421 
C. J. Sundevall on the Wings of Birds. 
of the wing. In all non-Song-birds which have the feathers 
of this series small, there seems to he a distinct tendency, 
under certain circumstances, to turn them right . 
2. The tectrices infrabrachiales s. plumce infracubit ales &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 post- 
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 Ficus 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 
2 h 
SER. V.-VOL. IV. 
