Dale. — ■ Observations on Gymnoascaceae . 577 
dung, or to beer-wort, or horse-dung extract, made up with 
2 per cent, agar-agar, placed in test-tubes and sloped. In all these 
media the fungus grew well, and produced an abundance of ripe 
ascospores from which other cultures were made. 
The ascospore germinates by the bursting of the outer wall 
and the growing out of the germ-tube (Fig. 2 a-d). The 
germ-tube soon branches close to the spore and becomes 
* septate. Some of the branches grow almost parallel to the 
main axis in one direction, while adjacent ones grow in a com- 
pletely opposite direction (Fig. 2 d). In some cases the 
mycelium branches little, and grows straight on ; and in other 
cases the hyphae branch and curve considerably. In many 
mycelia, but not in all, the hyphal segments are swollen close 
to, and on one side of, each septum. This fact has been pointed 
out by Baranetzky, Brefeld, and others as characteristic of the 
family. Irregular knots of hyphae appeared in a hanging drop 
culture, but came to nothing. Apparently these were patho- 
logical, and due to the starved condition of the mycelium in the 
small drop. Similar irregular masses of hyphae have also been 
observed by Eidam 1 in Ctenomyces , a genus closely allied to 
Gymnoascus, and were by him also regarded as pathological. 
In cultures on horse-dung the mycelium had completed 
its first fructifications, and ripe ascospores were obtained, by 
the first week in July, that is, in about two months from the 
sowing of the spores. 
The vegetative mycelium varies greatly in external appear- 
ance according to the nature of the medium on which it is 
grown. If the fungus is growing on the surface of a dry 
medium, it forms a very small aerial mycelium, which is soft, 
flocculent, and perfectly white (Fig. 3). On it the fructifica- 
tions soon arise as little white bodies which become yellow 
and then brick-red. But if the medium is wet at the surface, 
or if the mycelium is sunk in it, e. g. in gelatine or agar, 
the aerial hyphae cling together in bundles and grow up 
in strands which stand erect and taper to a point (Figs. 4 
1 loc. cit. (1), pp. 286, 287. 
