112 PTERYLOGRAPHY. 



although pretty strong and densely feathered ; they are never so close, however, even in the 

 outer branch of the inferior tract, as in the Passerinse. The dorsal tract always starts simply 

 from the nape, and either remains simple to the oil-gland, or divides in the scapular region into 

 two limbs, which afterwards coalesce again and circumscribe a lanceolate spinal space. The 

 dorsal tract is also cither of uniform strength in all parts, which is the most usual case, or it has a 

 gap between the shoulder-blades, situated at the commencement of the furcation, and is further 

 remarkable from the fact that the feathers of the anterior part are stronger than those of the 

 hinder part. I have met with this condition only in Numida ; a similar one as regards the 

 feather-structure, although without a true gap, occurs in Penelope. Both forms, but especially 

 the former, strikingly approach the type of the Pigeons. The axillary tracts are always broad 

 but short ; the lumbar tracts are uncommonly large and strong, but generally quite free, separated 

 from the rump-portion of the dorsal tract, and composed of long, strong, but chiefly downy 

 feathers, the length of which appears very remarkable when the legs are drawn backwards. 

 The inferior tract is sometimes simple (Gallus, Pavo), sometimes divided at its commencement 

 on the throat (Crypturus) , but in the former case always divides, before reaching the middle 

 of the neck, into two limbs, which gradually diverge and at the same time become broader. 

 From the very commencement of the pectoral surface, therefore, they cover the latter completely, 

 with the exception of a narrow space close to the crest of the sternum, and are also united 

 externally with the axillary tracts. After a short course this breadth ceases, and we may at 

 once distinguish a strong and always wedge-shaped outer branch, the strongly feathered outer 

 margin of which runs parallel to the inner margin of the pectoral band, whilst the inner margin 

 forms an acute angle with the main stem. The branch usually terminates at the hinder margin 

 of the musculus pectoralis major ; it rarely passes beyond this (as in Crypturus, Plate VII, fig. 11), 

 and becomes united posteriorly to the lumbar tract. The characters of the main stem are 

 exactly the reverse of those of the branch it is therefore very narrow and weakened, and runs 

 down close to the crest of the sternum. On reaching the ventral surface, the two bands do not 

 separate from each other, but frequently coalesce to form a single stem, which is directed straight 

 to the anus, and terminates there. This very peculiar form of the inferior tract is the true and 

 genuine Gallinaceous type, which becomes indistinct in proportion as the general characteristic 

 Gallinaceous structure is effaced hence it is deficient in Crypturus (Plate VII, fig. 11), and gives 

 place to a Columbine structure. 



In striking harmony with this form of the inferior tract is the short, rounded form of the 

 wings, which is an equally genuine Gallinaceous structure. When carefully examined, the wings 

 of the Gallinacese present from twenty-two to twenty-nine rerniges, of which ten or eleven are 

 inserted upon the pinion, and the fourth, fifth, and sixth are usually the longest ; whilst the pre- 

 ceding and following feathers are uniformly shortened and graduated, and the eleventh is the 

 smallest of all. This very small feather is sometimes the last on the pinion (P/iasianus), some- 

 times the first on the ulna (Tctrao), and appears to be frequently deficient (for example, in 

 Nunnda, Polyplectron, Lophophorus, Crax, Penelope, and Crypturus}. The next is again as long 

 as the tenth ; thence onwards to the elbow-feather (the eighteenth, nineteenth, or twentieth) 

 each feather increases a little in length, the remainder (from the elbow) being rapidly 

 diminished graduatedly. By this means the extended wing acquires its peculiar bilobed appear- 

 ance. On the thumb, also, I have always found four feathers, but in the tail all the numbers that 

 occur in the whole class, namely, ten, twelve, fourteen, sixteen, eighteen, and twenty are met with. 



