| OCR Text |
Show 76 MR. A. SANDERS ON THE [Jan. 6, backward and ventrad to the base of the tuberosity of the humerus, extending beyond the insertion of the last. Fig. 2. Muscles on the inner aspect of the arm. X 3. The supraspinatus corresponds to the muscle named by Mr. Mivart epicoraco-humeral in Iguana, and subclavius in Chamaleon parsonii. The infraspinatus does not appear to be represented in Iguana, but might correspond to one of the suprascapular in Chamaleon. Teres minor corresponds to infraspinatus in Iguana, but is not found in Chamaleon. In my two former papers I took the liberty of differing from Mr. Mivart in the interpretation of these three muscles, and explained my reasons for so doing ; but perhaps it will save the trouble of referring to those memoirs, if I briefly recapitulate those reasons in the present place. First, as to the insertions, they are all inserted on the outer side of the humerus, or close to it, at a point which corresponds to the greater tuberosity ; these insertions occur in the following order, viz. the supraspinatus nearest the head of the bone, the infraspinatus next, and the teres minor* furthest off-an arrangement which closely agrees with that found in the human subject. Next, with regard to the origins of these muscles : supraspinatus arises from the coracoid bone together * In a lizard, however, which I have recently dissected, a species of the subgenus Tropidolopisma, this muscle ends in a tendon which winds round the humerus to be inserted close to the head of the bone, quite on the inner side, being covered by the internal head of the triceps. |
