376 BOTANICAL GAZETTE [NOVEMBER 
from the stimulation period than in this case, where very weak charges 
were used. A charge of one or two minute sparks from a Leyden 
jar seemed to cause the most active response on the part of the yeast. 
| | 
an eee: 
vw [ 
25 j 
SIT 
[ 
20 
[ ete 
/ 
15 papel 
[ ea 
[ Eales 
] wae 
10 4 ee 
iV = y faa 
fel ve HB Be 
y SS 
5 J] A ASEES 
ha : +-—+-—} = 
Ss Se tI 
0 
115 30 _45 2.00 1s. 30 4s 3.00 1s 30 a5 4.00 15 30 
Fic. 2.—Curve representing the amount of CO, given off by electrically stimulated 
yeast; the potlecatal lines represent the amount of carbon dioxid in cubic ce entimeters; 
the vertical lines five-minute periods of observation; S, time stimulation was appl lied 
(1:50 P. M.); M, maximum effect of stimulus. 
Discussion of results 
In considering the results presented here it should be pointed out 
that little attempt was made to ascertain the strength of the current 
necessary to produce the best results, and the static charges employed 
differed in number and intensity. We have already demonstrated 
in a large series of experiments* with the higher plants that the opti- 
mum current for germination of seeds and growth of seedlings is not 
far from o.1 milliampere, and in our study of the effect of static 
4 Stone, G. E., The influence of current electricity on plant anne Ann. Rep. 
Hatch Exper. Sta. Nine Agric. Coll. 16: 13-31. 
