confluens and the Morphology of the Ascocarp. 371 
veloped above into paraphyses. I have pointed out above 
that Krabbe in his work on Cladonia may very likely have 
mistaken some form of storage hyphae, such as those I have 
described, for the ascogenous hyphae, and thus have been led to 
the false conclusion that ascogenous hyphae and paraphyses 
are ramifications of the same vegetative system. In stained 
microtome sections of Pyronema there is no necessity for such 
a mistake. The ascogenous hyphae develop much earlier 
than these swollen hyphae, and have largely disappeared 
in the lower part of the hypothecium when the latter appear. 
The nuclei also furnish an unfailing criterion, those of the 
ascogenous hyphae being two or three times the diameter 
of those in the vegetative hyphae. Furthermore, the asco¬ 
genous hyphae never appear as densely packed with proto¬ 
plasm as do these vegetative cells. 
The protoplasm of these swollen cells is finely differen¬ 
tiated in their central parts into a system of fibres which 
extend from one septum to the next (Fig. 24). These fibres 
are curved so that when taken together they form a strongly 
swollen barrel-shaped figure. This system of fibres is very 
prominent in the cells in question. Its interpretation is not 
easy. Perhaps the fibres represent paths along which materials 
are transported from one cell to the next. The piling up 
of protoplasm in these cells doubtless requires considerable 
transportation of foods from one cell to another, and this 
may possibly have led to the very conspicuous differentiation 
of these fibrous tracts. Whether there is actual protoplasmic 
continuity, or even protoplasmic contact, between these cells 
by means of pores their septa I have not determined. 
Ultimately these vesicular cells become emptied of their 
protoplasm and appear as other hyphal cells of the hypothe¬ 
cium except for their much larger size. 
General Conclusions. 
If we interpret the phenomena I have described as occurring 
in the antheridium and oogonium, in the light of what is 
CC2 
