tails, others singularly short
tails. The barb is allied to the carrier, but, instead of a long beak,
has a very short and broad one. The pouter has a much elongated body,
wings, and legs; and its enormously developed crop, which it glories in
inflating, may well excite astonishment and even laughter. The turbit
has a short and conical beak, with a line of reversed feathers down the
breast; and it has the habit of continually expanding, slightly, the
upper part of the oesophagus. The Jacobin has the feathers so much
reversed along the back of the neck that they form a hood, and it
has, proportionally to its size, elongated wing and tail feathers. The
trumpeter and laugher, as their names express, utter a very different
coo from the other breeds. The fantail has thirty or even forty
tail-feathers, instead of twelve or fourteen, the normal number in all
the members of the great pigeon family: these feathers are kept expanded
and are carried so erect that in good birds the head and tail touch: the
oil-gland is quite aborted. Several other less distinct breeds might be
specified.

In the skeletons of the several breeds, the development of the bones of
the face, in length and breadth and curvature, differs enormously. The
shape, as well as the breadth and length of the ramus of the lower jaw,
varies in a highly remarkable manner. The caudal and sacral vertebrae
vary in number; as does the number of the ribs, together with their
relative breadth and the presence of processes. The size and shape of
the apertures in the sternum are highly variable; so is the degree
of divergence and relative size of the two arms of the furcula. The
proportional width of the gape of mouth, the proportional length of the
eyelids, of the orifice of the nostrils, of the tongue (not always in
stri