346 ABRAM T. KERR 



nerve and in 1 by two roots, one from the eighth cervical and 

 one from the first thoracic nerve. 



In 32 instances the medial brachial cutaneous arises from a 

 common branch from which the medial antibrachial cutaneous 

 or the medial anterior thoracic or both of these arise (figs. 6, 

 and 17). In 31 of these, this branch arises from the caudal trunk 

 or the medial fasciculus of the plexus and in the other case from 

 the first thoracic nerve. 



In 29 cases there is more than one nerve that was classed as 

 medial brachial cutaneous, in addition to the cases where a 

 branch from the medial antibrachial cutaneous anastomoses 

 with the intercostobrachial. 



There are 36 of the 166 satisfactory plexuses in which a single 

 medial brachial cutaneous nerve arises directly from the caudal 

 trunk of the plexus (fig. 3). In 23 of these there is an anasto- 

 moses with the intercostobrachial. One of these sends a branch 

 to the medial anterior thoracic nerve, another to the medial 

 antibrachial cutaneous and a third to the radial, while two 

 others receive branches from the medial antibrachial cutaneous 

 nerve. In 13 cases there is no record of communication 

 between the medial brachial cutaneous and the intercostobra- 

 chial. In two of these the medial brachial cutaneous receives 

 a branch- from the medial antibrachial cutaneous and in 2 others 

 there is an anastomosis between a branch of the medial anti- 

 brachial cutaneous and the intercostobrachial nerve. 



There are 6 instances in which the medial brachial cutaneous 

 nerve is single and arises from the caudal trunk of the plexus 

 in combination with some other nerve. In 2 of these it is com- 

 bined with the medial anterior thoracic nerve and in 1 of these 

 it sends a branch to the medial antibrachial cutaneous which 

 anastomoses with the intercostobrachial. In 3 cases it is com- 

 bined with the medial antibrachial cutaneous, in 2 of these anasto- 

 mosing with the intercostobrachial. In the last of the 6 cases it 

 arises from a stem common to it and both of the above mentioned 

 nerves and anastomoses with the intercostobrachial (fig. 27). 



In 56 plexuses the single medial brachial cutaneous nerve arises 

 directly from the medial fasciculus of the plexus. In 23 of these 



