— 26 — 



(2) It may further be asserted that in this country the greatest 

 influence is exerted by moisture on seeds between June and September. 



3. Persistence of the Germinating Power in Relation to 

 THE Atmosphere (refer Experiment I). 



How does the air contained in the receptacle of the seeds influ- 

 ence up the germinating power of the latter? Seeds so long as they are 

 alive must, of course, continue to perform respiration, and seeds placed in 

 a perfect vacuum must perish. The air pumps in common use, however, 

 do not produce an absolute vacuum, but only rarefy the air. Excepting 

 camphor-seeds, the presence of ordinary air is always desireable for the 

 preservation of seeds, and there is no need of keeping them in rarefied air. 



4. Persistence of Germinating Power in Relation to 

 Intensity of Light. 



What influence light has upon the germinating power of tree seeds, 

 is not yet determined by the two experiments made. Still, excepting 

 Akamatsu, all seeds placed in the light showed better results than those 

 placed in the dark. The same result was arrived at by Moroku Nohara 

 who tried experiments on the preservation of seeds of hybrid of Salix 

 purpurea L. var. mulinervis Matsum. and Salix gracilistyla Miq. (cf. Tokyo 

 Botanical Magazine, XXVII, 1913). The same report shows that seeds 

 should never be placed in the dark as had hitherto been believed best as 

 this is quite unfavorable for the preservation of germinating power. 

 Whether the effect is due solely to light and how light influences the 

 physiological functions of the seeds are questions that remain unsolved 

 and further study of the subject is desirable. 



III. Conclusions 



From the statements above given we conclude as follows: — 

 The persistence of the germinating power of forest tree seeds varies 

 according to species, and is influenced by the suroundings where seeds 

 are kept. Of the seeds tried, Kuromatsu and Akamatsu keep their 

 germinating power best being followed by Karamatsu, Sugi and Kusu in 

 order while Hinoki loses its germinating power the soonest. 



