340 BOTANICAL GAZETTE [DECEMBER 
It may be convenient in seed testing laboratories to use alternat- 
ing temperatures in conducting germination tests of some of the 
kinds of seeds considered, in order to conform to methods estab- 
lished for use in testing the germination of other kinds of seeds. 
This matter will be discussed later. 
GERMINATING CAPACITY 
Twelve of the species studied belong in group 1. Table I 
shows the results, so far as total germination is concerned, of the 
TABLE I 
GERMINATION OF FLOWER SEEDS OF GROUP I 
AVERAGE PERCENTAGES OF GERMINATION 
First series of tests* Second series of tests* 
SEEDS fe 
oo . 
N °. se ° ° N 17:5 
oe 20°30" as et Kes 37° 28° 1 30° ot rer pee 5° 25° | 30° 
lots =e lots 20°-30° 
Balsam......... t | 98 to.g9 | 98 | 98 | 08 3 | 94 | 94 to 98 | 97 | 98 
Cal. poppy...... 2 | 62 to 70 | 62} 62| 59 |....] 1 | 72 | 77 to 85 | 74 | 68 
Candytuft...... 2 | 74to 80 | 83 | 70 | 74 | 62 | 5 | 79 | 78 to 80 | 78 | 76 
Cosmos of 1 BO10 88 10...) BOs ivi e.t (2 1 7 to 92 
ce 1 | ot to 98 | 88 | 88 | 84 2 | 76 | 78 to 80 | 74 | 78 
Marigold....... THONGS te RAR A 8 vowed, cuit eo BOO OF to ag | O21 oP 
Mignonette. .. . . 2 | 68to 71 | 72 | 66 | 62 3 | 73 | 66 to 71 | 65 | OF 
Petunia...,.:.... 2 | 67 to.74 | 64 1 56:1 70 |... 2| 76 | 71 to 76 | 79 | 80 
oe rs ces t | 90 to 96 | 90 | 92 | go j....| 7 | 89 | 88 to ox | 87 | 87 
Portuistac (5273: I | 86 to 94 | 83 | 90 | 86 | 87 | 1x | 71 | 74 to 80 | 75 | 7 
Sweet pea....... aS GS OG seiabidcchacrlecs de 9 DBE | R410 OE Pe 
i SE I | 90 to 94 | 96 | or | oF 2| 79 | 79 to 85 | 78 | 74 
* The two series of tests were entirely distinct, no lot of seed d in both series. 
experiments with this group. Each of the twelve species germi- 
nated about equally well at any constant temperatures from 75° 
to 22.5°C., and with the temperature alternations 20°-28°, 20°-30°, 
20°-31°, and 20°—32° C, 
Seeds of balsam, candytuft, cypress, marigold, mignonette, 
petunia, pink, sweet pea, and zinnia germinated as completely at 
15°C. as at warmer temperatures. Seeds of balsam, candytutt, 
cosmos, cypress, petunia, pink, portulaca, sweet pea, and zinnia 
germinated as completely at some or all of the constant tempera- 
