430 
C. J. Sundevall on the Wings of Birds. 
the finger and turns it a little so that the tips of the largest 
feathers are turned downwards; it likewise flexes the thumb. 
(The course of the sinew is analogous to that of the FI. dig. 
prof. No. 11.) 
4. Extensor indicis proprius (essentially an extensor pro¬ 
fundus, answering to the flexor profundus), beneath the 
preceding, nearly between the radius and ulna, attached to 
the radius.—The sinew runs to the anterior margin of the 
metacarpus through the same sheath as the preceding, passes 
over the bend of the latter, and is attached at the base of 
the second phalange on the outer side, near the flexor 
profundus. 
5. Extensor carpi ulnaris, visible externally near No. 3, is 
always firmly united with the ulna by cellular tissue, behind 
No. 6, and usually commences in common with the latter 
from the condylus externus, or on the surface of its basal 
sinew.—The sinew passes backward over the apex of the 
ulna, and attaches itself at the base of the os metacarpi on 
the outer side. (Called by Schopss, “ abductor metacarpi .”) 
b. Short muscles (attached to the radius or ulna). 
6. Humero-ulnaris externus, commences in a point, with 
a short, strong sinew, upon the condylus externus ; it is 
large, but quite covered by the preceding; it is broadly 
attached and generally spread out upon the anterior surface 
of the ulna (near the ligamentum interosseum). It seems 
to serve both as a flexor and to give firmness to the 
joint. (Called flexor profundus antibrachii by Schopss ; see 
further on under No. 15.) Leaving out of consideration 
some difference in position, it might be regarded as the 
same as the anconceus parvus in man. Except this, there is 
nothing with which it can be compared. I have, however, 
adopted a new name for it; for the reason of this see 
further on. 
7. Supinator radialis is only one in birds, concealed under 
No. 1, in front of the radius; it springs from the condylus 
externus, united with No. 3, but beneath it; and is attached 
to the middle of the anterior surface of the radius without a 
