The nerve to the M. latissimus arises from near the middle of the brachial 

 plexus, most of its fibres coming from the 8th cervical (PL I, 48). It 

 passes obliquely across the deep face of the Mm. subscapularis and teres 

 major and is distributed wholly to the latissimus. 



Nerves to the M. teres major (PI. I, 7). There are from i to 3 small nerves 

 supplied to this muscle. They arise from the N. axillaris or rather are 

 branches of it, and pass directly to the muscle, close to its anterior border. 



N. axillaris (PI. I, 46) arises from the 7th and 8th cervical nerves. It 

 passes through the triangular space formed by the Mm. subscapularis, 

 teres major, and the caput longum tricipitis. To demonstrate the distri- 

 bution of the nerve first remove the skin and the panniculus from the 

 lateral or external surface of the scaptdar region. Dissect up the borders 

 of the M. deltoideus and transect it about 15 to 18 cm. from its attachment 

 to the deltoid tuberosity. Careftdly reflect the humeral portion of the 

 muscle in order to expose the N. axillaris which enters the deep face of the 

 muscle directly opposite the above mentioned triangular space (PI. II, 22). 

 Beneath the muscle, the nerve divides into several branches which are 

 distributed as follows: several branches enter the deltoideus; one large 

 branch passes obliquely across the superficial surface of the teres minor 

 (near its humeral end) to the anterior face of the brachium and enters the 

 mastoido-htmieralis several centimeters below (distal to) the point of the 

 shoulder (PI. I, 24) ; another large branch crosses the superficial surface 

 of the caput laterale tricipitis or sometimes, is embedded in the substance 

 of this muscle, and emerges from beneath the posterior border of the M. 

 deltoideus at the level of the deltoid tuberosity where it becomes subcutane- 

 ous (PI. II, 23) ; from here, this subcutaneous branch extends to the antero- 

 intemal aspect of the antebrachium where it breaks up into several cutaneous 

 branches some of which extend nearly to the carpus. One branch of the 

 N. axillaris is distributed to the teres minor. This branch may be readily 

 demonstrated by transecting the muscle, a little proximal to the N. axillaris, 

 and drawing aside the muscle. One or more branches are supplied to 

 the teres major, one branch to the subscapularis and a very small filament 

 to the M. capstdaris. The branches to the subscapidaris and the capsularis 

 may arise from the main nerve trunk either separately or by a common 

 branch. 



Clean up the V. axillaris and the several veins from the pectoral, pannicu- 

 lus, and latissimus muscles also clean up the portion of the V. subscapularis 

 that lies in the space between the Mm. subscapularis and teres major. 

 Demonstrate the axillary l3miph gland (PI. I, 49), which lies on the tendon 



