338 BOTANICAL GAZETTE [DECEMBER 
the temperatures recommended and at other temperatures, and 
has verified these conclusions. Duplicates of one hundred seeds 
each were used in making nearly every germination test. In a 
few tests duplicates of only fifty or seventy-five seeds each were 
available, on account of the small size of the samples used. 
Method and apparatus 
The sweet pea and nasturtium seeds were tested in moist 
canton flannel, using two thicknesses of the flannel under the 
seeds and two thicknesses over them. Balsam, California poppy, 
cosmos, larkspur, marigold, mignonette, pansy, and zinnia seeds 
were tested between moist blotting papers, two thicknesses above 
and two below. Candytuft, cypress, petunia, pink, poppy, portu- 
laca, and snapdragon seeds were tested on top of four thicknesses 
of moist blotting paper. In the tests which were made in 1914 the 
poppy seeds were tested both between moist blotting papers- and 
on top of moist blotting paper. 
All tests were made in standard water-jacketed copper germinat- 
ing chambers, and were continued until no more seeds or only an 
occasional one germinated. The progress of germination was care- 
fully watched, and all germinated seeds were counted and thrown 
away at frequent intervals in the tests which were made in 1912, 
and each day after germination began in the tests which were 
made in 1914. 
The seeds were tested with the use of the constant temperatures 
15°, 17.5°, 20°, 22.5°, 25°, 28°, and 30°C, and with daily alterna- 
tions of temperature between 20° C. as the lower temperature and 
28°, 30°, 31°, 32°, 35°, and 37° as the higher temperatures in the 
different alternations. The temperatures hamed as the higher tem- 
peratures in the alternations are those indicated by thermometers 
inserted in the tops of the chambers, and are 1° or 2°C. higher than 
the highest temperatures reached within the blotters or cloths in 
which the seeds were being tested. The alternations include some 
in which the seeds were kept from four to seven hours daily in a 
chamber which was constantly maintained at the higher tempera- 
tures, and the rest of the day in another chamber at the lower 
temperature; and others in which only one chamber was used, 
