REGENERATION OF PERIPHERAL NERVES 505 



From this summary of axis values, we observe that the axes 

 in all controls of operated animals have been reduced below that 

 of a normal fiber, the average for the three animals being 44.3 

 per cent, the percentage of sheath being correspondingly increased. 



In examining the percentage relations of the operated nerves 

 as shown in table 12, it is evident that in the loss in size of fibers 

 of operated nerves the reduction in the percentage of axis is 

 more marked in the animals which are younger and which have 

 lived longer periods since the operation as nos. 114 and 154. 

 This would accord with Dunn's observations ('12). 



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Ihiddle 



hormal Control Ojieraled 



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L 



esion 



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JJislal 

 Clveroje areas of lajyest nerve fihrs 



Figure 3 



The control nerve of no. 106 varies less in its axis-sheath rela- 

 tion from the normal than the control nerve of no. 114, a younger 

 animal. It will be noted also that the deviation from normal re- 

 lations in the distal ends of operated nerves is less marked than 

 in the proximal ends, but the distal ends are newly formed while 

 the proximal ends are simply showing modifications. The greater 

 reduction in percentage relation of the axis in the proximal seg- 

 ments of operated nerves as compared with the relation in the 



