DEGENERATION AND REGENERATION OF NERVES 67 



such marked degeneration after a prolonged diet of white rice. 

 This being the case, it would then be desirable to know whether 

 regeneration could take place in these fibers without going through 

 that stage termed ^embryonic nerve fiber,' 'Bandfiber' or 'pro- 

 toplasmic band.' For a more complete understanding of the 

 significance of the multiplication of the nuclei of the neurilemma 

 sheath and the embryonic nerve fiber, I sought to determine 

 if degeneration in medullated nerve fibers without multiplication 

 of the nuclei of the neurilemma sheath could be brought abt)ut 

 by any other experimental means; and if so, could regeneration 

 be accomplished in these without the embryonic nerve fiber stage? 

 Further, could it be shown that the increase in the number of 

 nuclei usually observed is due to trauma or inflammatory influ- 

 ences or to an infiltration of phagocytes? And lastly, does the 

 embryonic nerve fiber represent a stage of regeneration or degen- 

 eration? An answer to these questions would manifestly throw 

 additional light upon the significance of the increase in number 

 of nuclei of the sheath of Schwann and of the embryonic nerve 

 fiber. This proved to be a most attractive phase of the investi- 

 gation. 



Atrophic degeneration without multiplication of the nuclei of 

 the sheath of Schwann has been frequently described in certain 

 chronic pathologic conditions lasting many weeks or months. 

 In the present case, however, where globulation and breaking 

 up of the axis cylinder have been observed as early as the nine- 

 teenth day of the white rice diet and where the first evidences 

 of change noted was on the seventh day, the degeneration (tak- 

 ing place in 12 days) can not be said to have anything in common 

 with atrophy. 



It soon became evident on histologic examination that regen- 

 eration does occur in those fibers in which the neuraxis and 

 medullary sheath have broken up. Having failed to find in the 

 degenerated fibers a single embryonic nerve fiber or any marked 

 or definite increase in the number of nuclei of the neurilemma 

 sheath, I next examined nerves from fowls at various periods 

 during regeneration. With this end in view, fowls were killed 

 after having been kept on a regeneration diet for 4, 11, 13, 14, 



