Tox1o AND ANTITOXIC Errects or Ions’ 721 
The addition of } to 2 ¢.c. of m KCl or K,SO, occasionally 
yielded results, in that 1-5 per cent. of the eggs formed 
embryos. Lithium salts showed themselves to be even less 
active. I occasionally obtained a slight antitoxic action by 
the addition of large amounts of NH, salts. Whether 
hydrogen ions can yield better results must be determined 
through further experiments. 
7. Not only can the poisonous effects of a pure sodium- 
chloride solution be annihilated through the addition of 
small amounts of bivalent or trivalent kations, but it seems 
as though the same holds for all salts which, like NaCl, havea 
univalent kation and anion. No embryos develop ina 3m LiCl 
solution. By the addition of small amounts of Ca(NO,),, 
BaCl,, SrCl,, or MgCl,, 50-60 per cent. of the eggs were 
caused to form embryos, which developed normally. Other 
kations of a higher valency were not tested. I obtained 
entirely similar results in regard to KCl. In a {m or even 
a im KCl solution an egg may occasionally develop. When 
a small quantity of MgCl,, Ca(NO,;),, SrCl,, BaCl, or 
FeSO, was added, the poisonous effects of the pure KCl 
solution were annihilated. Of salts having other bivalent 
kations, only ZnSO, (a single experiment) was used. An 
effect was obtained in this case also, but it was less striking 
than in the case of the other bivalent kations. 
NH,Cl seems to be the least toxic of all the salts men- 
tioned thus far. Even in a ?m NH,Cl solution an embryo 
could form occasionally. This immunity of the Fundulus 
egg against NH,Cl is perhaps related to its great immunity 
against urea. I cannot get rid of the suspicion that a per- 
centage of the NH, ions is perhaps done away with in the 
metabolism of the egg. I obtained striking antitoxic effects 
with small amounts of SrCl, and, although less definite, 
of FeSO,. Ca(NO,), increased the number of embryos 
formed, though not as greatly as the other salts with a 
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