28 
NEIL E. STEVENS 
inch above normal. Quite different conditions prevailed in 1914. 
There was no rain in August after the 21st, only 0.32 inch in Sep- 
tember, and no rain in October until the i6th, when two days' rain 
gave the 3.55 inches of rain recorded. It will be seen then that during 
almost two months from August 21 to October 16 there were only 
two days with appreciable rain and these totaled only 0.32 inch, while 
from August 21 to November i there were only four days with any 
rain. It is of course by no means certain that this extreme drought 
was the cause of the total failure of the numerous cankers of Endothia 
parasitica to develop perithecia. The condition is, however, very 
suggestive, and it seems highly probable that a causal relation exists. 
Observations near Washington, D. C. 
The number of inoculations made near Washington, D. C, is 
much smaller than of those made in Ulster County, New York. The 
data available, however, indicate a similar relation between climate 
and ascospore production. Table XII gives the climatological data 
for the seasons of 1913, 191 4, and 191 5 at Washington, D. C. There 
Table XII 
Monthly 
Climatological 
Data for Three Seasons at 
Washington, 
D. C. 
Temperature 
Precipitation 
Mean 
Summation 
Efficiency 
In Inches 
Days with Over 
.01 Inch 
1913 
May 
64.4 
602 
67 
4.55 
12 
June 
73-0 
815 
91 
I.8I 
10 
July 
78.0 
lOII 
112 
3.24 
II 
August 
74.0 
909 
97 
5.43 
10 
September 
67.0 
676 
75 
2.41 
6 
October 
59-0 
417 
53 
3.37 
12 
48.0 
130 
25 
2.20 
8 
1914 
May 
67.0 
717 
76 
1.72 
5 
June 
73.8 
870 
94 
6.20 
II 
July 
75.9 
960 
106 
2.32 
8 
August 
76.4 
892 
98 
6.00 
II 
66.0 
643 
72 
0.66 
5 
60.0 
481 
56 
1.56 
9 
November 
45.4 
139 
25 
4-49 
4 
Mav 
62.5 
549 
63 
2.18 
10 
June 
70.6 
774 
84 
6.58 
10 
July 
76.1 
973 
i^^5 
3-21 
12 
Aueust 
74.0 
905 
98 
7.00 
15 
