63 



these periods as would be expected from the behavior of the 

 plants at the other stations. 



Before concluding this part of the discussion it is de- 

 sired to call attention to some peculiarities of the plant 

 graphs which cannot be correlated with the climatic data, "^he 

 first of these 's the occurrence of growth rates for some of 

 the oeriods very much higher than tJie climatic data and the 

 assumptions male above would lead us to expect. This condi- 

 tion of afiairs in illustrated by the period beginning July 17 

 for College , the period beginning August 20 for Baltimore, the 

 one beginning July IC for Darlington, the ones beginning 

 June 24, July 8 and July 22 for Coleman, and the periods be- 

 ginning July V and Aug. 4 for Princess Anne. In all of these 

 cases climatic conditions favorable for growth would seem to ob- 

 tain. The climatic values for these periods do not, however, 

 appear to be sufficiently different from other periods showing 

 relatively lower plant values to account for the very high 

 plant growth rates. This behavior of the plants may be ex- 

 plained by the fact that two periods showing the same average 

 intensity of climatic condtions may differ greatly in their 

 plant producing power m account of a different distribution 

 of the high and low values of the intensities of the conditions 

 luring the period. 



In the discussion of the two-week temperature data at- 

 tention was called to the fact that the graph of temperature 

 Values shows two maxima, and that this was corinected with a 

 peculiarity in the behavior of the plants. Th° peculiarity 

 ther'' referred to is that the olants do not, except in the case 

 of the culture at Oakland, respond to the second +-emperature 



