DEGENERATION AND REGENERATION OF NERVES 83 



alcohol and in Bensley's chrom-sublimate solution for carmine 

 staining. 



It had been previously shown by me ('12), that, in degener- 

 ation in the rice-fed fowls at time of paralysis, there is just as 

 large a percentage of fibers showing advanced degeneration in 

 the sciatic as in its peripheral rami. In regeneration, then, there 

 should be, in the earlier stages, a greater percentage of fibers 

 containing no axis cylinder in the peripheral branches than in 

 the sciatic itself; pro\'ided of course, the new axis cylinder is 

 the result of an outgrowth. To determine this, segments of the 

 sciatic and its peripheral rami were cut out in the above series 

 of regenerating fowls for comparison with each other and with 

 the sciatic of the other side at a later date. 



The first indication of a regeneration of the axis cylinder was 

 obtained from fowl No. 54 which developed marked leg paralysis 

 on March 4, 1912. The animal was placed on the regeneration 

 diet on March 7. By ]\Iay 3, all signs of neuritis had disappeared 

 and complete use of the legs had been regained. On this day, 

 on the left side, segments of the nerve were cut out from the 

 upper part of the thigh, and from near the foot. An examination 

 of transverse sections of these two pieces revealed a greater pro- 

 portion of medullated fibers devoid of axis cylinder in the periph- 

 eral segment than in the segment from the thigh. Out of 742 

 fibers in the peripheral portion, the axis cylinder was wanting 

 in 11; in 1365 fibers (counted at random) in the proximal por- 

 tion, the axis C3^1inder was wanting in 9. The fowl was killed 

 114 days later, on August 25. Transverse sections of the sciatic 

 of the opposite side on this date, revealed an axis cylinder in 

 practically every fiber. In 5788 fibers the axis cyhnder was 

 wanting in 8. Sunilar data were obtained from the nerves of 

 other rice-fed fowls, No. 52, No. 57 and No. 64. However, as 

 degenerated fibers may not be evenly distributed throughout 

 the sciatic, one peripheral nerve may contam a larger percentage 

 of degenerated fibers than its neighbor and relatively more than 

 the sciatic of which it is a branch. As misleading results might 

 thus be obtained, this method of comparison was not prosecuted 

 further. 



