— 23 — 



The two experiments show that persistency of germinating power 

 differs considerably with the mode of preservation adopted and the sur- 

 rounding conditions. 



1. Persistence op Germinating Power with Regard to 



Temperature. 



That low temperature is indispensable for the preservation of tree 

 seeds was clearly shown by the results of the two experiments. Parti- 

 cularly, in the second experiment, Akamatsu-seeds kept air-tight in a 

 cellar, where the temperature was rather low, in front of the same seeds 

 which were kept air-tight in a room, where the temperature was relatively 

 higher and the fluctuation likewise considerable, showed not the marked 

 distinction in the fall of germination percentage untill March or even 

 June of the third year after the crop. The fall of the power for the first 

 year or year and a half after gathering is regardless of temperature but 

 for longer periods the germinating power depends upon the mode of 

 preservation. The great resistance of Akamatsu-seeds to changes of 

 temperature is thus explained. 



Sugi-and Hinoki-seeds, on the other hand, show a great difference 

 even in early days. Those kept in a colder temperature showed a great 

 advantage over those kept, in a warmer temperature. One must also note 

 that the resistance of Hinoki-seeds to changes of temperature is small as 

 compared with other seeds. Indeed, Sugi-seeds which in an ordinary 

 room can only keep their germinating power for one year when kept in 

 a cellar in an air-tight condition preserve a high germination percentage 

 even as late as the sowing season of the 3rd year. 



Hinoki-seeds lose their germinating power by March of the third year 

 after gathering, no matter what means of preservation are adopted. This 

 shows that Hinoki-seeds are more affected by the surrounding temperature 

 than Sugi-seeds so that perfect preservation can only be attained by 

 providing still a temperature lower than that in cellar of a minimum of 11°C. 



In proof of this, we have the following fact: — 



The staff of Kochi Major Forest Reserve kept Hinoki-seeds in a subter- 

 ranean cavity at Shiragayama, Kochi, where the people store silk worm 

 eggs and where the temperature ranges between 0° to 8°C. The seeds so 

 stored gave a high germinating percentage. 



