132 JOUKNAL OF ENTOMOLOGY AND ZOOLOGY 



Copper sulfate, nearly saturated solution. Used as a fixer. 

 Fibrils well fixed, pink; cells also well preserved; light blue nuclei, 

 darker cell body; a line of deep blue surrounds the nuclei in some. 

 Other cells have a blue spot in the center. There is some indica- 

 tion of tigroid substance in the cell body. 



Pepsin, sat. aq. sol. after fixation. In cells where the fluid has 

 apparently not acted long, vesicular nucleus, cell body deep blue, 

 nucleus uniformly light, outer processes of all pink. Cells in some 

 places a uniform blue, not clearly marked. In another specimen, 

 all parts are a deep blue, no details, fibrils compact but with some 

 indications of a very fine reticulum. 



Direct action of pepsin, deep blue, cells not evident, but holes 

 remain where they were. No details. 



In comparison with the action of reagents given above and by 

 other methods, a study was made of the fresh ganglia taken directly 

 from the animals and studied in normal salt. Intravitam stains 

 were also tried. Details in the cells were not clearly made out by 

 those methods, but some conditions were determined in the fibers 

 and fibrils. 



Points Suggested by the Experiments 



1. In many cases the results obtained by the use of the reagents 

 were about the same whether the ganglia were first fixed in boiling 

 water or not. 



2. In nearly every experiment when the cells were not com- 

 pletely destroyed the same structures of cell fiber and fibril were 

 evident. The nucleus was usually blue, the cell body blue to pink. 

 Fibrils pink. 



3. Vesicles in nucleus and cell body were produced by several 

 of the reagents. 



4. The fibrils which make up the mass of the cell and large 

 parts of the nerve trunks as well as central portions of the ganglion 

 are quite resistant to reagents of all kinds. They may be found in 

 practically all of the specimens, although they seem to be differently 

 disposed in various preparations. 



