288 ■ BOTANICAL GAZETTE [april 



produced seedlings. Two lots of 500 each were selected from the 

 seeds in which the hypocotyl was still inclosed within the endosperm. 

 These were planted in soil in the greenhouse and in the garden and 

 gave 20 and 25 per cent germination respectively. All seeds not 

 planted were again placed in cold storage. Twelve days later 400 

 with hypocotyls protruding from the endosperm were planted in 

 soil in the greenhouse. Of these, 348, or 87 per cent, produced seed- 

 lings within a week. By July 24, 1666 of these 7000 cold storage 

 seeds had germinated at a low temperature. Of the ungerminated 

 seeds 100 placed on moist cotton at room temperature gave 31 

 per cent germination in one week. The roots of these were short 

 and thick and showed a great tendency to coil. At the same time 

 air-dry seeds which had been stored at room temperature, when 

 placed in soil or on moist cotton, decayed. Seeds kept in cold 

 storage showed for the first few days a great tendency to mold, so 

 that it was necessary to sterihze them with a 3 per cent solution of 

 hydrogen peroxide for i hour on two separate occasions. With 

 longer storage an immunity toward fungi is established, and 

 although the coats may be covered with a thick layer of myceha the 

 endosperm and embryo are not attacked. Sections of the seeds 

 examined under the microscope failed to show any hyphae present 

 within the living tissue. On November 6, 191 7, 6 cultures of 50 

 seeds each of both the 191 6 and 191 7 crops were placed in moist 

 storage at 0-2° C, where they were allowed to remain for 140 days. 

 At the end of that time no germination had taken place, which is in 

 direct contrast with the result obtained in 191 6 with seeds stored 

 at 4-6° C. The failure to obtain germination here is interpreted 

 as being due to the use of too low a temperature. The assumption 

 that the exposure to this temperature was too long will hardly 

 explain the results obtained, since if the temperature were not too 

 low germination should begin as soon as the after-ripening process 

 is complete. The results given in table IV, showing the percentage 

 of germination obtained when these seeds were transferred to a 

 temperature of 10-12° C, indicate that the storage temperature 

 and not the length of exposure to it is the limiting factor. 



This conclusion is strengthened further by the following experi- 

 ment. Unfortunately no count of the number of seeds germinated 



