(in h, 1923 Forcing the Germination of Freshly Harvested Wheat 83 
“ heat stimulus, ” which he makes the basis upon which rests the beneficial 
results of both drying and presoaking. With water as the heating 
medium and the grain therefore in a sensitive condition the heat stimulus 
is felt in a few hours, whereas in dry condition days are required. Too 
long heating (overstimulation according to Kiessling ( 28 ), is of course 
harmful. Moufang' and Vetter (35) therefore recommended soaking 
barley one hour at 45 0 C., followed by soaking in the cold in preparing 
it for malting. Too long-continued soaking at any temperature also is 
recognized as harmful by all who have worked upon the subject, and 
Wollny (45), Kidd and West (27), and others have emphasized the fact 
that harmful effects result from presoaking in an excess of standing water. 
This danger is reduced by using running water. According to Kidd and 
West (27), presoaking the red dwarf bean in excess of water increased 
the rate and vigor of germination but decreased the total percentage 
germinating and the number and dry weight of the seedlings which 
survived after three weeks in good soil. The injury thus measured and 
the amount of exosmosis from the seeds while soaking was greater when 
they were soaked at 5 0 to io° C. or at 30° C. than when soaked at 20° C. 
Braun (ro) has recently described in connection with the treatment 
of cereals for seed-borne diseases a successful method of presoaking 
which is said to stimulate germination and early growth at the same 
time that it increases the efficiency of the sterilization treatments. 
Braun used a minimum quantity of water and limited the soaking time. 
Wollny (45), Kraus (31), and Hiltner ( 21 ) reached conflicting con¬ 
clusions, which Eberhart (16) attempted to harmonize, as to the effects 
of presoaking cereals and other seeds upon the resulting crop yield. All 
these except Hiltner ( 21) agreed that presoaking under certain condi¬ 
tions has a very marked effect in increasing crop yield. The seeds were 
sometimes sowed moist and sometimes after a period of drying, which 
did not seem to destroy the beneficial effects. Characteristic differences 
were observed at different stages of development between the plants 
from the controls and those from the treated seeds. Wollny (45) attrib¬ 
uted the effects to coat changes which allow a more rapid water intake 
and initiate a more vigorous growth, though the percentage germinating 
is usually lessened, as Kraus (31) also decided. Eberhart (16) agreed 
that the permeability of the seed coats to water is increased by the pre¬ 
soaking as also by favoring ether treatments and that this increase is 
important; but he concluded that protoplasmic alterations also must 
be involved, since the effect is not temporary but persists throughout 
the growing period. 
As already stated, the majority of the germination tests in this investi¬ 
gation were made after soaking the grain about one-half hour in running 
water. The grains to be tested for germination were placed in the bot¬ 
toms of Gooch crucibles, which were then stacked in columns of not more 
than 12 in ring-stand supports. Tap water at approximately 18 0 C. 
from a spigot which gave a spattering stream, so that the water must 
have been well charged with atmospheric air as it bathed the grain, was 
then allowed to run through the entire columns. The object of this pre¬ 
soaking was to wash the seeds as free as possible of microorganisms and 
also to remove or precipitate (by means of chlorids in the water) the silver 
nitrate remaining on the grain in those tests in which the grain had been 
sterilized. There is no reason to believe that there were any harmful 
effects from this treatment. 
