196 Charles R. Stockard 



act more violently in the presence ot sugar unless it be due to some 

 action which might take place when the sugar molecules split if 

 they become inverted in the solutions. Eggs are necessarily very 

 delicate chemical indicators and it may be that an action hitherto 

 undetected might be shown by them. Furthermore, Fundulus 

 eggs are exceptionally adapted to the study of such questions as 

 they are not necessarily subjected to abnormally high pressure in 

 experimentation. 



Sea-water mixtures of NH4CI ^ m, i m, and fv m + sugar 

 0.293 "^ were used with rather indifferent results. In each of the 

 three mixtures the yolks were shghtly shrunken and in the two 

 stronger a small per cent of the eggs always died during the first 

 day of development, but from this time until nine or ten days old 

 they developed in a normal manner though somewhat slower than 

 the control. When fifteen days old in NH^Cl \ m + sugar 0.29^ m 

 95 per cent of the eggs were dead and the few embryos alive 

 were small with feeble pulse. They appeared as embryos should 

 when seven or eight days old. In NH^Cl i m + sugar 0.293 "^ 

 50 per cent were dead and the others were small and otherwise 

 like those described above. The eggs in the NH^Cl -f^ + sugar 

 0.293 "^ vvere all normal except for the small size of the yolks. 

 None had hatched. In the 0.293 '^ sugar solution all had a nor- 

 mal development; and in the sea-water solutions of NHiCl \ m 

 and t'3 m development was almost normal except for the contrac- 

 tion of the yolks. The embryos w^ere a little retarded in develop- 

 ment and none of them hatched. These results lead also to the 

 same general conclusion, that the nnxtiire acts more violently 

 than would either constituent acting alone, although the difference 

 in action here is not great. 



SUMMARY AND CONXLUSIONS 



I The membrane of the eggs of Fundulus heteroclitus is 

 readily permeable to salts in solution as is shown in embryos a 

 few days old by the fact that KCl will stop their heart action 

 within a few moments. 



During the early stages the membrane is also easily penetrated 

 since eggs subjected to the action of strong solutions of LiCl for 



