127 
the Egyptian Cotton-plant . 
Giza, 1909, it is interesting to note that the curve has been cut off rather 
sharply after July 30. It is significant to note that according to W. L. Balls 
the yield at Giza in 1909 was cut down very early by the rising water table 
due to an exceptionally early and high Nile flood. 
Very few, if any, of the Bahtim curves so far examined show this feature } 
and there is reason to believe from other evidence that the water table plays 
Fig. 7. Smoothed flowering curves (flowers per plant per day) of the Bahtim dates of 
sowing experiment, 1920. PM, Pilion sown March 1. PA, Pilion sown April 1. SM, Sakel- 
laridis sown March 1. SA, Sakellaridis sown April 1. 
a relatively unimportant part in the Bahtim experiments. It ought to be 
possible by this method of analysis of the summation curves to indicate 
reasonably sharply the influence of any specially marked disturbing factor 
on the yield of the plant. 
The possibility of the application of a series of these curves to an 
agricultural experiment is illustrated in Figs. 6 and 7, which give the 
flowering curves calculated from the data of the dates of sowing experiment 
at Bahtim in 1920. 
