INFLUENCE OF CERTAIN CLIMATIC FACTORS 
23 
D. C, at Woodstock, Md., Van Bibber, Md., and Wilmington, Del., 
and they were developed during the period between December 26 and 
February 15 at Washington Junction, Md. They were also produced 
in small number at an elevation of 1,000 feet on Overlook Mountain 
between October i and May 2. On the other hand, perithecia have 
been produced in mid-summer at all stations from Concord, N. H., 
to Vienna, Va. Perithecia were not produced during the winter or 
spring north of Hartford, Conn., and low temperature may in this 
case have been a limiting factor. Certainly perithecia are developed 
through a considerable range of temperature. 
Table IX 
Monthly Temperature Efficiency Indices for Various Localities 
Char- 
lottes- 
ville, 
Va. 
Wash- 
ington, 
D. C. 
Fred- 
erick, 
Md. 
Wood- 
stock, 
Md. 
Wil- 
ming- 
ton, 
Del. 
Hart- 
ford, 
Conn. 
Mohonk 
Lake, 
N. Y. 
Am- 
herst, 
Mass. 
Wil- 
liams- 
town, 
Mass. 
Con- 
cord, 
N. H. 
I9I4 
May 
85 
76 
75 
73 
28 
June 
89 
94 
96 
93 
95 
71 
66 
66 
63 
60 
July 
107 
106 
103 
lOI 
106 
82 
75 
79 
75 
75 
August 
117 
98 
102 
103 
109 
87 
79 
82 
74 
73 
September. . . 
76 
72 
67 
68 
79 
65 
65 
58 
51 
57 
October 
57 
56 
52 
57 
61 
49 
46 
43 
38 
37 
November . . . 
28 
25 
22 
22 
27 
15 
10 
9 
7 
6 
December . . . 
4 
6 
5 
7 
5 
3 
4 
I 
4 
0 
1915 
January 
3 
5 
3 
5 
4 
3 
0 
0 
I 
0 
February .... 
10 
9 
4 
6 
10 
3 
0 
0 
I 
0 
March 
6 
I 
3 
2 
5 
2 
0 
0 
0 
0 
April 
61 
56 
55 
52 
52 
36 
39 
36 
33 
29 
May 
63 
61 
62 
47 
44 
45 
42 
39 
June 
84 
77 
80 
68 
63 
65 
64 
58 
July 
105 
98 
no 
86 
77 
82 
76 
77 
August 
98 
95 
100 
80 
71 
76 
67 
71 
It has been rather generally believed that low temperature was a 
determining factor in the production of ascospores by pyrenomycetes 
and ascospores have often been loosely referred to as ''winter spores," 
a term used indeed in connection with Endothia parasitica (8, p. 187). 
That low temperatures are not necessary for the production of asco- 
spores by Endothia parasitica is shown by the fact that they developed 
before September 21, 1915, from inoculations made July 18, 1915, at 
Vienna, Va., during which time no temperature below 54° was re- 
corded, and the mean temperature was well over 70°. That high 
