288 



PHYSIOLOGY OF BACTERIA 



This latter type will be explained in the next subchapter as due to a 

 variation in the resistance of the individuals. 



If bacterial cells contained more than one reacting molecule 

 per cell, their survivor curves should show a bulging out above a 

 straight Hne, and not a straight or even a sagging curve. If they 

 had more than one reacting molecule per cell, their death rates should 

 be continuously increasing, and not remain constant or decrease. 



Table 80. — Death Rates for Successive Time Units 



f Computed as fc = -^ log r j 



The pronounced difference in the order of death between bacteria 

 and higher organisms indicates that death in the former is brought 

 about by the change of only one molecule in each cell. 



(e) PHYSIOLOGICAL YOUTH 



Cells of the same strain show a different degree of 

 resistance at different stages of development. The first 

 quantitative observation in this respect was probably 



