st 
8 BOTANICAL GAZETTE [JANUARY 
of the products produced on decomposition of the organic sub- 
stances, such as the auximones described by BorromLEy (3) or 
the vitamine water-soluble B, are involved in the germination of 
orchid seeds? Of course other factors may be involved, such as the 
hydrogen ion concentration, mineral salts, or the rate of trans- 
piration, particularly as influencing the organic composition of the 
plant. 
That a full nutrient medium plus sugar is not capable of sustain- 
ing continued growth of higher plants was shown by KNupson and 
Linpstrom (8) in their experiments with albino corn. The plants 
kept either in the light or in the dark and supplied with one of 
several different sugars all died after a month or two. These 
experiments, together with the work of BorToMLEY on auximones, 
the beneficial influence of vegetable extracts on the growth of 
fungi recently described by Duccar (5) and by WiLLaMAN (11), 
and the beneficial influence of vegetable extracts on the growth of 
yeast as described by Witttams (12) and by BACHMANN (1) suggest - 
that more rapid germination and more vigorous plants could be ~ 
obtained if a vegetable extract was added to the nutrient medium. 
With no idea of determining what specific substances are 
involved in stimulating growth, but in the endeavor to develop a 
rapid and effective method for the germination of seeds of certain 
orchids, the experiments described in table I were made. The 
nutrient solution used was solution B. 
The extracts used were prepared as follows. Potato extract: — 
200 gm. of new potato with the skin removed, with 300 cc. of 
distilled water; wheat extract: 200 gm. of air-dried soft wheat, 
with 300 cc. of distilled water; beet extract: 200gm. of a red 
garden beet cut into small pieces, with 200 cc. of distilled water. 
Extraction was made by autoclaving for fifteen minutes at fifteen 
pounds pressure, and the extracts obtained by filtration. The 
yeast juice was obtained as follows: three four-liter flasks, each 
containing three liters of Witi1ams’ solutions, were inoculated 
with a cake of Fleischman’s yeast, and after a week the yeast was 
filtered from the solutions, autolyzed at 37° for twenty-four hours, 
and then dried by suction and washing with ether. Seventy gm. 
of yeast was then steamed for ten minutes with 250 cc. of distilled 
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