320 ABRAM T. KERR 



There are 33 plexuses of the E type, 18 of these are on both 

 sides of the body, or in 54.54 per cent. The remaining 15 

 plexuses of the E type are 8 on the right and 7 on the left. Those 

 on the right are associated in 6 cases with B, in 1 with D, and in 

 1 with F type of plexus on the left. In the 7 instances in which 

 the E type is on the left, the B type is on the right. 



Of the 10 plexuses of the F type 6 are found on both sides or 

 60 per cent. The other 4 cases are associated with B type on 

 the right in 3 and E type on the right in 1. 



Symmetry occurs only in the B, E and F types of plexus, which 

 are the most common and typical plexuses for each of the three 

 groups, 1, 2 and 3. This is suggestive that the A, C and D types 

 of plexus are anomalous and ma}^ have no great significance. 

 There is no plexus of the G type in the bodies where the records 

 for both sides are complete. It will be noted that when the A, 

 C or D type of plexus occurs qn one side it is associated with a 

 plexus in the same group on the other side, A and B, B and C, 

 E and D. 



Slightly over 71 per cent of the B type plexuses are symmetri- 

 cal, 60 per cent of the F type and a little over 54 per cent of the 

 E type. That is, in the most cephalic group of plexuses sym- 

 metry occurs most often and in the intermediate group least 

 often. 



Among the 24 bodies with an asymmetrical arrangement of 

 the plexus, a more cephalic type is found upon the right side in 

 15 or 62.50 per cent and a more caudal type in 9 or 37.50 per 

 cent. 



Among the 24 bodies with asymmetrical plexuses, group 1 is 

 found on one side and group 2 on the other in 13 instances or 

 54.16 per cent. In these type B of group 1 is on the right side 

 in 7 and type E of group 2 on the left. In the other 6 cases, the 

 arrangement is reversed. In 3 others or 12.50 per cent group 1 

 is on the right side and group 3 on the left. In these type B of 

 group 1 is on the right and type F of group 3 on the left. In an- 

 other instance group 2 is on one side and group 3 on the other. 

 In this case type E of group 2 is on the right and type F of group 

 3 on the left. The remaining 7 bodies were classed as asym- 



