431 
C. J. Sundevall on the Wings of Birds. 
sinew. It seems reduced merely to act upon the capsule ol 
the joint; supination is impossible. Its development seems to 
proceed pari passu with that of the pronator superior (No. 13); 
they generally terminate close together upon the radius. 
B. On the inner (flexor) side of the cubitus, springing from 
the humeri condylus internus and the ulna. These are 
flexors in their nature. 
The muscles of the forearm seen from this side form 
three great masses or groups, the sinews of which are 
separated by the above-mentioned pits when the latter are 
present. The anterior mass consists of the preceding Nos. 1 
and 7, the posterior of Nos. 8-10, and 15, the middle one at 
the upper part of the pronator es y and then of Nos. 11 and 12. 
a . Long muscles for the hand. 
8. Flexor carpi ulnaris, from the condylus internus to the 
os pisiforme , below the fascia ulnaris or behind (beyond) it; 
first beside the ulna, then behind it, as if outside the arm. 
It is usually one of the largest cubital muscles, very fleshy 
with a strong sinew, the principal flexor muscle of the hand. 
9. Rector remigum cubiti, constitutes as it were a part of 
the preceding, forming its hinder edge from the condylus 
internus ; it gives off small sinews to all the remiges, and 
finally one to the ligamentum carpi. It therefore corresponds 
to the palmaris longus in man. 
10. Flexor digiti sublimis, a long, slender, generally 
very small muscle, attached beneath the fascia ulnaris and 
quite concealed by it. It lies either on the surface of No. 8, 
or close to it on the radial side. The sinew is usually fine, 
passes round the radial side of the os pisiforme , obliquely 
over the metacarpus to the radial side of its apex, and 
attaches itself at the base of the first phalange, quite at the 
radial margin of its articulating surface; it seems therefore 
to act only as an extensor. (The sinew may be traced to 
the base of the second phalange in Strix nisoria, Anas 
glacialis , and, according to Schopss, in Psittacus , Fulica, 
and Aptenodytes , but not in Falco palumbarius , &c.) 
