198 Charles R. Stockard 



high in sea-water produced a much less marked effect. Such 

 o'-servations seem to indicate that the eggs were less resistant to 

 chemicals when treated in fresh water, due possibly to a slightly 

 weakened condition when out of their usual medium. The fresh 

 water solutions showed a strong tendency to become acid and a 

 fungus-like growth was often present (see footnote, p. 178). It 

 will also be recalled that the acid condition of the medium would 

 in itself be injurious to the eggs. 



4 Eggs that were subjected to the action of LiCl, LiNOg and 

 Li2S04 were all affected in a similar manner, seeming to indicate 

 that the cation common to the three salts was the active principle 

 concerned. Of the large number of other salt solutions employed 

 none of the metallic ions gave the same constant abnormalities 

 which lithium induced. The lithium larva of Fundulus is as 

 definite and well marked as those recorded by Gurwitsch and Mor- 

 gan for the frog. 



5 <2 It was found, as Loeb had already shown, that this egg 

 will develop in solutions of KCl and live for several weeks without 

 developing a heart beat. Loeb's statement that the circulatory 

 system develops normally is incorrect, since the heart itself is abnor- 

 mal, the pericardium is often greatly swollen, and other portions 

 of the system are defective. Although eggs will live and develop in 

 these solutions if placed in them soon after fertilization an embryo 

 several days old will be killed in a few moments if treated in a like 

 manner. Thus when the heart's action has once become estab- 

 lished the embryo can no longer withstand the action of KCl. 



b The effects of NH^Cl on these eggs were rather general, 

 development was retarded, the blastopore was slow closing and 

 many short embryos resulted. The circulation was poor. Some 

 lived in these solutions for eighteen days though none hatched. 



In mixtures of NH4CI with MnCls eggs were less affected than 

 in solutions of either of these salts used singly. This fact may be 

 due to the antitoxic action of one cation on another as Loeb has 

 claimed to take place. 



c MnClj solutions prepared in fresh water caused a thickening 

 or concentration of the central periblast in early stages, develop- 

 ment was retarded, and the embryo had a feeble pulse. Some of 



