BIOLOGY OF COLLYBIA VELUTIPES. 119 
stage. Further, Hoffmann * has traced the development of the 
sporophore. Reference will be made to these papers in more 
detail later. 
The method of culture adopted was as follows :— Ripe sporo- 
phores of the fungus were placed with the gills downward in 
clean, covered watch-glasses, and some of the spores deposited 
transferred with a sterile needle to tubes of gelatine, containing 
from one to two per cent. of cane-sugar, from which drop-cultures 
and plates were prepared t. 
The early stages of germination were followed in hanging-drops 
under the mieroscope. In 24 hours at a temperature of 17? C. 
the first hyphx appear; they branch and grow rapidly for seven 
days, forming a tangled septate mycelium, which then becomes 
very vacuolated, and on the eighth day the ends of its hyphx 
begin to septate off to form oidia. Iu another day practically the 
whole mycelium has broken up into oidia-chains (Pl. 2. fig. 1). 
The oidia are rod-shaped, with slightly rounded ends. They vary 
considerably in length, 3-85 p being the extreme measurements 
obtained, while their breadth of 2 is fairly constant. Each 
contains a distinct nucleus. 
No further changes were found to occur in these hanging-drops, 
although kept under observation until they became dried up. 
Meanwhile, a similar development occurred in the plate eultures, 
and oidia from them were transferred to blocks of sterilized horsc- 
chestnut wood, placed in large, plugged test-tubes, and kept 
moist with cotton-wool saturated with water. The sterilization 
was effected by heating the tubes containing. the blocks, and the 
cotton-wool plugs in a steam-sterilizer for an hour, half an hour, 
and quarter of an hour, on three successive days. Three days 
after infection a slight mycelium is visible to the naked eye, 
which spreads gradually, and in a few weeks forms a thin, mealy 
layer over the whole surface of the block. A month after infec- 
tion (Jan. 31st., March 1st) the sporophores are obtained. The 
mycelium at the point of formation turns an umber-brown colour, 
and in the centre of the patch a small rounded body 0:5-1 mm. 
in diameter appears, from which sporophores rapidly develop. 
These small, rounded bodies represent the sclerotia found in 
other species of Collybia, e. g. C. tuberosa, P. Karst. A distinet 
* Hoffmann, in de Bary’s Comp. Morph. & Biol. of Fungi, ete. p. 297, 
t See Marshall Ward, Phil, Trans. 1897, vol. 189. P, p. 123, 
M 2 
