204 
Proceedings of the Royal Society of Edinburgh. [Sess. 
Abductor Minimi Digiti. 
Origin. — A slip from the pisiform and the inner part of the anterior 
annular ligament. A deeper head from the inner part of the unciform, 
situated behind a similar head of the flexor brevis muscle. 
Insertion. — Into the inner side of the base of the proximal phalanx of 
the little finger. 
Nerve Supply. — From the deep division of the ulnar nerve which passes 
between the two heads of origin. 
Structure. — The belly formed by the two heads is very short, the 
tendon proportionately long. The latter seems much too strong for the 
feeble muscle. 
Flexor Brevis Minimi Digiti. 
Origin .■ — There are, as in the last muscle, two heads of origin ; one from 
the front and inner side of the pisiform, another (lying in front of a similar 
slip to the last muscle) from the hook of the unciform and the inner part of 
the anterior annular ligament. 
Insertion.- — By short tendinous fibres into the sesamoid bone on the 
front of the 5tli metacarpo-phalangeal joint, and by fleshy fibres into the 
front of the base of the proximal phalanx of the little finger. On following 
the fleshy fibres down the finger they are found to give place to a tendon 
which passes downwards to find attachment to the inner margin of the 
1st and 2nd phalanges and to the pulp of the finger. 
Nerve Supply. — By two twigs from the deep division of the ulnar nerve 
which passes between its two heads of origin. 
Structure. — The pisiform head is muscular, the other is tendinous. The 
remainder of the muscle is fleshy till it approaches its insertion, of which 
the structure has been fully described. 
Opponens Minimi Digiti. 
Origin. — From the hook of the unciform process, the anterior annular 
ligament, and the anterior carpal ligaments. 
Insertion. — Into the inner side of the front of the 5th metacarpal bone 
in its whole length. 
Nerve Supply. — By a twig which is given off from the deep division of 
the ulnar before that nerve pierces the muscle. The twig accompanies its 
parent trunk till it reaches the deeper plane of the palm. 
Structure. — The muscular fibres are largely intermixed with fibrous 
tissue. The muscle is blended partly with the small palmar interosseous 
