304 ABRAM T. KERR 



often join to form new nerve bundles which also usually divide 

 and join again with other branches, and this may be repeated 

 again and again. Where two nerves join, as in a plexus, there is 

 not only a mixing of the nerve bundles of the two but a direct 

 union of the funiculi so that wlien a funiculus from one has 

 joined a funiculus from the other, the newly formed bundle 

 surrounded by perineurium contains a mixed group of fibers 

 from both. There may be a dozen or more bundles in a nerve 

 bound together and surrounded by epineurium. The funiculi 

 vary greatly in size, from minute threads to good-sized bundles. 

 If all the epineurium could be dissected away, it would not be 

 difficult to see how the funiculi branched and how the branches 

 were joined together again. This can be done only with great 

 difficulty if at all in the majority of embalmed bodies. In only 

 a few instances, in selected cases, have I, by means of ordinary 

 dissection been able to remove most of the epineurium and to 

 trace the funiculi to any extent through a plexus. I have found 

 that even with the greatest care in making such a dissection there 

 were many places in which it was impossible not to break some 

 of the fine connecting fascicles. Some of these connecting bun- 

 dles are so small that it is difficult or absolutely impossible to dis- 

 tinguish them from the connective tissue. I have always felt 

 much doubt as to whether I might ifot have broken without 

 knowing it many of the minute bundles that pass from one funi- 

 culus to another. I have, therefore, not included the results of ' 

 any such dissection in my series. Paterson ('96) also feels doubt 

 of his ability to make such dissections, and he says "by anatomi- 

 cal methods it is impossible to separate the fibers of one spinal 

 nerve from its neighbor." 



In all of the cases included in this report the dissection has 

 been carried only so far as seemed safe and only so much of the 

 connective tissue has been removed as was possible without 

 danger of tearing the nerve bundles. It was thought best not 

 to attempt to remove all of the peripheral epineurium in an}^ of 

 the cases. 



To make out the distribution of the fibers of a given spinal 

 nerve in the branches of the brachial plexus it would be necesary 



