LYMAN: STUDIES OF HYMENOMYCETES. 
147 
Brefeld has rightly insisted that every culture should be begun with 
the germination of a single spore. To secure this end, the writer 
transferred a few spores with a platinum needle from the mica slip to 
a drop of sterile water, where they were diluted sufficiently so that a 
single spore could, in the course of several attempts, be carried on the 
point of a needle to the hanging drop in the culture cell. Almost 
insuperable difficulty was experienced in this operation in the case of 
species with extremely minute and colorless spores, for even careful 
microscopic examination of the hanging drop failed to demonstrate 
with certainty the number of spores present; such spores commonly 
enlarged greatly on germination, however, and thus became clearly 
visible. 
Inasmuch as the percentage of germination in most species is low, 
at least considerably below 100 percent, it will be seen that, a large 
proportion of the cells thus laboriously made showed no growth. 
Hence, to reduce the amount of unproductive labor, a preliminary 
test was made, using a culture cell in which many spores were sown. 
Then other cells were made containing few spores,—- the approximate 
number depending upon the percentage of germination shown by the 
first cell; the spores in each cell were carefully examined and identi¬ 
fied so far as possible as belonging to the species in hand. All cells 
showing the germination of more than one spore were discarded. In 
case but one spore germinated, the growth was carefully watched until 
the hyphae had spread out beyond the ungerminated spores when a 
bit of the mycelium-bearing agar was transferred to a new drop cul¬ 
ture. In this way pure cultures were secured. In the case of species 
which proved to be of especial interest, however, pains were taken to 
secure the germination of isolated spores, and the discussion in the 
following pages is based upon cultures thus obtained. The danger 
of error was reduced by carrying numerous cultures as checks, and all 
important results were verified by cultures obtained from later collec¬ 
tions of the basidio-fructifications in the field. 
From the hanging drop, bits of mycelium were taken to start cul¬ 
tures in test tubes and jars upon nutrient agar, and sterilized wood, 
vegetables, etc. In the majority of species studied the writer was able 
with more or less difficulty to raise basidiosporic hymenia in the labo¬ 
ratory, thus completing the life cycle, and giving a supply of basidio- 
spores of unquestioned purity for further experiments. All the more 
important species discussed in this paper have been kept under culti- 
