ON THE IMPORTANCE OF PHYSIOLOGICALLY 
BALANCED SOLUTIONS FOR PLANTS.’ 
I. MARINE PLANTS. 
W.cJ. V.OSteR nour. 
RINGER demonstrated that animal tissues live longer in a solution 
of NaCl to which a small amount of KCl and CaCl, 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 KCl and CaCl, are essential for the mainte- 
nance of life. 
HowELt assumed that CaCl, is the stimulus for the heart beat, 
while NaC] is an indifferent substance, necessary only for the mainte- 
nance of osmotic pressure. Similarly RrNGER concluded that Ca is 
the stimulus for the systole, while K is necessary for the diastole of 
the heart beat. 
HERgstT 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. Loe 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, KCl, and CaCl,, 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). 
I wish here to express my sincere thanks to Professor Logs, who kindly placed 
the facilities of his laboratory at my disposal and assisted me in every way during 
these investigations. ‘ 
ae {Botanical Gazette, vol. 42 
