1915] 



ROSE— DEL A YED GERM IN A TION 



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 (9) 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 (sS°C.): 

 (a) in wet sand, (b) in weak solutions of hydrochloric acid, (c) in 

 distilled water. 



3. Tests were made 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. 



Germination of conifer seeds, untreated and after storage in wet sand 

 at 3-5° C; percentage germinating after one month in germinator 



The results given in the table show that germination was 

 definitely increased by cold wet storage for four kinds of conifers. 



