Reprinted for private circulation from 

 The Botanical Gazette, Vol. LXXVI, No. 4, December' 1923 



1 — 



botanjcal 



REACTION OF PROTOPLASM TO SALTS AND 



ANTAGONISTIC ACTION OF SALTS 



AND ALCOHOL 1 



William Seifriz 

 Introduction 



Some recent experiments by the writer on the reaction of the 

 leaf cells of Elodea to certain reagents, revealed a striking difference 

 in the toxic effects of the two bivalent cations, strontium and cal- 

 cium, and a similarity in the effects of the monovalent cation 

 sodium and the bivalent cation calcium. The changes in osmotic 

 pressure and in protoplasmic streaming were qualitatively the same 

 in the case of Na and Ca, but the exact opposite in the case of the 

 two bivalent ions, Ca and Sr. Further, the change in osmotic pressure 

 occasioned by Sr gave every indication of being due to an increase 

 in permeability. These facts all stand in opposition to the widely 

 accepted hypothesis that protoplasm reacts similarly to all mono- 

 valent cations on the one hand, and to all bivalent cations on the 

 other hand, the former increasing, the latter decreasing permeability. 



The experimental work on which this article is based was done in 

 the laboratories of the Botanical Institute of the University of 

 Geneva, Switzerland, where the writer enjoyed the privileges of a 

 guest through the courtesy of the Director of the Institute, Pro- 

 fessor R. Chodat, to whom the writer's thanks are due for many 

 kindnesses. 



Method and material 



The plasmolytic method of determining changes in osmotic 

 pressure of the cell contents was followed. This method is not 

 suitable for accurate quantitative measurements, but does give 

 results which are often in harmony with those obtained by other 

 methods, notably in regard to the order of absorption of different 

 salts. A decided advantage of the plasmolytic method is the fact 

 that the cells studied are under direct observation, so that any 

 abnormal conditions, such as changes in surface tension, viscosity, 



1 Contribution from the Osborn Botanical Laboratory. 

 3S9] [Botanical Gazette, vol. 76 



