70 Kansas Academy of Science. 



content of the lots of seeds would account for the entire dif- 

 ference. The closeness of the agreement speaks strongly for 

 the accuracy of the methods and for the validity of all assump- 

 tions involved in the mode of procedure. 



The high values found for the internal forces of the seed 

 are significant in connection with the physiology of the seeds 

 of agricultural plants. It has been observed, as, for instance, 

 in Bulletin No. 23, Bureau of Soils, that seeds can secure much 

 moisture from soils which contain only a small amount of 

 water. A loam soil holding 15 per cent of moisture yielded it 

 to air-dry beans so freely that at the end of twelve hours the 

 beans had taken up 60 per cent of their weight of water. A 

 very striking experiment consisted in mixing 50 grams of 

 air-dry cowpeas, whose hygroscopic moisture was about 14 

 per cent, with 50 grams of soil which contained 15 per cent 

 of water. In twelve hours the cowpeas took up 12.1 per cent 

 of their weight of water, leaving only 1.3 per cent in the soil. 

 That is, the soil was nearly air dry. The very high values 

 found for the internal forces of air-dry seeds gives us a satis- 

 factory explanation of this power of seeds to absorb large 

 amounts of moisture from relatively dry soils, and of their 

 ability to secure enough water for germination under such 

 conditions. 



While the seed, by virtue of its powerful internal forces, 

 can secure water for germination, those forces are fully satis- 

 fied and disappear with saturation. As soon as the young 

 seedling begins to establish itself it is left wholly dependent 

 on other much weaker forces for securing its water supply. 

 The seed is admirably adapted to bring about conditions under 

 which these new forces become effective in the life of the 

 plant. 



