217 



The Relation of Race to the Position of the Lumbo- 

 sacral Plexus. 



This also is shown in tables 2—8, under "b". It will readily be 

 noted that the anteriorly placed plexuses are decidedly more frequently 

 met with in white subjects, the more posteriorly placed plexuses in 

 negro subjects. One has to be cautious about drawing too great 

 deductions from these figures, however. It must be remembered that 

 EiSLER found that 19 out of 127 (nearly 15 %) of the plexuses 

 examined by him were of the posterior types. Yet he presumably 

 examined plexuses derived from white subjects. 



Influence of sex in the negro and in the white bodies may 

 be seen in the following text -table. It will be noted that in the 

 female white bodies examined the variation in type of plexus was 

 slight. The variation in the male white bodies was about equal in 

 extent to that seen in the female negro bodies. The greatest variation 

 was found in the male negro bodies. 



The Relation of the Skeleton to the Position of the 

 Lumbo-Sacral Plexus, 

 During the first three years of this investigation note was made 

 of the skeletal conditions only occasionally on the appearance of 

 rather unusual conditions, as for instance, six lumbar vertebrae. 

 During the last two years, however, careful note has been taken of 

 the skeletal conditions in every subject. The results are interesting. 

 Variations in the vertebral column is much more frequent than one 

 would expect. The most frequent variations from the "normal", as 

 this is described in practically all the text books, are exhibited in 

 a shortening of the vertebral column. In its simplest form this is 

 marked by a short twelfth rib, an unattached tenth rib and by changes 



