BRACHIAL PLEXUS OF NERVES IN MAN 311 



funiculi mg^y have been broken, but no evidence of this was found 

 by naked eye examination. 



The 7nedial fasciculus of the plexus 



The medial fasciculus of the plexus is formed of the ventral 

 branch of the caudal trunk in 166 or in 94.85 per cent of the 175 

 plexuses (fig. 1). In 5 of these there is a branch from the seventh 

 cervical nerve to the medial fasciculus (fig. 5) . 



In 6 specimens the medial fasciculus is formed of the ventral 

 branch of the eighth cervical joined with the whole of the plexus 

 part of the first thoracic which has in these no dorsal branch; 

 it takes the place of the caudal trunk (fig. 26). In one of these 

 the medial fasciculus receives a branch from the seventh cervical 

 nerve (fig. 4). 



In 2 others the medial fasciculus is formed b}^ the union of the 

 ventral branches of the eighth cervical and first thoracic nerves. 

 It is not impossible that there would be others arranged like the 

 above if more of the connective tissue could have been safely 

 removed. 



There is one other specimen in which the medial fasciculus 

 and the caudal trunk are identical. The medial head of the 

 median in this gives off a dorsal branch to the dorsal fasciculus 

 which is usually given off from the caudal trunk. 



The posterior fasciculus of the plexus 



The posterior or dorsal fasciculus of the plexus is formed of 

 the dorsal branches of the cephalic, intermediate and caudal 

 trunks, or of dorsal branches from the nerves making up these 

 trunks. It is seldom possible to trace the branches proximally 

 to the spinal nerves. These dorsal branches do not always com- 

 bine in the same way. 



In 10 plexuses (fig. 25) the dorsal branches of all these trunks 

 meet at about the same point to form the posterior fasciculus 

 (fig. 1). 



In 86 plexuses the dorsal branches of the cephalic and inter- 

 mediate trunks join to form a cephalodorsal cord which is joined 



