122 Asa Arthur Schaejfer 



Fifteen days after the experiment was begun, Raphidium 

 developed in the glasses and the Stentors died. About six of the 

 dishes which contained paramecia and ink or carmine were howT 

 ever in good condition. These paramecia showed no decrease m 

 the number of vacuoles ot these substances. After two or three 

 days these paramecia also died. 



These results are quite at variance with those described by 

 Metalnikow. I therefore contrived ajiother experiment which 

 eliminates certain possibilities of error to which the above experi- 

 ment and those of Metalnikow were open. A clinostat was set 

 up with a cylindrical jar revolving on the horizontal axis once in 

 every 15 minutes. Seven small vials were then filled with Stentors 

 and paramecia in 5 cc. of their own culture solution. In 3 of 

 these vials was placed carmine; in the other 3 india ink; and the 

 other was left for a control. The vials were corked and placed 

 loosely in the jar revolved by the clinostat. As the clinostat 

 revolved the jar, the vials rolled around, and as they did so their 

 contents were shaken up thoroughly about three times every 15 

 minutes. In this way the contents of the vials were distributed 

 uniformly for the thirty-three days throughout which the experi- 

 ment was carried on. The Stentors, paramecia, and culture solu- 

 tion were placed in the vials in the same proportion in which they 

 existed in nature. A little fresh carmine or ink was added every 

 few days. The contents of the vials were examined every day, 

 whenever possible, in this manner. The contents were poured out 

 into a small preparation dish and placed under a binocular micro- 

 scope. The condition of the Stentors and paramecia was then 

 easily observable. In this way the water in the vials was also 

 thoroughly aerated. About 30 Stentors and 500 paramecia were 

 placed in each vial. The following are the tabulated results for the 

 paramecia. The table shows the number of paramecia which con- 

 tained no ink or carmine on the dates shown. 



