[Vol. 2 



490 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



for fig. 2 being run in the fall when the seeds were fresh, and 

 that for fig. 3 in the winter), in the vigor of the seeds, and in 

 the difference in the units used in plotting the curves. It must 

 be said, however, that various factors of the problem of 

 exosmosis from the roots of plants remain as yet unknown. 



The early drop in the curve of the conductivity of the con- 

 trols (1-4) is an interesting feature which would seem to be 

 explained by an adsorption of the electrolytes on the surface 

 of the chemically clean glass tumblers. 



At the end of 20 days in distilled water the roots of the 

 plants which had not been in full nutrient at all showed marked 

 deterioration (being badly decomposed and covered with a 

 gelatinous coating), while the roots of those which had previ- 

 ously been in full nutrient solution for some time remained 

 normal in every respect, even after 20 days in distilled water. 



These results seem plainly to indicate that injury which 

 plants sustain in distilled water is very closely related either 

 to the lack of available nutrients in the medium or of reserve 

 food material in the tissues. A seedling is in an exceedingly 

 plastic state of growth. If no food materials become avail- 

 able the embryonic tissues which are in such an active condi- 

 tion of growth soon become disorganized, possibly suffering 

 partial autolysis and becoming the prey to bacterial and 

 fungous action. We would expect, therefore, that the larger 

 the seeds (and hence also the supply of stored materials), the 

 longer the seedlings could remain in distilled water before 

 deterioration. Comparison of True's results on Lupinus with 

 those here presented on Pisum sativum and Vicia faba seems 

 to fulfill that expectation. We should also expect that the 

 more nutrient materials the plant absorbed, the better it 

 would be able later to withstand any deteriorating influences 

 in the distilled water, and the experiment above noted seems 

 to bear out that idea also. 



In the light of what has been said we are led to believe that 

 the conductivity curve of Nos. 5-8 is not a pure representa- 

 tion of exosmosis and that the products of bacterial and 

 fungous action and cell decomposition account for at least a 

 part of the conductivity. While the same condition may be 



