On the Development of the Fructification of 
Armillaria mucida, Schrad. 
BY 
CECIL C. E. FISCHER, 
Indian Forest Service. 
With Plate XXXV. 
A RMILLARIA MUCIDA is a hymenomycetous fungus commonly 
met with in England wherever the beech grows. Its fruit- 
bodies appear in autumn, growing in tufts on the diseased portions of 
beech trees, and are readily identified by the (usually) intense white of the 
pileus, which, further, is covered with a mucilaginous coating. 
The fungus is fairly abundant on the older beech trees in Windsor 
Park, where it seems to be doing considerable harm. 
There appears to be some diversity of opinion as to its true parasitic 
nature, and partly for this reason I undertook a study of its life-history, the 
results of which will be embodied in a separate paper. The opportunity for 
tracing the course of the development of the fructification naturally pre- 
sented itself, and this forms the subject of the present note. 
Comparatively little attention has been given to the development of the 
fructification in Hymenomycetes. One of the most recent papers on the 
subject is that of G. F. Atkinson on Agaricus campestris ( 1 ), in 1906. 
Prior to this paper no detailed study of the development appears to have 
been made since Fayod’s work ( 3 ) in 1889. 
Atkinson gives an historical sketch of previous work in this direction in 
the paper quoted above ; consequently no lengthy resume need be given 
here. 
Atkinson suggests, apparently with justification, that the earlier 
investigators did not examine sufficiently young specimens, and they seem 
to have been led to general conclusions which do not hold good at any rate 
in all cases. 
De Bary in the case of Agaricus campestris ( 2 ) and R. Hartig in that of 
Armillaria (Agaricus) mellea ( 5 ) describe the veil (velum partiale of Fries) 
as developing by new growth. They find that at an early stage a circular 
[Annals of Botany, Vol. XXIII. No. XCI. July, 1909.] 
M m 
