EXPERIMENTS ON STORAGE OF SEEDS. 1 39 



excessive moisture, but equally exposed to low temperatures. 

 The same holds more or less for the fruit of the ash and Robifiia. 



What vital processes are active in the resting seed? Seed and 

 fruit must be regarded as living organisms; they respire and 

 transpire. Respiration is a process of destructive metabolism ; 

 the changes involved in the breaking down of the organic sub- 

 stances result finally in the liberation of carbon dioxide and water. 



Respiration is principally affected by temperature. It 

 increases with the temperature until an optimum is reached 

 and then decreases. Transpiration is also influenced by 

 temperature, and also to a considerable extent, as may easily 

 be understood, by the humidity of the air. It is known 

 that a low temperature reduces the activity of respiration 

 and transpiration, and thereby reduces the process of destructive 

 metabolism. This fact is of great importance in adjusting 

 suitable conditions for seed storage. 



In nature's store-house, low temperatures prevail (winter 

 temperature). These temperatures are not constant but vary 

 above and below freezing-point. There is also a relatively 

 high percentage of soil and air moisture. Nature sows lavishly, 

 hence in spite of losses caused by animals and unsuitable 

 germinating beds, there is always enough seed to provide for 

 regeneration. The extravagance in which nature seems to 

 indulge is not permissible in artificial sowing. 



If the seed is to be stored over winter until a suitable time 

 for germination arrives, then the first consideration is the 

 provision of suitable storage conditions, and in selecting these 

 conditions we must take nature as the guide. Only by this 

 means, together with our knowledge of the physiological 

 activities of the seed, can we arrive at the most advantageous 

 method of storing seed in small or large quantities. It was 

 quite apparent that it was necessary to investigate the 

 influence on the seed of the two factors, temperature and 

 moisture. With this object in view I arranged the first set 

 of experiments to simulate natural conditions as nearly as 

 possible. I also made provision for control experiments. The 

 outstanding conclusion appears to be in favour of a cool 

 store (room) or ice cellar (as also mentioned by Haack in 

 his above cited work) for seed storage on a large scale. ^ 



^ In the U.S.A. cold slorage is provided for fruit. In these stores the 

 temperature is kept at aVjout 33° to 35 '5°. 



