BRACHIAL PLEXUS OF NERVES IN MAN 287 



distinguish, in the embalmed bodies, light mulattoes from dark 

 whites, and in any case, it -was quite impossible to tell whether 

 the colored subjects were pure bloods or were a mixture of negro 

 and white. It is probable that in a great proportion of the cases 

 they were not full blooded negroes. It must be remembered also 

 that the so-called American negroes came from tribes or races 

 of African negroes. In the white bodies, likewise, undoubtedly 

 several and mixed nationalities were represented. 



In this paper the number of plexuses and not the number of 

 bodies is given, since not infrequently the dissection or record of 

 one side of the body only was complete or suitable for scientific 

 purposes. In the cases where satisfactory records of both sides 

 were obtained the question of symmetry and asymmetry has been 

 considered in a separate section. 



A preliminary statement of the results of the part of this 

 investigation dealing with the formation of the brachial plexus 

 was presented at the 21st session of the American Association 

 of Anatomists in December, 1906, and a synopsis of the findings 

 was published in the American Journal of Anatomy (Kerr '07). 

 A preliminary account of the findings in regard to the subscapular 

 group of nerves was presented at the 23rd session of the American 

 Association of Anatomists in January, 1908, but no record of 

 these statistics has been published. 



Much credit for the success of the undertaking is due not only 

 to the students for their careful dissections and records but also 

 to the instructors in charge of the dissection for their interest 

 and cooperation. 



I undertook this work at the suggestion of Dr. F. P. Mall, 

 to whom I am greatly indebted for many valuable suggestions. 

 To Dr. C. R. Bardeen I am likewise indebted for much advice 

 and help. I also wish to express my appreciation for the many 

 courtesies extended by Dr. R. G. Harrison. My thanks are due 

 to Drs. Bardeen and Elting for permission to use the records 

 verified by them. 



