526 Fischer . — The Biology of Armillaria mucida , Schrader. 
resupinate forms of Armillaria mucida . Abnormalities of this nature are 
not altogether unknown in the case of other fungi. 
It must be remembered that the inoculation was made from a culture 
that never showed any trace of impurity and produced normal carpophores, 
proving its identity. Also, the daughter-culture under consideration pro- 
duced a mycelium of normal appearance, and on one part of it incipient 
fruit bodies which entirely resembled those of A. mucida appeared, though 
they failed to mature. Unfortunately, I was unable to separate out the 
spores from the abnormal fructifications so as to germinate them, nor could 
I obtain vegetative growth from pieces of the fructification in separate 
cultures. 
In the normal carpophores it was observed that, as laid down by 
Fayod ( 7 ), the spore does not arise apically on the sterigma, but somewhat 
laterally, and only assumes the central position later on as it approaches 
maturity (Fig. 29 a , b, c). 
Inoculations. 
The experiments carried out to test for parasitic habit were of two 
descriptions : on living trees in the open and on living and dead twigs in 
the laboratory. 
On November 27 a healthy branch about 2-J inches in diameter was 
selected on a sound beech tree, and two holes some eight inches apart were 
bored to its centre with a centre-bit, which had been previously sterilized by 
dipping it first in corrosive sublimate and then in absolute alcohol. Spores 
taken from a carpophore obtained in the neighbourhood were placed in one 
of the bore-holes only, the other being left intact. Both holes were closed 
with grafting-wax. A little further along the same branch a small wound 
just exposing the wood was made and was also infected with spores, and 
similarly occluded with wax. The branch was cut off on April 17, on 
which date it was quite healthy and full of sap. No infection had taken 
place at either of the points at which the spores had been placed. Spores 
were still adhering in a mass to the surfaces of the wounds ; most had not 
even germinated, and those germ-tubes that had appeared had failed to 
effect an entry into the wood. The section of wood containing the inoculated 
bore-hole was put in a damp vessel on April 19. By June 5 it was found 
that hyphae had penetrated about 50 ju into the tissues, which though now 
dead were still full of moisture. The block was then placed in a dry jar. 
Sixteen days later, the wood being then comparatively dry, it was ascer- 
tained that the hyphae had penetrated much deeper and were far more 
abundant. 
On January 11 two further inoculations were made on living beech 
trees. One rather slender branch on each of two healthy trees was picked 
out. In each case a twig was broken off so as to leave a jagged surface, 
