1906] OSTERHOUT—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 KCl or MgCl, added singly. 
4. The combination NaCl+KCl+CaCl, is superior to NaCl+ 
MgCl,+CaCl,, but the latter is better than NaCl+ MgCl, +KCl. 
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 1 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? and freshwater animals®. 
The combination NaCl+KC1+CaCl, (in the same proportions 
as in sea water) seems to be quite generally beneficial for — 
and plants. 
We may in conclusion briefly consider the effects of concentrated 
solutions. A series of experiments were made on LEnteromorpha 
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 1 50 days. This means that Entero- 
morpha plants which remain alive only 15 days in 3m/8 NaCl solu- 
tion can live rs0 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 
Save 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 Los, Pfliiger’s Archiv 107:252. 1905, and the literature there cited. 
8 Ostwatp, a Archiv 106:568. 1905. Univ. of California Publications, 
P pias 2:163. 1905. 
