52 



LOGARITHMIC ORDER OF DEATH 



15 MINUTES 25 



Fig. 13. Semi-logarithmic plot of the survivor curve obtained vi^ith 

 the alga Chlmnydomonas killed by 0.009% HCl. Abscissa: time of 

 exposure; ordinate: number of survivors on logarithmic scale. (From 

 data of Harvey, 1909.) 



Fig. 14. Semi-logarithmic plot of the survivor curve obtained with 

 the protozoon Colpidiuvi killed by mercury bichloride. (From data of 

 Peters, 1920.) 



