934 Journal of Agricultural Research voi. xxm. No. i* 
during the following two weeks, although the* mean temperature was 
slightly lower, but the weather was less cloudy with one rain on August 
25. During the first week in September the growth became almost 
negligible, amounting to only 0.6 inch, and further records were not at¬ 
tempted in view of the difficulty of detecting small differences in the height 
of the stalks. 
A diagram showing the weekly rate of plant growth for the borders 
of each series is given in figure 2. It can be seen that at the end of the 
