24 BOTANICAL GAZETTE [JANUARY 
culture employed by both BERNARD and BuRGEFF germination of 
the seeds is dependent on the fungus. There is still considerable — 
work to be done, however, before the validity of the fungus hy- 
pothesis can be proved or disproved. 
Summary 
1. A method is given for sterilizing seeds of certain orchids 
and for growing them under sterile conditions. 
2. Germination of seeds of Laelia, Cattleya, and related forms 
is possible without the aid of any fungus when certain sugars are 
supplied. 
3. Fructose appears more favorable than glucose. 
4. In the presence of glucose, chlorosis of the embryo generally — 
results. ; 
5. Germination is possible on certain plant extracts containing | 
merely traces of sugar. 
6. Embryos in sugar-containing cultures accumulate a consider- — 
able reserve of starch. | 
7. The concentration of glucose is important in the pail of 
the embryo. 
8. Bacillus radicicola from alfalfa and certain other microorgan- — 
isms on certain media have a favorable influence on the develop- — 
ment of chlorophyll and germination. 
g. Seedlings have been transplanted from tubes to large flasks 
and growth has continued. : 
to. The results thus far obtained indicate that the method is : 
of value in the propagation of orchids from seeds. 
11. The idea is advanced that the necessity of fungus infection 
for germination has not yet been proved. . 
12. One cause of failure of germination may be the pathogetie : 
character of some of the endophytic fungi. | 
Mr. T. L. Mean, of Oviedo, Florida, who has worked for many — 
years on the practical problems of germinating orchid seeds, has — 
supplied all the seeds used in these experiments. He has likewise — 
supplied certain information on the practical difficulties and on ~ 
