|
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
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
the upper part of the œsophagus. The Jacobin has the feathers so much reversed along the back of the neck that they form a
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
instead of twelve or
normal number in all
of the great pigeon
these feathers are kept expanded, and are carried so
that in good birds the head and tail
the oil-gland is quite aborted. Several other less distinct breeds might
specified. |
| In the skeletons of the several breeds, the
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
→OMIT
caudal and sacral vertebræ
→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 strict correlation with the length of beak), the size of the crop and of the upper part of the œsophagus; the development and abortion of the oil-gland; the number of the primary wing and caudal feathers; the relative length of
and tail to each other and to the body; the relative length of
→the leg and foot;
the number of scutellæ on the toes, the development of skin between the toes, are all points of structure which are variable. The period at which the perfect plumage is acquired varies, as does the state of the down with which the nestling birds are clothed when hatched. The shape and size
|
