434 B idler. — The Reactions of the Fruit- Bo dies of 
In twenty-four hours a white deposit of spores was formed on the paper. 
Practically all the spores had fallen during that time. The block bearing 
the other half of the fruit-body was placed under a bell-jar, the atmosphere 
of which was saturated with water-vapour. Black paper was laid beneath 
the fruit-body. No spores were deposited for a week. At the end of that 
period the air in the bell-jar had become relatively dry. Spores then began 
to fall, and a white deposit accumulated on the paper. It is evident from 
the experiment that when the air is moist, the spores do not separate 
so soon from the basidia as when the air is dry. The oecological advantage 
of this is obvious. In dry weather there will be no more chance of the 
spores being scattered than in wet weather. The fall of the spores, there- 
fore, is arranged to take place when the atmosphere is dry and is hindered 
by its saturation with water-vapour. 
It was found that some of the fruit-bodies grown in a weak light 
became branched. Cooke has figured a large branched monstrosity in his 
Illustrations of the British Fungi, PL 1141. Branching seems to be fre- 
quently induced by the formation of abortive pilei. A rod was often 
observed to grow slowly without branching in weak light and then to form 
a small pileus, which did not develop its gills fully, and which soon became 
abortive. Branching then took place. In some cases the branches arose 
from the edges of the pileus (Figs. 28 and 29). After a time the branches 
developed more abortive pilei (Fig. 29). One monstrosity even produced 
primary, secondary, and tertiary stipes and primary, secondary, and tertiary 
abortive pilei (Fig. 28). 
Branching may also take place from the stipe. A fruit-body produced 
a small pileus at the end of a stipe three inches long. After the withering 
of the pileus about twenty branches grew out from the stipe simultaneously. 
Some of the gills also produced tiny outgrowths on their edges, which had 
the appearance of abortive pilei, although no gills were developed on them. 
The young pileus of another fruit-body (Fig. 27) became injured by being 
pressed against the glass wall of the damp-chamber. The pileus ceased to 
develop and several branches arose on the stipe. 
I pinched off the ends of a number of rods upon which pilei had 
not been formed. A new growing point was developed at the end of each 
rod, but the injury did not induce any branching. 
Two out of a considerable number of rods, grown entirely in the dark, 
each developed a very short lateral branch. In these two instances branch- 
ing appeared to be due to internal causes, for the rods had grown apparently 
without injury under very constant conditions. A branched monstrosity 
looking very much like an elk’s horn I found growing out of a block, which 
with others had been removed from a street and piled up at a wharf 
(Fig. 18). 
From the observations recorded in this paper it is evident that the 
