1912. 



PUBLIC DOCUMENT — No. 31. 



137 



lu the experiments shown in Table 11. the accelerated growth 

 of the hypocotyl and radicle is somewhat similar to that shown 

 in Table L, namely, the negative charges gave for the hypocotyl 

 12.5 per cent, increase, for the radicle 16.4 per cent., while the 

 positively charged seeds gave 2G per cent, for the hypocotjd and 

 43.42 per cent, for the radicle. Here, too, the positively charged 

 seeds gave the largest average increased growth for both hypo- 

 cotyl and radicle. 



The experiments shown in Tables I. and II. are typical of 

 others made along the same line, althongh we have repeatedly 

 found that it is quite an easy matter to charge the seed too 

 strongly and obtain retardation in growth. Instead of using 

 ten-minute sparks to stimulate the seeds in the electro-germinator 

 we have found by subsequent experiments that it is better to use 

 only two or three, and these should be very slight charges. The 

 stimulating effect of positive and negative charges on germina- 

 tion is similar to that on gro\\i:h, but there is no evidence to show 

 that the treatment affects the germinating capacity of seeds, and 

 we have stimulated many thousands. The following table gives 

 an average of four experiments with seed germination. 



Table III. — Shoiving Results of the Stimulating Effects of Positive and 

 Negative Electrical Charges on Germination of Lettuce Seed (Lactuca 

 saliva, L.). 



[Average of four experiments, 20 seeds being used in each treatment; otherwise the same experi- 

 ments as shown in Tallies I. and II.] 



From the experiments in Table III. it will be observed that 

 germination is accelerated to a considerable degree by electrical 

 stimulation, and that the positive caused greater acceleration 

 than the negative charges, corresponding to the effects produced 

 on the growth of the hypocotyl and radicle. In Fig. 1 is shown 

 a diagrammatic representation of seedlings based upon an aver- 



