Prentiss, Peripheral Netzvorks. 109 



pletely. In the fresh preparation there was some evidence of 

 the subepithelial network, but after fixation the stain was too 

 faint to demonstrate clearly the difference between degenerate 

 and non-degenerate nerves. I was encouraged, however, to 

 make further attempts. 



Series 2. During the first week in October 1903, twelve 

 frogs were operated upon. Of these three survived twenty-one 

 days and were injected with methylene blue. Again only one 

 palate took the stain well. In this preparation a network of 

 non-medullated fibers was clearly demonstrated, and there was 

 some evidence of it in one of the other preparations. Bethe 

 (:03) has shown that when the peripheral nerves of winter frogs 

 are cut distal to their cells, the neurofibrillae of the axis cylinders 

 lose their affinity for stains after the expiration of from twenty- 

 one to twenty-four days. This he proves to be due to the disap- 

 pearance of the organic substance (Fibrillensaure) which is a con- 

 stituent of all normal neurofibrillae and which, combining with 

 certain dyes gives the primary fibrillar stain of both nerve cells 

 and fibers. The fibrillae lose this acid substance, and refuse to 

 stain long before myelin sheaths of medullated nerves show 

 signs of degeneration In these preparations of the palates in 

 which the nerves have been cut for three weeks, the myelin 

 sheaths had almost completely broken down, showing constric- 

 tions and vacuolations throughout the course of the fibers. This 

 does not agree with results of Bethe and Monkeberg ('99) who 

 found complete degeneration of the medullary sheaths in the 

 frog only after a lapse of 102 days, although the neurofibrillae 

 had lost their specific staining power within three weeks. I 

 therefore conclude that the process of degeneration must either 

 proceed much more rapidly in the nerve fibers of the palate 

 than in those of the sciatic nerve, or that the period of nerve 

 degeneration is much shorter in the autumn than during the 

 winter months. To make sure that degeneration was complete, 

 a third series of frogs was operated upon. 



Seiies J. On November 3rd, 1903, the palatine nerves of 

 six individuals were severed. Three of these frogs were kept 

 alive for thirty-five days and two good preparations of the pal- 



