146 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
number of species, but only in Tomentella and in Poly poms annosus 
are regularly occurring and well differentiated conidia known to exist. 
Culture Methods. 
The germinating basidiospore was the starting point of every cul¬ 
ture used in the present investigation. In many instances pure cul¬ 
tures were obtained in other ways, as by transferring with a sterile 
knife a bit of the subhymenium to the culture medium, but such cul¬ 
tures were employed merely as checks, and were never made the basis 
of extensive experiments. The basidiospore was regarded as the 
most logical point of departure in culture study, and the possibility of 
error was less than though the culture was obtained in some other 
way; moreover, it was thought that the young mycelium arising from 
the basidiospore might possess properties and means of reproduction 
not seen in the more mature stages of the fungus. 
To obtain the basidiospores, specimens of the fungus with fresh 
hymenia were collected in the field, carefully wrapped in clean paper 
or placed in sterile boxes and brought as quickly as possible into the 
laboratory. The fructification, with hymenium turned downward, 
was suspended over a sterile plate on which were lying sterilized slips 
of mica. The whole was covered with a bell jar in order to prevent 
the entrance of foreign spores, and to ensure a moist atmosphere 
suitable for the continued development of basidiospores. After a 
considerable number of spores had been deposited on the mica, the 
slips were removed and placed in sterile vials stopped with cotton plugs. 
When the cultures were made a tiny drop of water was placed upon 
the mica slip in the vial, and the spores, loosened from the mica, 
could then be removed with a platinum needle. 
The basidiospores of many species retain the power of germination 
but a short time, especially when dry; hence cultures were made 
immediately from the spores on the mica. Carefully sealed Van 
Tieghem cells were used in which were placed hanging drops of a 
weak decoction of some fresh vegetable, dried fruit, etc., rendered 
solid by agar-agar. All materials and instruments employed in the 
construction of these cells were carefully sterilized. No extensive 
experiments were conducted to secure the germination of refractory 
spores, but attention was given to those species whose spores germi¬ 
nated readily under ordinary culture conditions. 
