Vol. XLIII. November, 1922. No. 5. 



BIOLOGICAL BULLETIN 



STUDIES ON THE CORRELATION BETWEEN META- 

 BOLIC GRADIENTS, ELECTRICAL GRADIENTS, 

 AND GALVANOTAXIS. I. 



L. H. HYMAN AND A. W. BELLAMY, 

 HULL ZOOLOGICAL LABORATORY, UNIVERSITY OF CHICAGO. 



I. INTRODUCTION. 



Several years ago, while investigating the physiology of regen- 

 eration in oligochaetes with the aid of the susceptibility method, 

 the idea occurred to the senior author that there was a remarkable 

 similarity between the susceptibility differences and bioelectric dif- 

 ferences. The points of similarity noticed were the following: 



1. Any injured region or surface is more susceptible to toxic 

 agents than uninjured regions. It has long been known that in- 

 jured regions are electronegative (galvanometrically 1 ) to uninjured 

 ones. 



2. Increase in activity increases the susceptibility and, as is well 

 known, induces an electronegativity (galv.). 



3. There is a susceptibility gradient along the axes of organisms, 

 such that in general the anterior end is the most susceptible and 

 the susceptibility decreases along the principal axis. It was known 

 at that time for a few animals that there is also an electrical 

 gradient along the axis, the anterior end being the most negative 



i It has unfortunately become customary to refer to the bioelectric cur- 

 rents with regard to the direction in which they run in the galvanometer, 

 which is of course the reverse of the direction in the organism. In order 

 to avoid any possibility of confusion with respect to the direction of the 

 current, the abbreviation "galv." in parenthesis will be employed to indicate 

 the direction of the current through the galvanometer, and the abbreviation 

 " int." to indicate the direction of the current through the animal. In all 

 of the tables the designations negative and positive refer to the direction 

 of current with respect to the galvanometer. 



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