472 SCHULTE, SEI WHALE. 



nerve to the latissimus is derived from the beginning of the circumflex-musculo-spiral trunk. 

 If it gave any branches to the subscapularis I failed to find them. 



The musculo-cutaneous nerve arises from the lateral branch of anastomosis close to its 

 union with the branch of the lower trunk. It crosses the humerus obliquely passing beneath 

 the bicipital ligaments. At the elbow it gives off a branch to the flexor carpi radialis and the 

 radial side of the flexor communis digitorum. Its cutaneous filaments were distributed along 

 the preaxial margin of the flipper. In its muscular supply it is seen to carry fibres which are 

 usually included in the median. The nerve to the coraco-brachialis was given off from its upper 

 portion near its origin. 



The musculo-spiral and circumflex nerves are derived from a common trunk which con- 

 stitutes the posterior cord of the plexus. This lies upon the subscapularis as far as its caudal 

 border, where it" divides. The circumflex turns dorsad in the interval between the teres major, 

 subscapularis and humerus to reach the dorsum of the scapula, where it supplies the deltoid 

 and subdeltoideus. The musculo-spiral passes in its usual position behind the humerus to the 

 preaxial border of the flipper. It supplies the triceps and the extensor digitorum. 



The ulnar nerve arises from the lower cord by a short trunk in common with the communi- 

 cating branch and the internal cutaneous. It passes distal to the interval between the flexor 

 carpi ulnaris and the flexor digitorum to both of which it gives branches. At the wrist it divides 

 into branches which pass down the spaces between the digits and along the ulnar side of the 

 fifth digit. The internal cutaneous nerve was smaller. I succeeded in following it only to the 

 region of the olecranon. 



' The internal anterior thoracic nerves are derived from the lower trunk immediately oppo- 

 site the point where it receives the mesal communicating branch. Some of the fibres from this 

 source form a ridge upon the trunk and are directly traceable to the thoracic nerves, which are 

 largely yet not wholly the continuation of these fibres. They enter the sternocostal portion 

 of the pectoralis on its deep surface. 



The pannicular nerve, lateral cutaneous of English authors, is the largest branch of the 

 brachial plexus and forms the continuation of its lower trunk after it is joined by the mesal com- 

 municating branch. It is directed caudad under cover of the pectoralis, to the abdominal 

 portion of which it distributes small branches, and continues caudad beneath the lateral raphe, 

 breaking up beside the vulva into large branches for the ventral and dorsal divisions of the 

 panniculus, to|both of which throughout its course it supplies numerous smaller twigs. At 

 the caudal border of the axilla it gives off a large branch on its mesal aspect, which dividing in 

 two turns round the latissimus dorsi and is distributed to the dorsal panniculus in the scapular 

 and postscapular regions. 



The lower four cervical nerves and the first thoracic communicate with a stellate ganglion. 

 It is situated 'upon the lateral surface of the rectus anticus, in the triangular space between 

 that muscle and the scalenus in close proximity to the vertebral vessels, which are lateral to it. 

 It measures 6 mm. by 4 mm. x 1 mm. Its branches of distribution upon the subclavian artery 

 and the arteries arising from it are conspicuous for their large size. 



