290 
Francis Darwin. 
readings, while Nos. 147, 148, 149, of 1917 are earlier than the 
1919 readings. And for the 23 weeks ending June 9th, 1917, and 
also for the 24th and 25th weeks, the 1917 temperatures are 
markedly higher than the corresponding weeks in 1919. 
The general result for 1917 from No. 150 to the end of the 
curve is that the flowerings are somewhat later than in 1919, but 
afterwards become equal to or earlier than the readings for the last 
named year. And this in spite of the cold weather in 1917 from 
June 30th to July 14th. 
1918. With regard to 1918 the general impression is that for 
Nos. 1 to 5, inclusive, the 1919 flowerings are earlier than those 
of 1918. And the 1918 temperature deviations for the first three 
weeks of the year are—S'O, 1 —2-5,—0-1 ; the same period for 1919 
showing + deviations. But from No. 6 onwards the 1918 flowerings 
are clearly earlier than those of 1919. And the 1919 temperatures 
from the week ending January 25, to that ending February 15, are 
markedly below normal, the corresponding temperatures for 1918 
being strikingly above the average. The higher temperature for 1918 
(except for a fortnight of normal temperatures, or slightly below 
normal, in March) continued until the middle of April, the 
corresponding temperatures for 1919 being markedly lower. 
The flowering dates for May, 1918, are only slightly earlier than in 
1919, while the corresponding temperatures are roughly identical. 
The 1918 flowerings in the middle of June are later 
than those of the same plants in 1919, when the 1918 temperatures 
are below, and those of 1919 above, normal. The 1918 plants 
flowering towards the end of June are on the whole later than 
those of 1919, but this does not seem explicable as a result of 
temperature. 
In the middle and end of July occurs a period when the 1918 
plants flowered earlier than those of 1919. The temperatures were 
at this period often below the normal in 1918 and in 1919, though 
more strikingly so in 1919. 
1919. It is unnecessary to enter into detail on the 1919 
flowerings, which are intermediate between those of 1917 and 1918. 
But since, in the graphic representation of the dates of flowering, 
the continuous line of the 1919 flowerings serves as a standard of 
comparisons with the scattered readings of 1917 and 1918, I have 
thought it best to give some details which are not given for the 
1 That is as above explained 5-6 below normal. 
