THE NERVOUS CYTOLOGY OF PERIPLANETA ORIENTALIS. 351 



XIV. CELLS SUBJECTED TO PROLONGED FARADIZATION. 



i. Technique. — A roach, placed in a chamber devised for the purpose, was sub- 

 jected to a strong Faradaic current at frequent intervals for three hours. At the 

 end of this time there was almost no reaction to a current that could scarcely be borne 

 through the hand. The ganglia were then removed, and fixed, one in graded forma- 

 lin, one in picrof ormalin, and the third teased and fixed in formalin vapor as already 

 described. 



2. Observations. — In the graded formalin preparations (PL XXVIII, Figs. 46, 

 47) many of the nuclear membranes were slightly wrinkled and uneven. This change 

 was so moderate in degree as not to warrant the statement that it constituted a 

 definite pathological change. The nucleus itself appeared as in normal material. 

 The great majority of the cell-bodies, however, showed a considerable pallor, due 

 to a marked diminution of the deposit of the deeply staining substance. The network 

 itself stood out very sharply and presented a somewhat flaccid appearance. A very 

 few cells, especially along the lateral edges of the ganglion, took a very intense blue 

 stain, owing to an excess of the chromophilic deposit. Such cells could be found 

 in normal tissue, but their appearance was so strikingly in contrast with that of the 

 majority of the cells just described that they have been mentioned in this connec- 

 tion. The picroformalin preparations showed the usual perinuclear condensation 

 and peripheral distortion, thus obscuring the appearances occurring after graded 

 formalin fixation. The teased specimens, however, corroborated the observations 

 above described. The network was very much clearer than in normal cells teased 

 and fixed in the same way, and it exhibited also the flaccid appearance. 



XV. CELLS FROM ROACHES POISONED BY STRYCHNINE. 



i. Technique. — A roach was fed on equal parts of 1% strychnine nitrate solu- 

 tion and molasses. Considerable twitching of the legs was observed. Three and 

 one-half hours later the animal was moribund. The alimentary tract contained 

 molasses. The ganglia were removed at once and fixed by graded formalin, picro- 

 formalin, and one was teased and fixed in formalin vapor as in the other experiments. 



2. Observations. — The graded formalin preparations and the teased cells showed 

 the changes just described for Faradized cells, but in a much less pronounced degree, 

 While I believe there is no question of the results obtained with Faradization, I should 

 be quite unwilling to set down the changes after strychnine as unquestionably demon- 



