- 129 



It would seem possible^ that the highly nitrogenous character 

 of leguminous plants may have been acquired as a result of long 

 continued nutrition with nitrogen, supplied from the root-nodules 

 in a form which lends itself to more rapid production of proteids 

 than is possible when practically the whole of the nitrogen is taken 

 up as nitrates as is the case with non-leguminous crops. 



W. J. V. OSTERHOUT. On similarity in the behaviour of so- 

 dium and potassium in plants. (Bot. Gaz., 48, 1909, No. 2, 

 p. 98-104. E. S. ft., XXI, December 1909). 



The author carried on two extensive series of experiments with 

 the chlorides of sodium and potassium to determine the commonly 

 accepted statement that potassium and sodium, while agreeing clo- 

 sely in chemical behaviour, have fundamentally different effects upon 

 plants. Most of the experiments were carried on with wheat, but 

 other plants as algae, liverworts, equisetum, and various genera of 

 flowering plants were also used. 



The results obtained show that the accepted idea that sodium 

 and potassium have entirely different effects upon plants is not 

 valid in the field of toxic and protective action, but that their be- 

 haviour shows the close similarity which would be expected when 

 their near chemical relationship is considered. 



W. E. BRENCHLEY (of the Rothamsted Exp. Station). The influence 

 of Copper Sulphate and Manganese Sulphate upon the 

 Growth of Barley. (Annals of Botany, vol. XXIV, No. XCV, 



p. 571. London, July 1910). 



The following is the summary of Miss Brenchley's paper: 

 " i. The action of plant poisons in dilute solutions is masked 

 by the presence of nutrient salts, which thus enable .plants when 

 grown in such solutions as water-cultures to endure a much greater 

 concentration of the toxic substance than in the absence of nu- 

 trients. 



2. Copper sulphate, which is a definite poison to barley, does 

 not have any stimulative effect in very dilute solutions, even at so 

 low a concentration as i : 10000000. 



3. Manganese sulphate, though not an actual toxic to barley, 

 retards the growth very considerably if supplied in moderate quan- 

 tities. Minute traces of the salt have a decided stimulative action 

 both on the root and shoot. 



