1900] BOTRYTIS AND SCLEROTINIA 405 
organs of attachment abundantly when in contact with ‘any hard 
substance. Sclerotia are always produced abundantly in cultures 
and upon affected plants. These vary in size up to an inch in 
length, having an irregular form, but are solid and “meaty” and 
produced embedded in the mycelium, having no connection what- — 
ever with the substratum. The Peziza form is readily obtained 
from them. The internal structure of these sclerotia consists 
of a mass of thickened filaments knotted closely together and 
surrounded by a black, cellular layer. This species is a typical 
example of a facultative parasite, being able to exist indefinitely 
as a Saprophyte but at the same time capable of attacking a 
great variety of plants in a strictly parasitic manner. ~ 
Botrytis cinerea is without doubt a closely related species, and 
has many points of resemblance. It is not as strongly para- 
sitic as the other species, attacking living plants more commonly 
only when they are under unfavorable conditions or when injured 
insome way. At times, however, it appears to be a true para- 
site. When growing as a saprophyte it has no particular resem- 
blance to Sc/. Libertiand under the same conditions, producing 
much less mycelium and a great abundance of conidia. When 
Stowing as a parasite it is in some respects indistinguishable from 
the other species. The mycelium is entirely similar and organs 
of attachment are produced which are likewise exactly the same. 
The effect upon the plant is often entirely similar. As a para- 
Site.it appears to produce fewer conidia in proportion to the 
degree of parasitism. Often in newly affected tissue none 
appear. Sclerotia are often produced in cultures and on affected 
plants but with considerable uncertainty. Not rarely cultures 
made from conidia produce no spores whatever, but numerous 
Sclerotia. This is most common when parasitic material is 
used, The sclerotia are highly characteristic and suffice at all 
times to distinguish this species from the other. They usually 
have a narrow form, especially in tube cultures, and bbs 4, 
thin and inseparably attached to the substratum, lacking entirely 
the definite form and the solid, “meaty” structure of the 
Sclerotia of Sc/. Libertiana. So far as known no Peziza has ever 
