the period beginning May 13 to the period beginning May 28, 

 evaporation rate and sunshine intensity remaining nearly constant; 

 rises again, but only slightly, from the period beginning 

 May 28 to the period beginning June 11 as would be expected 

 from the fact that sunshine decreases considerably, the rate 

 of evaporation decreases and the temperature index rises dur- 

 ing this interval. Prom the period begimning June llto the 

 period beginning June 24 the dry weight graph descends although 

 the temperature index value and light value both rise. This 

 is ptobably due to the high evaporation value, The evapora- 

 tion graph rises in this interval only slightly, however. The 

 temperature index value remains nearly constant from the per- 

 iod beginning June 24to the period beginning Aug. 5 while 

 the plant values behave as follows: from the period beginning 

 June 24 to the period beginning July 8 the plant graph de- 

 scends, while the evaporation graph rises; the rise in the 

 plant graph from the period beginning July 6 to the period 

 beginning July 22 may be related to the decrease in evapo - 

 ration rate; and from the period beginning July 22 to the period 

 beginning Aug, 5 the considerable decrease in the value of dry 

 weight does not seem to be accounted for b^- the climatic av- 

 erages. There is, it is true, a fall in light intensity, during 

 this interval but it is hardly great enough to explain th be- 

 havior of the plant graph. That this culture may have been 

 abnormal is indicated by the fact that the dry weight gr .ph 

 rises from the period beginniAg Aug. 5 to the period beginning 

 Aug, 19 although t e temperature index value for the latter 

 period is very much lower than the temperautre index value 

 fot the former. The period beginning Sept. 2 shows a high 

 relative evaporation rate and a low temperature index value. 



