116 



SAKYO KANDA. 



prepared were transferred by means of a pipette into the Dewar 

 tube with special care to make the least current. The tube was 

 closed with a rubber stopper. The results based on many ex- 

 periments are given in Table I. 



TABLE I. 



EFFECTS OF TEMPERATURE (?). 



Cooling water to 3, 4, or 5 C. and warming to 35 C. were 

 also tried. At a temperature 5 C., the animals were somewhat 

 active, and showed a tendency to swim downward. Another 

 series of experiments was also carried out in an incubator and in 

 an ice box. Each experiment lasted three days. The tempera- 

 ture in the incubator ranged from 30 C. to 34 C. In one series 

 of the experiments, the animals so treated in the incubator were 

 "positively geotropic"? That is to say, a majority of the ani- 

 mals always staid at the bottom of the tube, as Sosnowski ob- 

 served. But in others, the results were very irregular and var- 

 iable. Experiments in the ice box were not satisfactory, because 

 it was very hard to keep the temperature constantly low. 



The writer found that the animals always swam downward, 

 whenever transferred, no matter how carefully it was done. This 

 occurred invariably even in water of the same temperature as 

 the culture, when the animals were transferred into it. It seems 

 to the writer, therefore, to be possible that this reaction was mis- 

 taken as reversibility of geotropism of the animals by tempera- 

 ture. That the animals swim downward, i. e., their negative 

 geotropism is reversed, whenever transferred, would suggest 



