BY W. J. S. MCKAY. 299 



Insertion. The muscle runs outwards, upwards and pos- 

 terior to be inserted close to the inner condyle of the humerus, 

 and on the distal two-thirds of a ridge which reaches from this 

 condyle to the distal extremity of the pectoro-deltoid ridge. 



Relations. The origin is tendinous and tliin, bub towards 

 the insertion the muscle becomes of considerable bulk. Ventro- 

 anteriorly the coracoid belly of the biceps is closely connected with 

 the muscle, while postero-internally tlie muscle lies clo.se to the 

 costse. 



Origin. (6) M. coraco-brachialis brevis. (Fig, 4, Cb. B.). — 

 This muscle lies deeper than the longiis. It arises from the pos- 

 terior angle and border of the coracoid in common with part of 

 the coraco-brachialis longus. 



Insertion. Running as a wide sheet of muscle upwards 

 and outward.s, it is inserted on the ventrally projecting summit of 

 the greater tuberosity, and into a line leading from thence to the 

 lesser tuberosity, this line bounding distally a broad shallow 

 depression (bicipital groove) on the antero-internal face of the 

 bone between the tuberosities. (Fig. 18, Be. G.). 



Relations. The muscle is hidden from view by the coracoid 

 belly of the biceps, and at its insertion it is related to that part of 

 the epicoraco-humeral inserted on the ridge bounding the bicipital 

 groove. 



Origin, (o) M. epicoraco-bradiialis. (Fig. \, A. Ep. br.). — 

 The muscle arises from the outer half of the dorsal surface of the 

 epicoracoid, and from the adjoining dorsal concave surface of the 

 coracoid. 



Insertion. The muscle runs posterior and outwards, to be 

 inserted on the summit of the lesser tuberosity, close to the inser- 

 tion of the subscapularis. 



Relations. At its origin from the epicoracoid the muscle 

 is related to the insertion of the sterno-coracoideus and costo- 

 coracoideus ; both muscles, however, lying in a plane dorsal to 

 this muscle. At its origin from the coracoid it is closely related 

 to the coraco-brachialis brevis. 



