INFLUENCE OF CERTAIN CLIMATIC FACTORS 
15 
decrease in the temperature summations from Charlottesville north- 
ward. A comparison of the curves of growth and temperature 
summation (figs. I and 2) shows that there are some irregularities and 
that the temperature summation falls somewhat more rapidly north- 
ward than does the amount of growth. 
Table VI 
Temperature Summations 
Locality 
Year 
Ending 
Summation 
Percent 
Year 
Ending 
Summation 
Percent 
Charlottesville, Va.. . . 
Apr. 20 
6,412 
100.00 
Washington, D. C. . . . 
22 
5,153 
80.0 
July 28 
4,941 
77.1 
Frederick, Md 
27 
5,005 
78.1 
Woodstock, Md 
27 
5,024 
78.3 
Aug. 9 
4,742 
73.8 
Mohonk Lake, N. Y. . 
May 14 
5,443 
84.9 
10 
5,169 
80.0 
24 
3,623 
56.5 
II 
3,465 
54-0 
15 
3,943 
61.0 
18 
3,779 
590 
Amherst, Mass 
17 
3,584 
55.9 
17 
3,479 
54-3 
Williamstown, Mass. . 
22 
3,017 
47.0 
16 
2,970 
46.3 
Concord, N. H 
18 
3,045 
47.5 
19 
2,924 
45-6 
Temperature Efficiencies 
In calculating temperature efficiencies the Livingstons' method 
was adopted with no change except in the zero point. That is, it was 
assumed that the efficiency doubled with each rise in temperature of 
18° F., since this assumption seems to agree most nearly with the 
work of the numerous investigators who have sought to determine the 
application of the van't Hoff-Arrhenius principle to physiology.^ 
There is, of course, no direct evidence that growth in the case of 
this particular fungus is accelerated by rise in temperature at the 
rate assumed. The calculations were made rather to determine how 
closely the general law would apply to this organism under field con- 
ditions. 
Efficiency was assumed to be unity at 45° F. The writer is however 
inclined to believe now that 47° might be even more accurate. This 
makes the formula for calculating efficiency 
^ -45 
when e = the efficiency and t the daily mean temperature. A table 
was prepared on this basis and used in calculating the temperature 
5 For a brief resume of the literature on this point see 5, p. 356-359. 
