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Show 26 DOMESTIC PIGEONS. [CRAP. I. ences in their skulls. The carrier, more especially the mn.le bird, is also remarkable from the wonderful deveio~ment of the caruncula ted skin above the head, and this IS accompanied by greatly elongated ey~lids, very large external orifices to the nostrils, and a wide gape of mouth. The short-faced tumbler has a beak in outhne alm?st like that of a finch· and the common tumbler has th~ singular and strictly inherited habit of flying at a great height in a co1npact flock, and tumbli~g in ~he air head ov_er 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 ~ings .and tails, othe:r:s singularly short tails. The barb IS allied to the earner, but, instead of a very long beak, has a very short and very broad one. The pouter has a much elongated body, win as, and legs; and its enormously ~evelope.d crop, whi~h it glories in inflating, ma:y well excite aston1shment and even laughter. The turbit has a very 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 resophagus: The J acobin has the feathers so Inuch reversed along the back of the neck that they form a hood, and it has, proportionally to its size, much elongated wing an9. tailfeathers. The trumpeter and lau~her, as their names express, ut.ter a very different coo from the other breeds. The fantail has thirty or even forty tailfeathers, instead of twelve or fourteen the normal number in all members of the great pige~n fan1ily; and these feathers are kept expanded, an~ are carried so erect that in good birds the head and ta1l touch· the oil-gland is quite aborted. Several other less distin~t breeds might have been 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 :vell as t~e breadth and length of the ramus of the lower Jaw, vanes jn a highly remarkable manner. The number of the caudal and sacral vertebrrn vary; as does the number of the ribs, together with their relative breadth and the pr~sence of processes. The size and shape of the apertures In the CHAP. I.] DOMESTIC PIGEONS. 27 sternum are highly vai·iable; 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 lenath of the eyelids, of the orifice of the nostrils, of the ton~ue (not always in strict correlation with the length of bea~) the size of the crop and of the upper part of the resopl;agus; the developn1ent and abortion of the oilaland · the number of the primary wing and caudal ?eathe;.s · the relative length of wing and tail to each other and to the body; the relative length of leg and of the feet· the number of scutellrn on the toes, the development of' skin between the toes, are all points of structure which are variable. The period at which the perfect plunlaae is acquired varies, as does the state of the down with which the nestling birds are clothed when hatched. The shape and size of the eggs va:y. The manner of flight differs remarkably; as does In some breeds the voice and disposition. Lastly, ~ certain ?reeds, the males and females have con1e to differ to a shght degree from each other. Altoaether at least a score of pigeons might be chosen ~hich if shown to an ornithologist, and he were told that they were wild birds, would certainly, I think, be ranked by him as well-defined species. Moreover, I do not believe that any ornithologist would place the Enalish carrier, the short.faced tumbler, the runt, the bai~, pouter, and fantail in the same genus ; m?re e~pecially as in each of these breeds several truly-Inherited sub-breeds, or species as he might have called them, could be shown hirn. Great as the differences are between the breeds of pigeons, I am fully convinced that the common opinion of naturalists is correct, namely, that all have descended from the rock-pigeon (Oo!uniba livia), includi.ng un~er this term several geogr~phiCal races o:; ~ub .. spemes, whiCh differ from each other In the most tnfling respects. As several of the reasons which have led me to this belief are in some degree applicable in other cases, I will h~r~ briefly give them. If the several breeds are not varieties, and have not proceeded from the rock-pigeon, they must have |