3RARV Re P rmted from THE BOTANICAL GAZETTE, 42: 127-134, August, 1906 



W/f/Uj 3A 



*&* *>"* (I IAGRICI 



ON THE IMPORTANCE OF PHYSIOLOGICALLY 



BALANCED SOLUTIONS FOR PLANTS. 1 ^. 



I. MARINE PLANTS. 



W. J. V. OSTERHOUT. CALr 



RINGER demonstrated that animal tissues live longer in a solut 

 of NaCl to which a small amount of KC1 and CaCl 2 is added than 

 in a solution of NaCl alone. Various explanations of this fact were 

 given by different investigators, all of whom, however, agreed upon 

 the essential point that KC1 and CaCl 2 are essential for the mainte- 

 nance of life. 



HOWELL assumed that CaCl 2 is the stimulus for the heart beat, 

 while NaCl is an indifferent substance, necessary only for the mainte- 

 nance of osmotic pressure. Similarly RINGER concluded that Ca is 

 the stimulus for the systole, while K is necessary for the diastole of 

 the heart beat. 



HERBST made experiments on the influence of the composition of 

 the sea water on sea urchin eggs, eliminating in each successive 

 experiment a different constituent of the sea water. He found that 

 the eggs would not develop in any solution which did not contain 

 all the salts of the sea water. From this he concluded that each of 

 the salts found in sea water is necessary for the development of the 

 egg. LOEB called this view in question as the result of his experiments 

 on Fundulus. He found that this marine fish cannot live in a pure 

 NaCl solution of the same osmotic pressure as the sea water, but that 

 it can live indefinitely in a mixture of NaCl, KC1, and CaCl 2 , in the 

 same proportions in which these salts are contained in sea water. 

 The fish can also live indefinitely in distilled water. This proves 

 that it does not need any of the three salts mentioned for the mainte- 

 nance of its life, and that the Ca and K are only required to overcome 

 the poisonous effects which would be produced by the NaCl if it 

 alone were present in the solution (at the above mentioned concen- 

 tration). 



1 I wish here to express my sincere thanks to Professor LOEB, who kindly placed 

 the facilities of his laboratory at my disposal and assisted me in every way during 

 these investigations. 

 127] [Botanical Gazette, vol. 42 



