352 BOTANICAL GAZETTE [DECEMBER 
consistent with the nature of the seeds in any given case. It is 
possible also that effective sterilization of the seeds before placing 
them in the germinator in some cases would alter the conclusions 
as to optimum temperatures for germination. 
The two lots of petunia seeds tested in 1912 germinated some- 
what less completely with either of the constant temperatures 
20° or 28° than with certain of the alternations of temperatures, 
especially 20°-30° C. The petunia seeds used in the tests which 
were made in 1914, however, germinated as completely with any 
constant temperature from 17.5° to 30° as with the temperature 
alternation 20°-30°C. In these tests the highest percentage of 
germination obtained occurred with the constant temperatures 
25° and 30°. In testing petunia seeds for germination, probably 
the most uniformly good results would be obtained with a constant 
temperature not warmer than 25° or cooler than 22.5°, or with 
the temperature alternation 20°—30° C. 
From 4 to 10 per cent of the sweet pea seeds remained hard 
at the expiration of the germination tests at different temperatures. 
No effect of temperature upon the softening and germination of 
these seeds was noticed. . 
RAPIDITY OF GERMINATION IN ICEBOX.—In the icebox the first 
larkspur seeds germinated during the tenth day, the first poppy 
seeds during the sixth day, and the first snapdragon seeds during 
the twelfth day. With each kind of seeds, the progress of 
germination in the icebox was slow. Four weeks were required 
for a germination test of one lot of larkspur, and three weeks for 
a germination test of the other two lots of larkspur and some of 
the lots of poppy. The snapdragon seeds were kept in the icebox 
over five weeks. At the end of this time germination had prac- 
“tically ceased, but the total percentage of germination (38 per cent) 
was still but little more than one-half as great as 17.5° C. (67 per 
cent). The majority of the snapdragon seeds which germinated 
in the icebox germinated between the twentieth and thirtieth days 
of the test. 
The germination of larkspur no. 250585 began on the eleventh 
day and was complete in twenty days. At the same time no 
seeds of larkspur no. 250500 germinated until the nineteenth day, 
