200 
E. B. MAINS 
water contained in it, the permeability of the seed coat, and the kind 
of fungus spores on it — all variable factors — have important bearing 
upon the effect of sterilizing solutions upon the seed. It is very un- 
likely that any one solution will work effectively under all combi- 
nations of these conditions. Such a situation means that each worker 
must select the agent which is the best suited to meet the requirements 
of his particular conditions. 
The corn after having been sterilized with HgCl2 was germinated 
in large sterile test tubes. The necessary moisture was maintained 
in the tube by having absorbent paper saturated with distilled water 
in the bottom of the tube when sterilized. The tubes were kept in 
the dark in incubators at a temperature of 27°-30° C. for about seven 
days, at which time the plumule of the corn had attained the height 
of 5-15 cm. 
The endosperm of corn contains a quantity of nutriment which 
can nourish the plant for about a month and in fact when the plant is 
grown in the light, the endosperm often lasts much longer, even two 
months. It is therefore necessary to remove the endosperm before 
placing the plants in nutrient solutions, since it would furnish all the 
plants of the experiment with a large carbohydrate supply. This is 
done by removing the plant from the test tube with sterile forceps 
and making a longitudinal cut through the endosperm down to the 
scutellum. The action of diastase has by this time dissolved away 
the portion of the endosperm lying next to the scutellum and the two 
halves of the endosperm are easily removed with sterile forceps, leaving 
the scutellum surface exposed. The plants are then placed in their 
nutrient solutions. 
The following solutions were used: Cane sugar 15, 12, 6, and 3 
percent; cane sugar 10 and 3 percent plus Knop's mineral nutrient; 
cane sugar 10 percent plus Knop's mineral nutrient minus nitrogen 
(see Experiment 6); starch jelly 15 percent; starch jelly 15 percent 
plus Knop's mineral nutrient; starch jelly 15 percent plus Knop's 
mineral nutrient minus nitrogen ; dextrose 3 percent ; dextrose 3 percent 
plus Knop's mineral nutrient; maltose 3 percent; maltose 3 percent 
plus Knop's mineral nutrient; dextrin 3 percent; dextrin 3 percent plus 
Knop's mineral nutrient; Knop's mineral nutrient; Knop's mineral 
nutrient minus nitrogen ; distilled water. 
Erlenmeyer flasks of 150 cc. capacity were used to contain the 
solutions. These were stoppered with cotton plugs and autoclaved 
