C. J. Sunclevall on the Wings of Birds. 421 



of the wing. In all non-Song-birds which have the feathers 

 of this series small, there seems to be a distinct tendency, 

 under certain circumstances, to turn them right. 



2. The tectrices infrabrachiales s. plumcB infracubitales &c. 

 (inferior arm-feathers, figs. 4 and 8, q) are seated upon the 

 lower surface of the arm itself, the hand, &c., and turn their 

 reverse side towards the part upon which they are inserted, 

 as feathers usually do. But the edges of those on the cubitus 

 have a reversed position, so that, although belonging to the 

 underside of the wing, they lie like the margins of the 

 remiges. This is particularly remarkable, as such a reversed 

 position as compared with the other feathers also occurs in 

 those which clothe the outer surface of the cubitus. 



These feathers appear to me to show several differences 

 from the others in number, size, position, &c., of which the 

 following few remarks are only to be regarded as examples. 

 In order to define their position more accurately, we may, if 

 necessary, distinguish between radiates, ulnares, and j^ost- 

 ulnares, according as they are placed upon one or other of 

 the wing-bones or quite posteriorly, with the preceding, behind 

 the great sinew of the cubitus [fascia tendinea ; see further 

 on), which last is the most usual of all, for the first series 

 there situated occurs in all birds and is often alone. It is 

 to be remarked that we are speaking here only of series 

 which consist of true feathers, of which there are but few, 

 usually only 1-3 ; but in most birds, except the Song-birds, 

 there is an abundance of down. 



The birds provided with a singing-apparatus have in general 

 only a single series of inferior cubital feathers, which are 

 inserted behind the fascia ulnaris, are long and soft, and 

 cover the preceding feathers (fig. 8, q). In Corvus, however, 

 there is also a small series close behind the first. 



In Picus and Cypselus also the first series alone is deve- 

 loped, but not so long; the second series is rudimentary. 

 Columba has a moderate-sized and a small series upon the 

 ulnar surface ; then down ; and then two small, nearly rudi^ 

 mentary, radial series. In Psittacus amazonicus there are 

 two tolerably large postulnar series ; then three small series 



SER. V. VOL. IV. - 2 H 



