584 MR. J. C. GALTON ON THE MYOLOGY OF 



pisiform bone, besides being continued on, as a strong tendon, to the palmar process of 

 the unciform bone, while the inner, or ulnar, insertion is by tendon into the base of the 

 proximal phalanx of the fifth digit, some fibres, too, taking origin from the tendon or 

 ligament described above as passing from the pisiform to the unciform bone. 



This muscle, according to Meckel 1 , is enormously developed in the Two-toed Anteater, 

 and is, moreover, divided into four parts, The opinion that these are all factors of one 

 muscle (the flexor ulnaris) appears to be supported by the fact of their coexistence with 

 a complete set of the muscles of the hand. Further on, however, Meckel regards one of 



these elements as the palmaris longns. 



Flexor carpi radiate— Arises from the outer edge of the external condyle of the 

 humerus, from a tubercle immediately below that which gives origin to the pronator 

 teres. It is inserted by a strong flattened tendon into the palmar aspect of the base of 

 the metacarpal of the index, a sesamoid bone intervening at the insertion, and partly into 

 the inferior surface of the styloid process of the radius. 



The tendon of this muscle in Dasypus sexcinctus, as I have already described, termi- 

 nates at the trapezio -trapezoid bone, after running through a groove in the scaphoid. 



The annular ligament of the palm is very strong. It is attached, on one side, to the 

 downward-looking process of the unciform bone, a flattened oval sesamoid being imbedded 

 in it not far from this attachment, and, on the other side, into a sesamoid bone (rudi- 

 ment of the pollex ?) lying close to the radial edge of the trapezium. 



Trom the anterior edge of the first- described sesamoid passes a short rounded tendon, 

 or ligament, to the root of the branch given off to the fourth digit from the common deep 



flexor tendon. 



Flexor digitorum sublimis. — With this muscle is combined, as in Dasypus, the palmaris 

 longus, both functionally and homologically. It arises from the lowest of those factors 

 of the deep flexor which take origin from the inner condyle of the humerus, at about 

 midway between the origin and insertion of the muscle, by a tendon which runs back in 

 the substance of this factor for some distance. At the carpo-metacarpal joint, after 

 passing over the strong annular ligament, it becomes tendinous, and the tendon almost 

 immediately divides into four equal-sized branches, destined one for each digit. Each 

 of these tendons seems to be separable into two layers, the external of which, at the 

 metacarpophalangeal articulation of its proper digit, is prolonged over the deeper layer, 

 to join the projecting margin, on either side, of a large grooved sesamoid which lies at 

 the above articulation— and is, moreover, inserted all along each side of the several 

 phalanges belonging to its digit, so as to form a kind of sheath for the flexor profundus. 

 The inner layer, which appears to answer to a "perforated tendon" (in human-anatomy 

 language), at about the middle of the proximal phalanx of its proper digit splits to allow 

 of the passage of the tendon of the flexor profundus, but joins again to run beneath the 

 " perforating" tendon and be finally inserted at the base of the second phalanx, through 

 the medium of a sesamoid bone. 



The tendon which passed to the "middle" digit was joined, on its inferior aspect at 

 origin, by the thin tendinous termination of a flat and delicate muscular slip which, 



1 Op. at. pp. 54l\ 545. 



