CYTOLOGICAL CHANGES DURING GERMINATION 93 



that there is a sharp break in the RNA rise and shortly after this the synthesis 

 of DNA begins. 



RoBiNOW: Fitz-James has made it very probable by direct chemical de- 

 termination that there is DNA in the Feulgen-positive material which rest- 

 ing spores extrude above the cell surface when they are treated for a few 

 minutes with N/l-N/3 nitric or N/1 hydrochloric acid at room tempera- 

 ture. His experiments made use of the fact that the material which B. cereus 

 spores extrude when they are treated with N/3 nitric acid containing 0.1% 

 potassium permanganate is soluble in low concentrations of sodium acetate 

 in water. Fitz-James showed that the dissolution of the "chromatinic side 

 body" went hand in hand with the gradual loss of DNA from the treated 

 spores and the accumulation of DNA from the treated spores and the ac- 

 cumulation of DNA in the washing fluid. 



Witter: I want to ask Dr. Robinow if the extrusion of chromatin under 

 the influence of hydrochloric acid can be correlated with changes in optical 

 density and also how the ability to react in this way is correlated with the 

 various phases of germination. 



Robinow: My own experience has been only with the affinity of spores 

 for stains. The extrusion response is given only by spores that are refrac- 

 tile and non- staining. Spores that have become transparent and readily 

 stainable after being placed on a suitable nutrient medium no longer ex- 

 trude their chromatin when challenged with nitric or hydrochloric acid at 

 room temperature or at 60°C. 



