334 Marshall Ward. — On a lily- disease . 
answer, and perhaps it is scarcely worth while to speculate 
further on so obscure a problem ; but it might be a fair subject 
for inquiry whether the action of the exuding ferment on the 
medium, i. e. food-materials in solution, is not to render the 
latter more directly available, and so mark out a track of least 
resistance as it were ; at the same time it is not easy to see 
how this could happen in a liquid. It might also be asked 
whether the object served by the fusions is to nourish the whole 
mycelium more equably, or to equilibrate certain differences 
which have unavoidably made themselves apparent in the meta- 
bolic processes. In any case, the question at bottom seems to 
be a wide one, and possibly one affecting the particular case of 
reproduction in general. I do not suggest that this is a repro- 
ductive process as usually understood, but it seems probable 
that the stimuli concerned are fundamentally of the same 
nature. 
We may now pass on to consider further cultures of the 
Botrytis, and the development of its conidia and conidiophores 
under conditions which could be controlled. 
I have cultivated it as a saprophyte in the following media 
in addition to the normal Pasteur’s solution, viz. in Pasteur’s 
solution which had been partially exhausted by growing a 
crop of the fungus on it, and then filtered and sterilised ; in 
Pasteur’s solution to which various proportions of peptone 
were added ; in cold water-extract of crushed bulbs of Lilium 
candidum ; in cold water-extract of raisins ; and in certain other 
media which will be described subsequently, such as distilled 
water with bits of lily -bulb, fruit- juices neutralised with 
alkalies, and so forth. 
In all these media the spores germinate, but the free 
development of the mycelium only continues when the liquid 
is acid, and the degree of acidity may be considerable. In a 
distinctly alkaline liquid no germination or growth whatever 
took place. 
In all cases the course of development was the same in 
general, but with differences in detail. Confining attention 
for the present to the cultures in hanging drops, I found that 
