THE EFFECT OF ELECTRICAL STIMULATION UPON 
THE RATE OF REGENERATION IN RANA PIPIENS 
AND AMBLYSTOMA JEFFERSONIANUM! 
BY 
OREN E. FRAZEE 
Witu Two Ficures 
INTRODUCTION 
The object of the experiment was the determination of the 
effect of electrical stimulation upon the rate of regeneration. 
Larve of Rana pipiens and Amblystoma jeffersonianum were 
used. ‘These forms were selected because of their abundance, 
and because of the work which has already been done upon 
their regeneration. 
METHODS 
The general method consisted of the selection of a number of 
individuals divided into two equal sets,? one of which was to be 
stimulated, and the other not stimulated. An effort was made 
to have like conditions at all times for both the stimulated and 
the non-stimulated individuals. ‘The food, light, temperature and 
handling are among the factors which were regarded as impor- 
tant to control. ‘The factor of age is another important one in 
its bearing upon the rate of regeneration. For this reason, ani- 
mals of the same age were selected. 
The tadpoles were kept in small berry dishes. Cleanliness was 
emphasized and the dishes were cleaned thoroughly daily. Thin 
glass covers were placed over the dishes about 5 mm. above the 
1 Contribution from the Zodlogical Laboratory of Indiana University, No. 107. 
? See the various experiments for the modifications of the method of applying the current. 
Tue JourNAL or ExPERIMENTAL Zod.ocy, VOL. VII, NO. 3. 
