324 PROCEEDINGS OF THE INDIANA ACADEMY OF SCIENCE. 



ing protoplasm. When the movable contents was compactly thrown to one 

 end of the cell, it could be ascertained that it equalled about one-seventh of 

 the volume of the cell. When the contents were thrown to one side of the cell 

 its redistribution was somewhat more ranid owing to the fact that there was 

 a much greater surface over which redistribution could take place. The aver- 

 age time for redistribution of the contents of a larger number of specimens 

 at 22° C. when their contents was eentrifuged to one side was two days. 



After the contents had returned, ] eentrifuged the same specimens of 

 Closterium moniliferum again using 1207 g. as before. The contents were dis- 

 placed as expected. One of the tubes of specimens I placed in the light and 

 the other was put in the dark. T'le contents returned in all the specimens as 

 before. In the case of those specimens in the light, however, the contents 

 returned completely in three days at 22° C. The specimens which were 

 placed in the dark required a considerably longer time, as complete redis- 

 tribution of their contents only occurred in five days. As the contents re- 

 turned to their normal position in the cell in the light after a second centrifug- 

 ing in the same length of time as before, the activity of the cells did not seem to 

 have been diminished. The cells did not seem to have be(>n injured by such 

 treatment. The influence of the light promoted a more rapid return of the 

 contents and darkness had ? somewhat retarding effect, as might be supposed. 



The movements of Closterium moniliferum were not stopped bv low centri- 

 fugal force as shown both before and after centrifuging. 



