

those of Lehenhauer ( 1914) for the gro7/th of maize ss 

 lings and those of most other students of lif e-p^ccasses -- 

 temperature relations cased en short tame and temperature in- 

 tervals. The graphs published by "Brooks & Cooley^ showing the 

 relations of growth of a number of apple ret fungi to tempera- 

 ture for 5-degree intervals, also suggest the same general 

 type of curve. 



If the curves for the successive 24-hour periods "for 

 each fungus (figs. 2-5) are compared, certain general features 

 may be noted. For every fungus there is a shift of the ap- 

 parent maximum temperature downward (to the left in the graphs) 

 with each successive observation period. Ls shifting is 

 much more pronounced "between the first and second 24-hour per- 

 iods than between any other two consecutive periods, except in 

 case of Phytophthora. For Pythiaeytis the maximum shifts 

 froi-: a>out 36° for the first 24-hour period, tc about 32 for 

 the fifth period ; for Phytophthora the corresponding shift 

 is from about 38 to about 35° , for Diplcdia the maximum 



temperature shifts from about 46 for the first 24hour period 



o 

 to about 35 for the third period . The maximum temperatures 



for Phomopsis a^e more uncertain. 



A similar shifting of the apparent teaperature op f 



is shown for all the fungi excepting Phomopsis. The :- snt 



optimum temperature for Pythracyatis shifts from ^ 27.5 



for the first day to about 24 for the fifth day, the correspond- 



o ° 



ing shift for Phytophthora is from about 34 to about 26 for 



t'. • lame time and -for Diplodia the optimum shifts from about 



c o 



31 for the first day to afcout 27 for the third day. "Rut 



N ^V?rooks, C and Rooley. J.F., Temp ?. -.s k ire relations or apple 



rot fungi. Jour, t . I B j 139 - 153, 191' • 



59" 



