1906] HASSELBRING—APPRESSORIA OF ANTHRACNOSES 139 
on the surface appressed to the glass. By its vigorous growth it 
tilts the body to one side (fig. 2). 
The process of penetration was observed by sowing spores on 
berries of Berberis Thunbergii, which are readily infected by the 
fungus, although some other species seem to be 
immune. From the pore on the lower flattened side 
of the adhesion disc, a slender tube protrudes and 
dissolves an arrow channel in the wax covering the 
cuticle, Although at first very slender, the hypha 
soon becomes larger and dissolves large cavities in 
the wax (figs. 3, 4). The fact that these cavities 
are more extensive than is necessary for the accom- 
modation of the germ tube would seem to indicate 
that a solvent is secreted in sufficient quantities 
to accumulate on the outside of the infecting hypha. 
Finally the cell wall is perforated and the 
mycelium branches freely within the cells, at 
the same time sending hyphae into the neigh- 
boring cells. +The penetration of the germ tube 
through the cuticle of the apple has frequently 
been observed, although it has not been pos- 
sible to follow the mycelium farther, probably 
on account of the early collapse of the cells and the consequent 
Fic. 2.—Germi- 
nating appressoria. 
Fic. 3. Fic. a : 
Fics. 3, 4.—Infecting hyphae penetrating the cuticle 
of berries of Berberis Thunbergit. 
Mpa diet of débris. The channel in this case is very narrow 
ut well defined, Contrary to former supposition no previous Injury 
