MUSCLES OF THE TIU'SK. 233 



with the skin, which adheres intimately to it by means of a dense cellular 

 . and with the sterno-humeralis, which covers its anterior border. 

 Ily it- deep face, with the two jK>rtions of the deep pectoral, the coraco- 

 nulialis (flexor brachii), and the long extensor of the fore-arm; it 

 responds. l>y lliis face, to the antibrachial apoueurosis and the sub- 

 cutaneous vein of the fore-arm, which it maintains applied against that 

 aponeurosis. 



Ai-linn. It is an adductor of the anterior limb, and a tensor of the 

 antihrachial aponeurosis. 



2. Deep Pectoral. (Figs. 114, 11, 13; 115, 1.) 

 S "iiym. The pectoral is parvus of Man. 



Volume Situation Composition. An enormous muscle, situated be- 

 neath the thorax, and composed, like the preceding, of two perfectly distinct 

 portions, described by Girard as two muscles, and designated by him as the 

 .-/' ;;/-//</, nii-iig and stcrno-prcscapularis. 



.\. M-KKXO-TROCHINEUS. Pectoralis magnus of (Percivall, Rigot, and) 

 Bourgelat. (The great utemo-huineralis of Leyh.) 



Vlnme Extent. This muscle, the largest of the two, offers a con- 

 siderable volume. Extending from the ninth or tenth, rib to the upper 

 mity of the arm, it at first lies beneath and against the abdomen, then 

 ath the chest, and at last is comprised between the walls of the latter 

 cavity, and the internal face of the anterior limb. 



/'"////. It is thin and flat above and below in its posterior third, thicker 

 ami depressed from side to side in its middle third, and narrow and pris- 

 matic in its anterior third. Its general form may be compared to that of a 

 somewhat irregular triangle, elongated from before to behind, which would 

 have, a very short posterior border, a longer internal or inferior border, and 

 an ( xterual or superior still more extensive. 



StfiK-tin-i'. It is entirely composed of thick, parallel, fleshy fasciculi, all 

 of \\hich leave the posterior or internal border of the muscle to gain its 

 narrow or anterior extremity. These fasciculi, as they approach the superior 

 border, become longer, and those which proceed from the posterior border com- 

 mence by ajioneurotic fibres. Uufrequciit intersections of fibrous tissue 



to\\;inl> the. anterior extremity of the muscle. 



Attiii-luiifiito. It originates: 1, From the tunica abdominalis bytheapo- 

 neunitic fasciculi of its posterior border ; 2, By its internal border, from the 

 rior two-thirds of the. inferior bonier of the sternum. It terminates, by 

 its anterior extremity, on the internal tubercle at the head of the humerus, 

 the tendon i,f origin of the coraeo-humeralis, and the fascia enveloping the 

 coraco-radialis. Through the medium of this fascia, it is inserted into the 

 nal lip of the bicipital groove formed by the great trochanti r. and is 

 1 t<> the two terminal branches of the supraspiuatus muscles. (See 

 111. 12.) 



'mi*. Its deep face, which is successively superior and internal, 

 covers the external oblique and the straight muscle of the abdomen, the 

 erratus magnus, costo sternal is, and stcruo-prcscapularis, as well as some 

 :M ular nerves; all these relations are maintained by means of a 

 and abundant cellular tissue. Its superior face, which alt< mat. ly 

 vmvards and outwards, responds: to the skin, from which it is 

 separated by a slight cellulo-fibrous fascia; to the sterno-apoiieurotit a-- ; 

 and to the muscles, vessels, and nerves of the inner aspic t of the arm, through 



