1908] SCHREINRR 6- REED— TOXIC PLANT CONSTITUENTS 79 



substances in a more highly oxidized stage are actually beneficial to r 

 plant growth- 

 It is of great interest to note in this connection that green manures 

 may have the same action. When first applied to the soil they may 

 exert a depressing effect upon the growth of the crop. After enough 

 time has elapsed for the decomposition of the vegetable matter, with 

 change to other compounds, the crop shows a marked benefit from 

 the action of the green manure. 



REX 



The lecithins are readily decomposed and split off cholin and 

 complex glycerophosphoric acids, which upon further decomposition 

 yield fatty acids, glycerin, and phosphoric acid. It is such a dccom- 



^ ^ ^ ^ 



'ermmatms: 



the absence of light. 



decomposition 



ithins is due to enzyme action. He has shown 



phosphorus compounds are quickly and almost completely decom- 

 posed during germination, only 2 per cent, remaining unattacked. 

 ScHULZE ('91) and other investigators have reported the occurrence 

 of cholin in various plant tissues associated -with lecithin, and it does 

 not follow that it must always be regarded as a product of the decom- 

 position of lecithin. 



eurm 



may also be formed 



ros, as Schmidt 



It 



with baryta water. Betain or ox}-neurin may be prepared artificially 

 by the oxidation of cholin, LoEW ('99; reports that betain is a favor- 

 able and cholin is a moderately good source of carbon for bacteria. 



In our experiments with wheat seedlings, neurin was found to be 

 very toxic, cholin moderately toxic, while betain was entirely harm- 

 less. WTieat plants were killed by solutions containing 250 ppm. of 

 neurin and mjured by solutions containing 25 ppm. It was thought 



urv 



erties of neurin. The experiment was accordin^y repeated, usmg 

 neurin which had been neutralized with acetic acid. The result, how- 

 ever, was not different from the experiment m ^ich the neurin was 

 not neutralized. It may be possible that a part of the difference in 



