1906] OSTERH OUT BALANCED SOLUTIONS 133 



ologically balanced solution; this will be more fully discussed in 

 the second portion of the paper.) 



3. The poisonous effect of NaCl is inhibited little or not at all 

 by KC1 or MgCl 2 added singly. 



4. The combination NaCl-f KCl + CaCl 2 is superior to NaCl + 

 MgCl 2 + CaCl 2 , but the latter is better than NaCl + MgC^^Cd. 



5. These effects must be due to the metal ions, since the anion 

 is in nearly all cases the same. 



The plants of Group 2 agree with those of Group i except in their 

 behavior toward distilled water. 



Essentially similar results were obtained from the study of fresh 

 water algae and other plants, the details of which will be given in 

 the second part of this paper. 



These results agree in striking fashion with those obtained from 

 the study of marine 7 and freshwater animals 8 . 



The combination NaCl + KCl + CaCl 2 (in the same proportions 

 as in sea water) seems to be quite generally beneficial for animals 

 and plants. 



We may in conclusion briefly consider the effects of concentrated 

 solutions. A series of experiments were made on Enter omorpha 

 Hopkirkii in which the plants were placed in dishes with a very little 

 sea water. This quickly evaporated, so that the plants became 

 covered with salt crystals in 24 to 48 hours. In this condition some 

 of them remained alive for about 150 days. This means that Entero- 

 morpha plants which remain alive only 15 days in 3^/8 NaCl solu- 

 tion can live 150 days in an NaCl solution of 10 to 12 times .higher 

 concentration, provided the other salts of the sea water are present 

 in the solution (at corresponding concentration) to inhibit the toxic 

 effect of NaCl. Experiments on Lyngbya, Ptilota, and Pterosiphonia 

 gave essentially the same results. 



In view of these results, and others of a similar character shortly 

 to be published, it appears certain that physiologically balanced salt 

 solutions have the same fundamental importance for plants as for 

 animals. 



7 LOEB, Pfliiger's Archiv 107:252. 1905, and the literature there cited. 



8 OSTWALD, Pfluger's Archiv 106:568. 1905. Univ. of California Publications, 

 Physiology 2:163. I 95- 



