OLDENBUSCH: STIMULATION OF PLANTS 383 
The results of a number of experiments can be summarized 
as follows. After three days, the twigs exposed ten and twenty 
minutes began to develop, the buds showing patches of green 
at the tips. After seven days, the buds on the twigs exposed 
thirty minutes were open considerably. One of the hour experi- 
' ments showed slight greening of the upper buds but other speci- 
mens gave no evidence of development. After nine days, the 
control (not exposed to CS, at all) had two buds developing. 
Twigs exposed ten, twenty and thirty minutes continued to show 
better bud development for two to three weeks longer, after which 
the condition of all tended to become the same. Twigs exposed 
for one and a half hours or for two hours started to open but 
after a day or so became brown and withered, while those 
exposed for four hours or more showed no signs of development 
at any time, indicating that the protoplasm itself must have 
been killed. 
3. STIMULATION OF CERTAIN FUNGI 
As stated above, there has been a vast amount of work done 
on stimulation of fungi by metallic salts and other chemicals. 
Because of this, a number of experiments were set up to test the 
effect of carbon disulphide on fungi. 
To determine the effect of dilute solutions of carbon disulphide 
on the germination of spores of Rhizopus nigricans and Sterig- 
matocystis nigra, hanging drop slides were used. Small glass 
rings were attached to microscope slides by means of a solution 
of dextrin in water (vaseline is not practicable since carbon 
disulphide is very soluble init). The medium used for the ger- 
mination of the spores was prepared according to the following 
formula (see Richards, 4 
Potassium phosphate : 0.5 gm. 
Magnesium ‘oulghate 0.25 gm 
Ammonium nitrate 1.0 gm 
Ferrous sulphate trace 
Sugar 5.0 gms 
Distilled water. ; 100 cc. 
To this was added 5 gms. of gelatine, and the mixture was 
then heated in water bath. When the gelatine was completely 
solved, the medium was filtered tubed (10 cc. to the tube) and 
sterilized. Before the gelatine eon the CS, solution was 
added to make of desired concentrati 
