OLDENBUSCH: STIMULATION OF PLANTS 379 
I. STIMULATION OF SEEDS AND SEEDLINGS 
The first phase taken up was to determine if there was any 
stimulation of young seedlings by dilute solutions of carbon 
disulphide. Townsend (12, 13, 14) tested the effect of ether 
vapor and hydrogen cyanide gas on different kinds of seeds, by 
soaking seeds in water for twenty-four hours and then putting in 
an airtight dampchamber containing ether vapor. The exposed 
seeds germinated more quickly than unexposed controls, but 
whether left in ether chamber or removed immediately after 
germination, the stimulated seedlings soon lost their advantage, 
and five days after germination the control seeds equaled the 
stimulated in growth. Likewise dry seeds exposed to HCN gas 
for a short time and then soaked in water germinated more 
rapidly than seeds not treated with the hydrogen cyanide. 
However in every case, growth was equal after a week. 
In the following experiments, wheat grains (Triticum sativum) 
were used. One hundred grains were soaked in the CS; solution 
for twenty-four hours. Seed pans were filled with moist sphag- 
num, covered with damp cheese cloth, and grains planted out on 
top of this. They were then covered with a second layer of 
cheese cloth, with a pad of moist sphagnum on top of the whole. 
Pans were kept under a shelf in the greenhouse for three or four 
days, taking care not to allow the sphagnum to dry out. The 
seedlings were then uncovered, epicotyls measured and the 
average taken of those germinated. It was found that the 
saturated solution completely inhibited growth, while the seed- 
lings in the other solutions grew as shown in TABLE I. 
TABLE I 
AVERAGE GROWTH IN MILLIMETERS OF EPICOTYLS OF WHEAT SEEDLINGS AFTER 
BEING SOAKED IN FOLLOWING CS: SOLUTIONS FOR 24 HOURS 
EFT TO GERMINATE FOR 3 OR 4 D 
Series 1. Germinated 4 days 
B 
Exp. A. . be Average Avg. per day 
M/2,000 37-7 37-7 9.4 
M/4,000 39.7 35-2 38.5 37-8 9.4 
M/6,000 40.6 29.2 34-9 8.7 
M/8,000 34.8 31.1 41.3 39-1 9.8 
M/12,000 38.3 34.1 36.2 9.1 
M/16,000 42.7 33-2 37-6 37.8 9.5 
M/22,000 41.2 28.9 43-4 37:8 9-5 
M/32,000 40.0 36.6 39.4 38.7 9.7 
M/40,000 41.5 41.5 10.4 
