А STUDY ОҒ THE PHYSIOLOGICAL RELATIONS OF 
SCLEROTINIA CINEREA (BON. SCHROTER 
J. S. COOLEY 
Formerly Rufus J. Lackland Fellow in the Henry Shaw School of Botany of 
Washington University 
INTRODUCTION | 
This paper reports the results of an experimental study regard- , 
ing certain physiological activities of the brown-rot fungus of 4 
stone fruits. The investigation concerns itself primarily with 
the conditions influencing the penetration and infection of 
green and ripe fruits by the fungus in question, the action of 
the parasite on the host cell, and the secretion of the enzymes 
which act upon the cellulose and pectic substances of the host. 
The work was undertaken with the hope of throwing some further 
light upon the factors concerned in fungous parasitism. Our 
present conception of this subject is based upon fragmentary 
and, in some respects, contradictory evidence. However, each 
year there are acquired new facts, or new applications of known 
facts, bearing upon this exceedingly involved and complex 
question. An examination into the history of investigations 
concerning the interaction of host and parasite shows that the 
study of this subject dates back to the work of the pioneers in. . VN T he 
plant pathology ; modern methods and recent discoveries + ve, D 
however, given an added impetus to research along this fine. ~ 
Progress in combating fungous diseases depends | ot | 
upon a familiarity with the life history of the parasite, 
especially upon an intimate knowledge of the metabolism of the 
parasite and the nature of the changes which it induces in the 
host. Indeed, many of our recommendations for controlling 
parasitie diseases of plants will perhaps be modified when a 
more exact knowledge of the interrelations of host and parasite 
is gained. Furthermore, a more intimate knowledge of the 
physiological aspects of plant pathology will undoubtedly throw 
much light on the question of immunity and susceptibility. 
We should, of course, like to know more about the factors 
favoring or inhibiting parasitic action, as well as the conditions 
ANN. Mo. Вот. GARD., Vor. 1, 1914 . (291) 
