F. KiDD AND C. West 235 



of water, and they believed that the main effect of using as small an 

 amount of water as possible lay in reducing the loss by exosmosis of 

 essential soluble food-reserves during the process of soaking. It may be 

 pointed out that the minimum amount of water is at the same time a 

 favourable condition for the supply of oxygen to the seed and for the 

 removal of carbon dioxide from the seed during soaking. The time of 

 immersion employed varied from 24-100 hours according to the species 

 of seed under investigation. Generally speaking the time of immersion 

 allowed was just long enough for the swelling of the seed to become 

 complete. These authors, in view of the possible economic application 

 of this seed-treatment, carefully tested how far the re-drying of the seed 

 would affect the results, and found that in general the re-drying of the 

 seed after soaking, especially if carried out slowly, did not appreciably 

 alter the beneficial influence of the process. The following general 

 conclusions may be drawn from their experiments. 



(I) Effect on germination. 



(a) Seeds soaked in the minimum amount of water and afterwards 

 sloivly dried at ordinary temperatures imbibe water and develop more 

 quickly, when again allowed to take up water and germinate^, than 

 untreated seeds. 



{h) Seeds which are rapidly dried after the initial soaking germinate 

 more slowly than untreated seeds. 



(c) Seeds swollen in water and sown in the still moist condition 

 germinate more quickly than untreated seeds. 



(II) Effect on subsequent growth and final yield^. 



(a) In general, seeds soaked in water previous to germination give 

 rise to slightly fewer plants than untreated seeds. If the seeds are re- 

 dried too rapidly the number of plants produced may be considerably 

 diminished. 



(6) Soaking seeds in water previous to germination tends to accen- 

 tuate individual differences in the growth of the plants produced from 

 them. 



(c) Plants from seeds swollen in water previous to sowing develop 

 at first more quickly than those from untreated seeds, but this initial 

 difference in growth tends to disappear later on. 



1 For detailed experiments dealing with this point see Tautphoeus (35). 

 - It is immaterial whether the seeds after swelling in water are slowly re-dried before 

 sowing or whether they are sown at once in the moist condition. 



