1915] ROSE—DELAYED GERMINATION 433 
nation temperature of 25°C. The common practice of layering 
various conifer seeds doubtless finds its justification in a shortening 
of the time required for germination. Low temperatures have also 
been used for preserving the vitality of conifer seeds. Haack (12) 
dried seeds so they lost about 2 per cent in weight, then stored them 
in dry, air-tight containers on ice. CLEMENS (g) stored seeds in 
the refrigerator of a brewery in vessels containing sodium car- 
bonate to absorb moisture and carbonic acid. Both investigators 
report that seeds thus stored remained viable longer than those 
kept under ordinary laboratory conditions. 
In order to analyze the situation more carefully, the following 
series of experiments were conducted on seeds of various conifers. 
1. Tests of untreated seeds. 
2. Tests of seeds which had been in cold storage (3-5° C.): 
(a) in wet sand, (0) in weak solutions of hydrochloric acid, (c) in 
distilled water. 
. Tests were jade with seeds which had been injected with 
Weak hydrochloric acid or with water, by exhausting the air from 
them when they were in these liquids, and then restoring the 
pressure to normal. This was repeated at least three times for all 
seeds here spoken of as injected. Table IV summarizes the results 
obtained in series 1 and 2a. 
TABLE IV 
GERMINATION OF CONIFER SEEDS, UNTREATED AND AFTER STORAGE IN WET SAND 
AT oc cs PERCENTAGE GERMINATING AFTER ONE MONTH IN GERMIN ATOR 
a 
DRY STORAGE UNTREATED | COLD WET STORAGE FOR 
2 3 4 
months | months | months 
| 
ae 
month 
KIND OF SEED 
Date of starting germination 
oe 
aS 
Esernitcreeceati 
| 
26 Jan. 26| Avril April 4 ‘April 24|May 30| Feb. 26 |Mar. 25 April 26) May 28 
| 
Cupressus brea aca he 8 | 2 Suge 15 27 | 40 36 
Picea ee ae oT ae es 23 70 Be a 
us a petri Ae es 57 48 27 28 78 Beh 64 
Pinus Strobus.......... 12 10 6 28 34 40 44 50 
The results given in the table show that germination was 
definitely increased by cold wet storage for four kinds of conifers. 
