Effect of Electrical Stimulation 463 
Experiment 7. For this experiment 80 larve of Amblystoma 
jeffersonianum were selected. They were measured and operated 
upon March 12, 1909. Forty were stimulated March 15, 1909, 
for six minutes. Current density 10 6. Voltage 110. Measure- 
ments of the amount regenerated were taken March 17, 19, 21, 
and 23, 1909. 
Those numbered 1-5, 11-16, 21-26, etc., are individuals of 
the non-stimulated set; those numbered 6-10, 16-20, 26-30, etc., 
are members of the stimulated set. 
Tables V, VI and VII give all the measurements taken during 
the experiment. 
An examination of these measurements shows: 
1 That two days after the stimulation each individual of the 
stimulated set had regenerated on the average 0.044 + mm., or 
nearly 5 per cent more than the members of the non-stimulated 
set. See Tables V and VI, measurement number one. 
2 That four days after the stimulation each individual of the 
stimulated set had regenerated on the average 0.063 + mm., or 
nearly 4 per cent more than the members of the non-stimulated 
set. See Tables V and VI, measurement number two. 
3 That six days after the stimulation each individual of the 
stimulated set had regenerated on the average 0.06 + mm., or 
2.6 + per cent more than the members of the non-stimulated set. 
See Tables V and VI, measurement number three. 
4 That eight days after the stimulation each individual of the 
stimulated set had regenerated on the average 0.086+ mm., or 
nearly 22 per cent more than the members of the non-stimulated 
set. See Tables V and VI, measurement number four. 
5 That 40 days after the beginning of the operation, each 
individual of the stimulated set had a greater total length on the 
average of 1.036 + mm.,or 10 + per cent more than the individuals 
of the non-stimulated set, although their average total lengths 
at the beginning were the same. ‘This shows that the stimulation 
increased the rate of general growth of the animal as well as 
its rate of regeneration. See Table VII. 
Experiment 8. This experiment included 34 larve of Ambly- 
stoma jeffersonianum ranging from 23.5 to 31 mm. in length. 
4 See measurements, Tables V, VI, and Table VII. 
