48 S. O. MAST AND F. M. ROOT 



5. If the ends of the pseudopods fuse so as to take on the form 

 of a ring around the Paramecium and if the cutting is due to con- 

 striction in this ring, and if the constriction in this ring is due to a 

 change in surface tension, the work involved requires a minimum 

 reduction along the inner surface of the ring of "at least 383 dynes 

 per centimeter. 



6. The bulk of evidence at hand seems to indicate that the 

 paramecia are divided by the approach of two pseudopods. To 

 account for the process on the basis of the surface tension theory 

 therefore, the surface tension of the amebae would have to be, 

 at the very least, much higher than 383 dynes per centimeter 

 and in all probability considerably higher than 1118 dynes per 

 centimeter. The surface tension of protoplasm is, however, only 

 approximately 50 dynes per centimeter. It is, therefore, prob- 

 ably at best an insignificant factor in the process of feeding in 

 ameba. 



