86 
Journal of Agricultural Research 
Vol. XXIII, No. s 
samples—was sterilized for five minutes in a i per cent solution of silver 
nitrate 4 with subsequent, thorough washing. Concurrent comparative 
germination tests of a number of samples with and without previous 
sterilization of the grain showed that the sterilization had no effect upon 
germination except to increase that of grain which molded badly without 
such sterilization. 
Additional trials showed that wheat with not more than io to 12 per 
cent moisture could, with impunity, be immersed two minutes in a 1 per 
cent silver-nitrate solution even after cutting off the distal end, provided 
that the washing was very thorough. The cut surfaces of the endosperm 
subsequently darkened but germination did not suffer. A small per¬ 
centage germinated even after the embryo had been scratched with a 
needle followed by two minutes in 1 per cent silver nitrate and thorough 
washing. Of course, a majority of the grains thus treated could not 
escape serious injury. This would be the case also with grains cracked 
or mutilated by thrashing or handling. 
INFLUENCE OF THE SEED BED UPON GERMINATION 
The result of the imbibition experiments and of the germination tests 
after presoaking suggested an attempt to secure by the use of a suitable 
germinating bed as much as possible of the accelerating effects of the 
presoak without its undesirable effects upon germinating capacity. 
Trials were therefore made in 100-mm. Petri dishes with one rather 
poorly germinating sample each of wheat, barley, and oats, using seed 
beds of different character and moisture content. 
For seed bed the following were used: (1) Four circular disks of heavy 
blue blotting paper; (2) raw cotton of low absorbing capacity; (3) 
Johnson & Johnson absorbent cotton. When blotting paper disks were 
used the grain was tested both on top of the four disks and between the 
second and third disks. 
Four blotting paper disks weighed from 7^ to 8 gm. It required from 
12 to 1^% cc. of water to saturate them and then 1 cc. additional made 
sufficient excess to drip when the uncovered Petri dishes were a little 
more than half inverted. This additional amount of water was all 
absorbed by the blotters in the next two or three hours. For the germi¬ 
nation tests between blotters just the amount of water required to satu¬ 
rate the blotters was used in each case. For the germination tests on 
top of the blotters 1 cc. was added. 
The Johnson & Johnson absorbent cotton in each dish weighed only 
1.8 gr. (less than one-fourth as much as the blotters) and was saturated, 
when firmly pressed down, with 11 cc. of water. The addition of 6 cc. 
of water was then not sufficient to allow any to drip when the uncovered 
dish was a little more than half inverted. Thus the water-holding 
capacity of the absorbent cotton was greater than that of four times as 
great weight of the blotters; and of this large amount of water held by 
the cotton without flooding the seeds five or six times as much was 
readily available for rapid absorption by the seeds. 
In the germination tests the amount of water required to saturate the 
cotton (11 cc.) was used in comparison with other tests using 2 cc. less 
and 6 cc. more water. 
4 A solution of silver nitrate is a very, desirable medium for surface sterilization on account of the ease 
with which it can be removed or precipitated as the chlorid, the tenacity with which the silver chlorid is 
held on the coat structures, and the consequent relatively permanent sterility conferred. 
