Bulgaria polymorpha , Well. 123 
mycelium on the blocks, I assume that the mycelium from 
the ascospore is capable of direct infection. 
To study the action of the Fungus on wood, sterile blocks 
of oak and pine-wood were infected from plate-cultures of 
the ascospores, beer-wort gelatine being used for germinating 
them in. A week after infecting the blocks it was evident 
that the Fungus was growing satisfactorily, for the greater 
part of their surfaces was covered with a thin, tawny yellow 
felt of mycelium, which had further commenced to spread 
over the damp cotton-wool plugs on which they rested. 
The cultures on pine-wood went no further than this, but 
on the oak-wood the mycelium increased in quantity, turned 
to a darker brownish-yellow colour, and in three weeks’ time 
small white humps of tissue appeared on them which gradually 
increased in size and at the same time exuded drops of 
water (Fig. 2 ). This secretion of water usually appears to 
occur when a Fungus is growing rapidly or is making some 
special effort, as for instance when spores are being pro- 
duced. As a familiar case I may mention Polyporus hispidus , 
Fr., which while forming its basidiospores exudes quarts of 
water. The phenomenon is more readily observed in tube- 
cultures, where evaporation is not so rapid as in the open. 
It is probably due to the necessity for large supplies of food- 
stuff, which have to be taken up in solution and the excess 
of water disposed of. 
The development of these white humps proceeded slowly, 
and it was not until three months had passed that they 
appeared as the more or less scurfy, gelatinous knobs char- 
acteristic of the young ascophores. Externally their appear- 
ance was somewhat variable, some were light grey-brown in 
colour, others deep chestnut or even black. Those growing 
from the cotton-wool plugs were usually darkest in colour 
and had a sodden gelatinous appearance. Then the polished 
black hymenium opened out and in a few days shed its 
ascospores as a sooty-brown deposit on the sides of the 
tubes. 
Cultures were fixed either by boiling, or with 20°/ 0 alcohol, 
