PLATE 3 
Sclerotiopsis concava (Desm.) Shear and Dodge 
A.—Mound-shaped mass of hyphae beneath the cuticle; radial growth not evident 
because this is a somewhat oblique section of the primordium. 
B —Section of a primordium at a slightly later stage, showing plainly hyphae 
spreading outward from a broad base. The short terminal cells by slight lateral ex¬ 
tension take part in the organization of the outer wall. 
C —Still older stage when the line of rupture is well marked. At the right can be 
seen a small region where the radially growing cell chains have not been ruptured. 
The break occurs first by the destruction of one or more of the cells of these radially 
oriented hyphae. The parallel arrangement of hyphal branches below the line of 
rupture is not the result of an upward growth after the rupture has occurred. 
X). —Section of a still older pycnidium, showing quite distinctly five of six swollen 
cells (center) and other masses of stainable degeneration products in the cavity at 
the right. . 
ESame section as the preceding except at a slightly deeper focus, showing better 
how the line of rupture cuts across the radially growing hyphae; degenerating cells 
at the right. 
F. —An older pycnidium, showing many swollen cells. . 
G. —A pycnidium found on leaf of dewberry; cavity partly filled with masses of 
detached hyphal cells which originally made up the bulk of the young pycnidial 
H. —More highly magnified picture of a portion of the section shown in F. The very 
small cells above the large ones are detached portions of the radially placed hyphae, 
portions of which may become the future sporophores. 
I. —Section of a small pycnidium still covered by the tightly stretched cuticle. 
The first permanent spores formed are still attached to sporophores. There is very 
little of stainable cell remains in the cavity. The radial arrangement of the cells 
which make up the wall of the pycnidium can still be plainly recognized. 
