| OCR Text |
Show 864 MR. ST. GEORGE MIVART ON THE [Dec. 6, it is inserted into the anterior part of the outer surface of the scapula, near its summit, between tbe insertions of the levator claviculse and posterior suprascapular. Latissimus dorsi (figs. 1, 6, 8, L. D). This rather large muscular sheet springs from the strong fascia which binds down the erector spinse, and from the vertebral portions of the third and fourth of those ribs which extend to the sternum. Its origin extends forward beneath the trapezius, which thus overlaps it. It is inserted into the ulnar side of the upper part of the humerus, a little distance below tbe insertion of the subscapularis. No tendon passes down on its inner side, as it does in the Iguana. Serratus magnus* (figs. 6, 7, 8, & 13, S. M). This is much divided, consisting of one large and three smaller portions. The first springs from about the angles of the first three ribs which join the sternum, and is inserted into the posterior margin of the scapula. The other three parts spring, two from the first rib, and one from the second, above their angles, and are inserted into the inner side of the upper part of the scapula and into its posterior margin. Anterior suprascapular (figs. 1, 6, & 13, <S"). A muscle which may perhaps be conveniently thus distinguished springs from the anterior part of the outside of the scapula, and is strongly inserted outside the head of the humerus, behind the subclavius, and in front of the insertion of the deltoid. It has the levator claviculse and omohyoid in front, the posterior suprascapular behind. The posterior suprascapular^ (figs. 1, 6, 13, S2) is a thick fleshy muscle, which arises from the posterior part of the outer side of the scapula, and is inserted into the humerus just above (behind when the humerus is vertical) the insertion of the deltoid. The deltoid appears to consist of two parts. The upper or posterior portion (tigs. 1,6, 7, & 13, Dl) arises from the inner end of the ventral margin of the coracoid groove of the sternum, just external to tbe origin of the second part of the deltoid, and internal to and overlapped by the sterno-mastoid. Some fibres arise from the spur of the epicoracoid. Passing down superficially to the subclavius, it is inserted into the head of the humerus, between the insertions of the pectoralis and of the second part of the suprascapular. The second, lower or anterior part of the deltoid (figs. 1, 6, 7, & 13, D") arises from the innermost part of the ventral margin of the coracoid groove of the sternum, just within the origin of the first part of the deltoid. It is inserted into the humerus above the summit of the brachialis anticus, and on the anteroinferior side of the insertion of the first part of the deltoid. It is superficial to part of the subclavius; and its anteroinferior margin is conterminous with the upper border of the most anterior part of the pectoralis. Omo-hyoid. This muscle has been described amongst the others which belong to the hyoid, Subscapularis (fig. 8, Sl & S2). This large muscle consists of two distinct parts. One arises from the whole costal surface of the ossified part of the scapula, between the insertions of the levator clavi- * Meckel, /. c. p. 313. + Meckel. I. c. p. 342. |
