Frutt-bodies of Coprinus comatus in Laboratory Cultures. 223 
forth. Such a series of transfers I made with a mycelium of 
Coprinus comatus. A stipe-culture was growing on sterilised 
horse-dung balls contained in a crystallising dish five inches in 
diameter. As soon as the mycelium had covered the medium, 
a small piece of mycelium-covered dung was removed and placed 
in a second similar dung-dish. Four such successive transfers 
were made and it was found that it took the mycelium 10-11 
days to cover the medium in each dish. Although all the four 
cultures were maintained for months, no fruit-bodies were pro- 
duced upon them; yet the mycelia were vigorous and, as shown 
by their abundant clamp-connections, they were all secondary, 
i.e. in that sexual condition which the mycelia of Hymeno- 
mycetes normally attain before the development of sporophores 
takes place*. 
Finally, at the suggestion of Professor Buller, deep culture 
vessels, instead of shallow ones, were employed, and the culture 
medium was covered with a thick layer of soil. Two such deep 
cultures were made in the following manner: (1) A specimen 
jar 11 inches high and 3 inches in diameter was filled to a depth 
of 3 inches with a layer of horse dung mixed with sawdust. The 
mixture was packed down and then the jar was filled to within 
an inch of the top with sifted black soil. The whole was then 
covered with a glass plate and sterilised in flowing steam for 
one hour on each of three successive days. After sterilisation 
had been accomplished, two vertical holes were made through 
the six-inch layer of soil with a sterilised glass rod, and through 
these holes small pieces of mycelium-covered dung taken from 
a stipe-culture were pushed well down into the layer of dung 
and sawdust below. (2) A three-litre beaker was filled to within 
three inches of the top with a mixture of horse dung and sawdust 
resembling that used for the first culture. After being packed 
down, the mixture was covered with a two-inch layer of sifted 
black soil. The beaker and its contents were then sterilised and 
the culture-medium inoculated in the manner already described. 
The inoculation of the culture medium in the two vessels was 
effected on January 7, 1921. After inoculation, both vessels 
were set on a table near a window in the laboratory and each 
was covered with a large bell-jar. The loose glass plate resting 
on the top of each vessel and the enveloping bell-jars served to 
reduce the rate of evaporation from the surface of the soil to a 
minimum. Indeed, evaporation took place so slowly that it was 
found unnecessary to water the cultures during the ten months 
which elapsed before they fruited. 
* Cf. I. Mounce, Homothallism and the Production of Fruit-bodies by Mono- 
sporous Mycelia in the Genus Coprinus, Trans. Brit. Myc. Soc. vi, 1921, 
pp. 198-200. 
