114 Observations on the Habits o/Oscinella frit 



, No. of 

 Rainfall ^Wes 

 in inches ^qq 



n-3 



02 



01 



00 500 - 



Max. Tim p. 

 in shade °F 



~ Min. Temp. 

 ~ on erass °F 



7 17 27 6 16 26 

 July Aug. Sept. 



Chart I. Dotted line = rainfall ; upper broken line = maximum temperature in the shade; 

 lower broken line = minimum temperature on the grass; unbroken line = prevalence 

 curve. 1919. 

 A — 5 = average interval in days required for the production of a new generation. 



