1 66 SAKYO KANDA. 



alone, therefore, cannot antagonize the toxic action of sodium and 

 potassium salts. 



11. In the magnesium-free artificial sea-water, many remain 

 positive to light. This fact may be explained as an antagonistic 

 action of calcium toward sodium and potassium salts which 

 acting by themselves are negativating agents. 



12. Alcohols (methyl, ethyl, n-propyl, n-butyl) as used by 

 the writer are not favorable as negativating agents at room tem- 

 perature, though they are good at higher temperature. The 

 higher the alcohol in the series the greater negativating effect 

 it has. 



13. Most of the larvae treated with esters, methyl and ethyl 

 acetate, became negative at higher than room temperature. 



14. Other compounds, chloroform, formalin, ether and saponin, 

 produced little or no reversal while the larvae were in the solu- 

 tions, except saponin at higher temperatures. 



15. Monobasic fatty acids are the best of all chemicals used 

 for this work. The higher the acid in the series the greater 

 negativating effect it has. 



1 6. Some narcotics "antagonize" or retard the reversing 

 action of butyric acid. 



17. The reversing effect of a very weak concentration of 

 butyric acid (.00006 m.) in artificial sea-water is great. 



18. Hydrochloric and sulphuric acids produce negative helio- 

 tropism, almost as well as fatty acids do. 



19. In producing negative heliotropism, NH 4 OH is much more 

 efficient than strong bases. 



20. Arenicola larvae treated with narcotics become negative 

 after returning into normal sea-water. 



