PLATE 4 a 
Schizoparme straminea Shear 
A. —Section at an early stage in the growth of a pycnidium grown on agar; cells 
above the line of vertically oriented hyphae disorganized, thus determining the line 
of rupture; no buffer tissue yet formed. 
B. —A similar section at a slightly older stage; buffer tissue partly developed; 
location of the ostiole already determined by some disorganization of tissue; line of 
splitting below still being extended in both directions. 
C. —Section of pycnidium grown on agar under conditions which induce the inver¬ 
sion of the sporogenous tissue; buffer tissue erect and normal. 
D. —Section showing, like succeeding one, that the opening or rupture of the buffer 
tissue is caused by disorganization and not by a tearing apart due to inequalities in 
growth. 
E. —Disorganization of cells of the hood above and proliferation of cells bordering 
the cavity; buds growing into the space opened by disorganization. 
F. —Young pycnidial primordium on strawberry; large inner cells more or less 
oriented vertically. Above the center these cells are sending out short hyphal 
branches which are pushing into disorganizing cells in this region. 
G. —Similar to the preceding; protosporophores very distinct. 
H. —Section of two young pycnidia grown on strawberry. The buffer apparatus 
has broken through the host tissue above. 
I. —Section of a pycnidium similar to the preceding; gelatinizing ends of the in¬ 
cipient sporophores clearly visible. 
J. —Section of a pycnidium found on leaves of sumac; remains of disorganized cells 
lining the inner wall still attached. 
a Figures A, B, and H are from photographs by Marguerite Ickis. 
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