374 ABRAM T. KERR 



62. The axillary nerve arises as one of the terminal divisions 

 of the plexus in nearly 80 per cent of the cases. In over 9 per 

 cent it arises from the cord formed by the union of the dorsal 

 divisions of the cephalic and intermediate trunks and in the same 

 number of cases from the dorsal division of the cephalic 

 trunk. 



63. In over 46 per cent of the cases the axillary nerve gives 

 off none of the other nerves of the plexus but in over 55 per cent 

 it gives origin to the axillary subscapular nerve. 



64. None of the nerves from the fourth cervical to the first 

 thoracic can be excluded from the axillary nerve in over 53 per 

 cent of the cases and from the fifth cervical to the first thoracic 

 in over 25 per cent. None of the nerves that enter the plexus 

 can be excluded in over 78 per cent of the plexuses. 



65. The subscapular nerve occurs as a single nerve in over 53 

 per cent of the plexuses. There are two nerves in over 40 per 

 cent and three nerves in over 5 per cent of the plexuses. 



66. One of the subscapular nerves arises from the dorsal 

 division of the cephalic trunk of the plexus in over 56 per cent 

 of the cases; from the dorsal division of the intermediate trunk 

 in over 19 per cent and from the posterior fasciculus in over 28 

 per cent. 



67. In over 61 per cent of the cases the fourth cervical nerve 

 may send fibers to the subscapular nerve ; in over 94 per cent the 

 fifth and sixth cervical nerves ; and in over 50 per cent the seventh 

 cervical nerve. 



68. The axillary subscapular nerve arises directly from the 

 posterior fasciculus of the plexus or from the axillary nerve or the 

 radial nerve that arise from the posterior fasciculus in over 74 

 per cent of the cases. It comes from the dorsocephalic cord 

 formed by the union of the dorsal divisions of the cephalic and 

 intermediate trunks in over 13 per cent. 



69. The axillary subscapular nerve arises directly from one 

 of the dorsal divisions of the brachial plexus in over 45 per cent 

 of the cases and from the axillary nerve in over 54 per cent. 



70. None of the nerves of the plexus can be positively excluded 

 from the axillary subscapular in over 72 per cent of the cases. 



