490 M. J. GREENMAN 



weight (table 3) we note that our operated animal has 369 less 

 fibers than the normal animal, a difference of 16 per cent, the 

 normal number being taken as the standard. 



It is, therefore, evident that the operation causes in this in- 

 stance a loss of about 16 per cent of the medullated fibers in the 

 control nerve. 



If further we compare the grand average of the number of 

 fibers in the control nerve 2022 (table 3) with the estimated 

 normal number 2306, we still find a deficiency of 284 fibers or 

 12.3 per cent. 



It thus appears that there is a substantial deficiency in the 

 number of the medullated nerve fibers in the control nerve of 

 the operated animals. 



Again, if we note the average weights of the different groups 

 at the time of operation and at the time of killing as shown in 

 table 4, we see that the 276-day or oldest animals lost weight, 

 while the two younger groups gained weight between the time 

 of operation and the time of killing. We also observe that at 

 the time of operation the younger the group the less is its aver- 

 age weight, while at the time of killing the younger the group 

 the greater is its average weight, showing that the effects of 

 operation were more profound on the older animals. 



Dunn ('09) found a less number of efferent fibers in the unoper- 

 ated leg of an operated frog, but apparently did not attribute 

 the loss to the treatment the frog had received. So far as I 

 am aware, there are no records in the literature touching the 

 loss of fibers in the intact nerve as a result of an operation. 

 Appreciating the importance of these effects of operation upon 

 the unoperated nerves, experiments have been extended along 

 this line and the results will be presented in a later study. 



NUMBER OF FIBERS IN THE OPERATED NERVE 



We will now pass to the consideration of the relations to be 

 found in the operated peroneal nerve. The data to be discussed 

 are presented in table 3, which gives the number of fibers found 

 on the proximal and the distal sides' of the lesion; the position 



