SSS 
LIBERATION OF OrGANIC MaTrer BY Roots of GRowinG Puants 15 
SEED STERILIZATION 
Seeds were rendered sterile by the calcium hypochlorite method as 
employed by Wilson (1915). After disinfection the seeds were planted 
on a sterile medium, from which, 
after germination, the plants 
were transferred to the perma- 
nent position. The solid medium 
for the germination was usually 
composed of the same ingredients 
as were used in the large con- 
tainers, from which the plants 
eventually drew their nutrients, 
with from 1 to 1.5 per cent of 
agar. The agar was used in 
order that contaminations might 
be detected before the plants 
were transferred to their perma- 
nent position. This medium was 
made in sufficient quantity to 
meet the requirements and was 
distributed into large test tubes. 
Since the roots of most plant- 
lets spread out in a lateral direc- 
tion, thus making it difficult to 
transplant them quickly and con- 
veniently, some device was 
needed which would direct the 
root growth in a vertical direc- 
tion. To accomplish this there 
was placed in each test tube a 
short piece of glass tubing, 25 by 
50 millimeters in size (fig. 1, e). 
A sufficient quantity of the 
medium was put into the tube to 
cover all but about 15 millimeters 
of this glass tubing. After ster- 
\ 
(4 Rd (thts | 
Se tk 
ole cl le 
e@ eel Vi a 7 
Fig. 1. DEVICE FOR GROWING LARGE PLANTS IN 
STERILE MEDIA 
a, Cheesecloth; 6, cotton wool; c, outside tube into 
which e slides; d, agar carried over from test tube with 
plantlet; e, tube in which seed germinates 
ilization of the medium the sterile seeds were dropped onto it, where they 
germinated and produced rootlets for subsequent use. When the roots 
