1902.] SOTE ON THE BEHAVIOUR OF PLANTS. 209 



The effects of these nitiMtes n[)Oii rice and tobacco showed much 

 analogy to those just mentioned; especially the leaves of tobacco developed 

 very well with calcium nitrate. 



We notice from these tables that magnesium nitrate exerted a very 

 injurious influence and that further sodium nitrate and potassium nitrate 

 retarded the growth compared with the control case, while calcium nitrate 

 exerted in the case of wheats, onions and tobacco such a beneficial influence 

 that the plants were thriving better than in the control case. It is cer- 

 tainly of interest that calcium nitrate had in absence of other nutrients 

 much better effect on plants than potassium nitrate under the same 

 conditions. 



Since all the plants used were very young they had very probably 

 some mineral food from the seeds still available within their tissues. It is 

 further worth mentioning that the onion plants kept in magnesium nitrate 

 had gradually assumed a graysh or blue green colour, very much in contrast 

 with the normal green appearance of plants in potassium nitrate, calcium 

 nitrate and in the control case. 



In addition I compared also the action of barium nitrate with that 

 of calcium nitrate and observed in confirmation of the result of U. Suzuki, 

 Nogakuhakushi, a poisonous action of barium nitrate. Thus the shoots of 

 soya beans kept in one percent solution of barium nitrate had died after 

 ■i days, the shoots of wheat after 13 days, and those of onions after 1.5 

 days. 



