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1896 | CERTAIN PYRENOMYCE10US FUNGI gil 
species had been in the laboratory but a few months and its 
spores germinated but developed no further. The others were 
older and refused even to germinate. 
Attention was now confined to the ascigerous colonies of the 
species in hand, and with methods previously described the fol- 
lowing observations were made. The mycelium is composed of 
septate threads, each cell of which contains several nuclei. With 
alum-eosin and carmalum stains, the nuclei are distinguishable 
merely as round points stained more deeply than the cytoplasm 
and lying at or near the center of a circular clear space. In the 
mycelium nothing more minute than this could be determined in 
regard to the structure of the nucleus. None of various stains 
tried succeeded in differentiating any elements. Any stain which 
affected the nucleus also attacked the protoplasm of the cell. 
The nuclear membrane was usually sharply defined as a dividing 
wall between the clear circle and surrounding cytoplasm. 
At various intervals in the mycelium certain cells were found 
which were more or less swollen (fig. 7). The protoplasm in 
these was more dense than in the adjoining cells as shown by 
the deeper staining. This over-staining made observations upon 
nuclei in these cells very uncertain, but the cells proved to be 
the beginnings of perithecia. The first dividing wall is thrown 
across parallel to the septa which delimit the original cell (fig. 
8). Each of the two daughter cells then divides by a wall per 
pendicular to this, forming a four-celled spherical body. As this 
Srows, further divisions occur somewhat irregularly (jigs. 9 t© 
77) until we have a body consisting of a solid mass of irregular 
cells as yet without any differentiation. Sometimes at this stage 
the young perithecium is surrounded by a single layer of mycel- 
lal threads which have arisen in the neighborhood of the origi- 
mab cell and interwoven themselves, forming a sort of wall for 
the perithecium. The wall proper in this species is not more 
than a Single layer of cells thick and in many cases it seems to 
be formed by the thickening of the cell walls of the outer layer 
of the spherical mass, without the assistance of any surrounding 
filaments. It does not become dark and hard until the perithe- 
