6 BOTANICAL GAZETTE [JANUARY 
This was repeated several times, since the seeds generally float 
together in a mass at the surface of the liquid. The period of 
exposure was about fifteen minutes, although in some preliminary 
experiments with seeds of Cattleya and Laelia no injury was noted 
after a three hours’ exposure. The seeds were transferred from 
the sterilizing solution, without any previous rinsing in water, by 
the use of a platinum needle. With the small loop used, it 
was possible to pick up about 100 seeds. These were scattered 
over the surface of the agar slope. The cultures were maintained 
in moist chambers in the greenhouse shaded by cheesecloth from 
direct sunlight, with the temperature between 15° and 35°C. In 
determining growth, the embryos were measured by means of an 
ocular micrometer. As was shown by both BERNARD and BurGEFF, 
the width of the embryo or the protocorm may be accepted as a 
good criterion of the degree of growth. Other data are included, 
such as percentage of germination, time of formation of first leaf, 
color, starch content, etc. 
Preliminary experiments 
EXPERIMENT 1.—On December 7, 1918, seeds of Cattleya 
Schroederae XC. gigas were sterilized by treating them for two 
hours with the calcium hypochlorite solution. The seeds were 
sown on agar slopes. The medium used in one case was an extract 
of peat, made by autoclaving 300 gm. of bog peat, such as is used 
for potting orchids, with 1200 cc. of tap water. This was filtered 
and the clear brownish filtrate used. The other medium was made 
by autoclaving 400 gm. of dormant canna tubers with 600 cc. of : 
water for thirty minutes. By January. 7, 1918, the seeds on both 
were in the small spherule stage and were green. On April 10, 
four months after planting, the seeds on the canna medium had 
germinated, the seedlings having one and two leaves. On the 
peat agar medium the embryos-were a little larger than on January 
7, 1919, but not significantly different. 
XPERIMENT 2.—The media used were extracts of carrot and 
garden beet. The carrot extract was made by autoclaving 70 gm. 
of young carrots (root) with 75 cc. of tap water, and the garden 
beet extract was made by autoclaving 50 gm. of young beets (root) 
