u8 



SAKYO KANDA. 



not stay there very long. They resumed their negative geotro- 

 pism within one hour. Sosnowski already observed the same and 

 stated that "wenn sich darauf die Tiere wieder an der Oberflache 

 sammeln, kann man durch Zusatz einer neunen Quantitat Saure 

 resp Alkali wieder die Ansammlung am Boden versanlassen." 

 This statement is true. But it should be remembered that the 

 same is also true when some tap water is added. It seems to the 



TABLE II. 



EFFECTS OF CHEMICALS. 



writer that this means that the so-called reversible effect of 

 chemicals on the negative geotropism of Paramecium is not 

 specific but general. Moreover, the animals, whenever trans- 

 ferred to another receptacle without changing the solution, swim 

 downward, and reversed animals do not stay long at the bottom. 



There is, therefore, reason to believe that this is the same phe- 

 nomenon that we met in the temperature experiments. The 

 writer concludes, therefore, that mechanical "shock" or agitation 

 of transferring, or chemical "shock," is chiefly responsible for 

 so-called reversible effect of chemicals on the negative geotropism 

 of Paramecium but not chemicals themselves. 



Besides the chemicals mentioned above, sodium chloride, 



1 This was adopted as approximately Sosnowski's strength. 



