JACQUES LOEB 



239 



The same fact can be demonstrated equally well with other toxic 

 solutions; e.g., Nas citrate. If newly fertilized eggs of Fundulus are 

 put into m/100 Nas citrate practically no egg can form an embryo, and 

 the result remains the same if the m/100 solution of Naa citrate is 

 made up in different concentrations of LiCl or NaCl. When, how- 

 ever, the m/100 solution of Nas citrate is made up in KCl, RbCl, 

 CsCl, or NH4CI a considerable number of eggs develop into embryos 

 as indicated in Table II. 



TABLE I. 



TABLE II. 



The table shows that when the m/100 Nas citrate solution is made 

 up in m/5 KCl, RbCl, CsCl, or NH4CI practically half the eggs form 

 embryos. In this experiment the addition of the CI ion may diminish 

 the toxicity of the citrate solution but if this be true the fact remains 

 that the CI ion can have this effect only when it is added with K or 

 NH4 ions and not when added with Na or Li ions. 



