-jir> these ordinate values of the smoothed prowth-tem- 

 perature graphs, were calculated temperature coefficients i 

 svery ten-degree interral by whole degrees, between the lcvest 

 and highest maintained temperature tested for each of the con- 

 secutive 24 hour observations periods represented in tahles 

 IX - XII. To illustrate the method followed, the mean 24-hour 

 growth rate for ^ythiacystis , for the first day after inocula- 

 tion is seen (table IX) to he 0.3 m n for a maintained tempera- 



c o 



ture of 8 , and Z. n m m. for a maintained temperature of 19 c« 



The ratio 3.^ to 0.3 is 12.3 which is the 1" -degree coefficient 



r - o 



(3, ) for the 10-degree interval from 8 to IS c. Wow 



10 



since the value of C£ 10 varies with the maintained temperature, 

 if its fluctuations are to he studied, it is necessary to cal- 

 culate the different values, not for successive 10-degree 



o 

 intervals (as 8 -18, 18°-28 c , 28 -38 C ), but for 10-degree 



ranges beginning with each successive whole degree for which 



data are available (as 8° 7 18°, 9° -19°, l0°-20°, etc) If 



the value just obtained for e°-18 c c he written 8^> 



10 (po. 1B o) = i23 



then referring to table IX we may write Q, (9°-19 ) = 8.4 ; 

 Q 10 (100.20© ) = 6.7 i q 1Q (11°. 21°) = 5.1, etc. 

 ?or convenience of reference aid for convenience in plotting 

 these temperature coefficients for various 10 degree tempera- 

 ture ranges as they are made to shift by one degree intervals, 

 the middle point of each 10-degree range is taken to represent 

 the range itself. us Q 10 for 13° stands for the 10-depree 

 temperature coefficient for the range (8° - 18°) whose midcils 

 point is 13°. 



77 



