72 



REACTION OF CELLS 



48-9 C. and at 52-7 C. (Miss H. CHICK, Fig. 18), 

 and the killing of Bacterium coli commune by sunlight 

 (CLARK and GAGE, Fig. 19). In all these figures 

 the time in minutes (/) is taken as abscissa ; the 

 ordinates represent log n, where n is the number of 

 surviving bacteria in one drop of the culture. 



These results are very interesting. In the case 

 of yeast-cells the approximative validity of SCIIUTZ'S 



15 30 



Time 



60 



FIG. 19. 



rule indicates that the products of the fermentation 

 in some way hinder the process. Now it is true 

 that the alcohol produced diminishes the activity of 

 the yeast-cell, but not with such regularity that we 

 might expect SCIIUT/'S rule to hold good. There 

 are also other disturbing agents in this case which 

 act in an opposite direction, for instance the incuba- 

 tion phenomenon. But still both in this complicated 

 case and in that of the killing of red blood-corpuscles 



