1914) 
COOLEY—SCLEROTINIA CINEREA 295 
different sources. He claims that these fungi act differently 
toward different celluloses, dissolving some and having no effect 
on others. The nature of the penetration and the action of 
certain parasites on the host tissue were also studied. There 
was no case in which Botrytis dissolved true cellulose, but it 
readily dissolved the hemicellulose part of the cell, leaving the 
cellulose intact. According to this author, therefore, the pene- 
tration and dissolving action of such parasites as Botrytis vul- 
garis is due to their ability to dissolve hemicelluloses. Не 
considers that the middle lamella is largely composed of hemi- 
celluloses or closely allied substances. According to this view, 
therefore, organisms that dissolve the middle lamella are essen- 
tially hemicellulose-dissolving forms. As a result of his studies 
on Sclerotinia fructigena and S. cinerea, Schellenberg finds a 
different action on different fruits, but in no case does he report 
a splitting of the cells along the line of the middle lamella, as 
some previous investigators have reported. He believes that 
there is a slight dissolving action on that part of the cell wall 
which is in immediate contact with the fungous filament, but 
that the rest of the cell wall remains intact. In the twigs also 
he finds that the fungus dissolves the hemicellulose and leaves 
the true cellulose unacted upon. 
An extensive literature has developed concerning the enzymes 
of importance in the nutrition of fungi, but since these investi- 
gations either deal with saprophytes, or are only indirectly 
concerned with the work to be reported in this paper, it will be 
unnecessary to do more than mention some of the papers here. 
Among the more important contributors may be mentioned 
Ward (50, 52), who was the first to use pure cultures of a wood- 
destroying fungus (Stereum), Biffen (9), who studied the biology 
of Bulgaria polymorpha, Bourquelot and Hérissey (13), who in- 
vestigated the enzymes in sporophores of Polyporus sulphureus, 
Czapek (18), who made his investigations with natural infections 
of Merulius lacrymans and with other fungi, Kohnstamm (33), 
who worked on some species of Merulius, Buller (14, 15), who in- 
vestigated sporophores of Polyporus squamosus, Van Iterson (28), 
who developed methods for isolating cellulose-dissolving bac- 
teria and fungi, and Dox (19), who investigated the enzyme 
action of species of Penicillium and Aspergillus. It is interest- 
3 
