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from water, and agreed among themselves in that they all 

 contained the six kinds of Inorganic atoms or atomic groups 

 (potential ions) known to he needed for plants in general, 



l3ut as has heen made clear -- they did not contain these 



atoms and groups in the same proportions. It is clear that 

 the presence of a slifht osmotic value due to the salts used, 

 or the presence of a small amount of the essential atoms and 

 atomic groups in the solutions, greatly improved the water for 

 the growth phases here dealt with. Since the solutions differed 

 markedly in salt and salt proportion and at the same time were 

 all essentially alike In their influence; on the plantlets, it 

 seems probable that any lower total concentration of any of 

 these solutions (between 0.1 atm, of potential osmotic press\ire 

 --the solution concentration used-- as In the case of water) 

 would have shown growth rates more like those secured with 

 water than like those obtained from solution actxially tested, 

 but still alike among themselves for the solution series. 1$ 

 is practically certain that if the solution concentration had 

 been great e r f'wlth an osmotic value greater than 0.1 atm. of i 

 potential pressxire)^ they would have shown some relations • 

 between shoot growth and salt composition, even with seed as 

 variable as that here used, ""ith what total concentration 

 value this might occur is of course not predictable without 

 experimentation. 



TO the conclusions thus far reached may now be 

 added these, that all these solutions used are much better 



