THE COLUMBINE. 109 



1. COLUMBA. 



For the sake of more easy comprehension, I retain this great genus in its old extent, although 

 I fully believe that it may be broken up into several genera with the same justice as Psittacus, 

 Falco, and others of similar extent, for this opinion is supported by the great differences in the 

 pterylosis even of the few species that I have examined. The general characters were only as follows : 



The contour-feathers throughout have no after-shaft, and they stand close together, forming 

 strong tracts. No down-feathers are observed amongst them, and these are also wanting 

 on most of the spaces ; I have detected a few only on the inferior wing-space, and the lateral 

 spaces of the trunk. Even the young birds while still in the nest have no down-feathers, but 

 simple yellow tufts of bristles appended to the tips of the contour-feathers. In this respect they 

 precisely agree with the Passerinse (see p. 74). The form of the tracts on the dorsal surface is 

 the same in all the species, always presenting a strong, furcate anterior part of the spinal tract, 

 and a posterior part, weakened at its commencement and margins, and divided by a narrow 

 longitudinal space, from which, however, the broad femoral tracts are pretty distinctly separated. 

 The anterior part is very clearly separated from the inferior tract by the lateral neck-spaces, 

 which ascend nearly to the head. The inferior tract is broad at its commencement on the throat, 

 and divides at the lower part of the neck ; its pectoral tract is usually widened throughout, 

 seldom narrow, and furnished with a distinct outer branch. The oil-gland, when it occurs, is 

 obtusely cordate and perfectly naked. Its two halves have very thin walls, and possess a very 

 wide cavity, extending through the whole gland. The remiges, which are usually long and 

 pointed, amount at the utmost to twenty-five, of which the second is the longest. 



In accordance with the number of rectrices, we may establish the following two groups : 



I. PIGEONS WITH TWELVE RECTRICES. 



The species belonging to this group, which includes the whole of our indigenous Pigeons, 

 exhibit in their pterylosis the form already described, and figured (Plate VII, figs. 1 and 2) as that 

 of Columba livid ; they all have a very broad and strong inferior tract, occupying the whole lower 

 surface of the neck, dividing only immediately in front of the furcula, then becoming broader on 

 the breast, where, however, it forms no outer branch, but is continued, widened throughout, as 

 far as the hinder margin of the mmculus pectoralis major, and becomes narrowed into the ventral 

 portion as it runs along upon this margin. The ventral portion is short, half the width of the 

 pectoral portion, and terminates at the anus. The region of the outer branch in the pectoral 

 portion is very strong, and emits a few rows of feathers in front, running to the hypopterum. 

 Above we find beside the dorsal tract a strong broad scapular tract, which is pointed behind. 



In C. livia the division of the hinder part of the dorsal tract, which reaches to the caudal 

 pit, is remarkably narrow, and the broad femoral tracts are connected by a few feathers with 

 this hinder portion ; in C. tigrina I found a much broader spinal space, and the lumbar tract 

 was free all round. The other species of this section, such as C. cenas, palumbus, turtur, and 

 risoria, agree more especially with the domestic Pigeon. C, talpacoti presents a remarkable 

 peculiarity in its short, obtuse wings, the third, fourth, and fifth feathers of which are furnished 

 with an angular emargination, gradually becoming weaker, towards the apex of the outer half of 

 the vane, whilst the fourth alone possesses a very acute projecting angle at the base of the inner 

 vane. The second primary is the longest, but the first and third are but little shorter. 



