AUTHOR S ABSTRACT OF THIS PAPER ISSUED 

 BY THE BIBLIOGRAPHIC SERVICE, NOVEMBER 7 



EXPERIMENTAL CONTROL OF ORGANIC POLARITY 

 BY THE ELECTRIC CURRENT 



I. EFFECTS OF THE ELECTRIC CURRENT ON REGENERATING 

 INTERNODES OF OBELIA COMMISSURALIS 



E. J. LUND 



Puget Sound Marine Biological Laboratory and the Department of Animal Biology, 



University of Minnesota 



THREE FIGURES AND THREE PLATES 



One of the most general properties of living cells and organ- 

 isms is the symmetry and structural polarity which the parts 

 of the individual exhibit. This symmetrical arrangement of 

 parts of the organism generally occurs at the very beginning of 

 development of the individual. The nature of the complex 

 of conditions which determines this structural polarity is one of 

 the fundamental problems of development. 



The majority of biologists would probably agree that the 

 material basis for the structure of the cell or organism is only 

 a result of preceding physicochemical processes, in the same 

 sense that the formation of a precipitate is the result of a chemical 

 or physical reaction, which in turn is always associated with an 

 energy change. If this is correct, it follows that the energy 

 changes or forces which determine the axial or symmetrical 

 arrangement of parts are themselves in some way and to a 

 greater or less degree directed forces. These forces must be 

 assumed to have an axial or polar orientation, corresponding in 

 degree to the axial or polar arrangement of the material affected.^ 



Many different methods of experimental inquiry into this 

 problem have been used, most of which have given suggestive 



' An excellent statement of the problem will be found in Child, CM., Senes- 

 cence and rejuvenescence, pp. 199-202. University of Chicago Press. 



471 



