92 University of California Publications in Agricultural Sciences [Vol. 3 



bryos in the eggs. He also found a similar result with sea-urchins, 

 Hydromedusa gonionemus, and a jellyfish, Polyorchis. 



Lillie found that with the larvae of Arenicola the ciliary move- 

 ment goes on in a solution containing 20 parts of NaCl (5/8n) and 

 8 parts of KC1 (5/8n), while each salt used alone stops the movement 

 altogether. 



Ostwald 13 with fresh-water Gamma rus has shown that there is a 

 distinct antagonism between K and Na ions in regard to the duration 

 of life of that animal. Matthews 11 has found that it takes twice as 

 much KC1 to neutralize the toxicity of NaCl in the case of the devel- 

 opment of embryos in the eggs of Fundulus. This is rather similar 

 to the case of yeast, where it takes .2M KC1 to neutralize the toxicity 

 of .14M NaCl to allow the highest growth. 



(c) Bacteria. — Lipman 23 with Bacillus subtilis has found that none 

 of the combinations of these two salts gives as favorable conditions 

 for growth as is found with each salt alone at the same concentration, 

 thus showing non-antagonism between the two salts. 



To summarize the results in this experiment, it may be said that 

 with yeast, like valences prevent the antagonistic effects, contrary to 

 what was found by Lipman with soil bacteria, but in accordance with 

 the results of Osterhout with wheat, Loeb with Fundulus, and other 

 investigators with other organisms. The yeast agrees in this case with 

 all the above-mentioned cases except with that of green algae tested 

 bv Osterhout and that cf Bacillus subtilis by Lipman. 



SERIES X— ANTAGONISM BETWEEN POTASSIUM CHLORIDE AND 



MAGNESIUM CHLORIDE 



The experiments in this series were conducted like the others. The 

 highest growth in this case was found at H, the point where .6M KC1 

 and .5M MgCL were combined in a ratio of about 1 :1. In the case of 

 simple salts KC1 alone at .2M concentration allowed the highest growth 

 up to about 30y 2 millions and MgCL at .1M about 26y 2 millions. KC1 

 alone at .6M and MgCL at .5M permitted the growth of yeast more 

 than is found in this combination at H. But this indicates a mild 

 antagonism, because the toxic effect was less than the sum of the 

 separate toxic effects of the two salts used alone. Distinct antag- 

 onism to the effects of MgCL is shown by KC1, but not the converse. 

 For example, .8M MgCL alone allows the yeast to grow only to 

 8 millions, while in the combination with .1M KC1 the growth has 



