14 



LOGARITHMIC ORDER OF DEATH 



lOOV 



TORULA MONOSA 

 AT 50* 



50- 



25 



MOSQUITO LARVAE 



IN Xheptylic acid 



lOOV 



SPORES OF 



B. ANTHRACIS 



IN MERCURIC CHLORIDE 



lOOV 



BACT. AERTRYKE 

 X-RAYED 



Fig. 1. Mortality curves (black blocks) and survivor curves (thin 

 lines) of various organisms dying under the action of various killing 

 agents. Abscissa: time of exposure; ordinate: per cent of survivors. 

 (From data of Boycott, 1920, for tadpoles; of O'Kane, Westgate and 

 Clover, 1934, for mosquito larvae; of Davey, 1917, for flour beetle; of 

 Beamer and Tanner, 1939, for Torula; of Madsen and Nyman, 1907, 

 for B. anthracis; of Wyckoff, 1930, for B. aertryke.) 



