M. CLAVO-DELTOIDBVS. 231 



form the direct continuation of the latissimus, while the remainder 

 is chiefly muscular. The cephalic surface jjresents the opposite 

 -appearance, being muscular as to its proximal fifth. In general, it 

 is as if the shorter tendon of the teres were applied upon the longer 

 tendon of the latissimus in such a way that the distal border of the 

 latter shows upon the caudal surface of the joint tendon, while the 

 proximal border of the former shows upon the cephalic surface. 



The area of attachment (Fig. 71, 72) is about one seventh of the 

 length of the entire humerus, and forms an elongated fossa upon 

 the caudal surface, near the ventral border ; its proximal end is 

 opposite the distal end of the area of insertion of the short head of 

 the coracoideus. 



M. CLAVO-DELTOIDEUS. 



§ 637. Synonymy. — The clavicular portion of the human deltoideits, G., A, 4M ; Q., 

 A, 1, 199 ; " delta ■clamculaire," S.-D., A, II, 351 ; "portion du mastoido-humeral," Ch., A, 

 209 ; portion of the mastoido-humeral, Ch. (Fl.), A, 197 ; portion of the cephalo-humeral, 

 Miv.. B, 147 ; Wood, 9, 101. 



Figures. — Eotal aspect, clavicular end (66) ; ectal aspect of whole (73, right side) ; 

 ental aspect of antebrachial part (73, left side). 



Posture. — Latericumbent, the venter toward the dissector. Se- 

 cure the arm caudiducted so as to stretch the muscles upon the 

 ventral aspect of the brachium and shoulder. 



Exposure. — The proximal end of the muscle was exposed dur- 

 ing the exposure of the clavo-trapezius. Connect the vertebro-pre- 

 stemal incision made in exposing the trapezii with the dorsal border 

 of the antebrachium, at the junction of the proximal and middle 

 thirds, by an incision along the ventral border of the brachium and 

 passing caudad of the elbow. Keflect both edges of the skin for 

 2-3 cm. near the shoulder, and for 1-2 cm. near the elbow. 



G-eneral Description. — Tseniate ; along the ventral aspect of 

 the brachium, from the clamcle to the ulna. 



Dissection. — Draw the clavicular portions of the clavo-trapezius 

 and clam-mastoideus away from the body so as to expose the more 

 or less distinct bands— hardly deserving the name of ligaments— 

 which pass from the ends of the clavicle to the shoulder and neck. 

 In a subsequent dissection of the parts these connections may be 

 studied in detail before division. Divide them and draw the same 

 muscles cephalad so as to render tense the clavo-deltoideus, and 

 indicate the general position and direction of its borders. 



The caudal border begins at the sternal end of the clavicle, 



