Marshall Ward. — On a lily-disease. 363 
developing a mycelium of branched, septate hyphae, which 
form cross-connections, and develop organs of attachment 
so like those already referred to that no one can doubt 
their being organs of the same kind : they are of the tassel- 
form so rare in the lily-fungus, however, and more like those 
formed by the Botrytis on Phaseolus and vegetable marrow, 
than those of the lily-fungus. After forming numerous organs 
of attachment, the Peziza-myceMum, if well nourished, proceeds 
to develop sclerotia on the surface, and in centrifugal order. 
De Bary then goes on to show that his Peziza can be 
cultivated with ease as a saprophyte on many kinds of 
pabulum — wine-must, juices of fruits, and artificial solutions, 
— and that its ordinary mode of life is saprophytic ; but that 
under certain conditions it becomes a parasite, and the most 
remarkable point in his paper is the demonstration of how 
this facultative parasitism comes about. 
As a parasite, it may attack (1) reservoirs of reserve- 
materials, especially carrots and turnips ; (2) the seedlings of 
various dicotyledons ; and (3) the vegetative parts of older 
dicotyledonous plants. He expressly states that in spite of 
all attempts he could not cultivate it, or find it parasitic on 
living monocotyledons. 
It was particularly easy to cultivate the Peziza on carrots 
and turnips, the mycelium forming dense masses on the 
surface and in the tissues, softening them as if they had been 
boiled, and ending in the development of sclerotia. In the 
stems of living plants, the mycelium affects especially the pith 
and cortex, also softening the tissues, and forming sclerotia. 
The hyphae grow especially between the cells, destroying the 
middle lamella and causing the cellulose-walls to gelatinise as 
if boiled. 
But although the mycelium of Sclerotinia (Peziza) Sclero - 
tiorum can thus behave as a parasite, De Bary obtained the 
astonishing result that the germ-hyphae from the ascospores 
cannot directly penetrate into the living plants and that this 
inability to enter living tissues persists until the young mycelium 
has been invigorated by nutrition as a saprophyte . In other 
B b 2 
