ADVENTITIOUS REPRODUCTION IN HARENACTIS. 13 



The results of these experiments can be more readily inter- 

 preted in accordance with the hypothesis that polarity and sym- 

 metry are essentially molar localizations or gradation of processes 

 along an axis or axes, than with that which regards polarity and 

 symmetry as the effect of a summation of the individual polarities 

 and symmetries of protoplasmic particles or molecules which 

 are definitely oriented with respect to an axis or axes. 



HULL ZOOLOGICAL LABORATORY, 

 UNIVERSITY OF CHICAGO, 

 November, 1910. 



