The Origin and Development of the Apothecium etc. 
409 
of grannles close the pores in the same way that the gelatinous material 
closes those in the carpogone of Collema. Cutting says that this terminal 
part of the archicarp of Ascophanus is usnally composed of three to five 
cells, but it sometimes seems to grow on. He does not call it a trichogyne, 
but from his description it seems not especially different from that organ 
in Lachnea stercorea and in Collema. It is possible that if it does not now 
function as a trichogyne it may have done so before the fungus became 
apogamous. Miss Ternetz (77) found that this terminal part of the 
archicarp may not only grow on, but that it may produce other ascogones 
which then become intercallary structures in this hypha. Neither Cut- 
ting nor Miss Ternetz found an antheridium. 
The changes in the thickness of the cross walls in the trichogyne 
of Collema pulposum and their affinity for the orange are very similar 
to phenomena described by Harper(52) for the antheridium of Phyllactinia. 
In this form, after the conjugation pore is closed, the wall of the antheri- 
dium increases in thickness by what seems to be mucilaginous degenera- 
tion. The swelling, too, is toward the interior of the cell. There is, ho- 
wever, a difference in that in Collema it is only the cross walls of the 
trichogyne which become gelatinized, the outer walls remaining un- 
changed. In Phyllactinia the thickening is less in the region of the closed 
conjugation pore and greatest on the wall of the antheridium opposite 
this pore. 
There is an important difference in nuclear behavior between the 
trichogynes of Pyronema and those of Collema pulposum. In Pyronema, 
the nuclei in the conjugation tube degenerate before the antheridial 
nuclei leave the antheridium. In Collema pulposum, the nucleus in the 
terminal cell of the trichogyne appears to degenerate early, but the nuclei 
in the other cells appear entirely normal when the cross walls are first 
perforated. I have traced only one carpogone in this stage. A later stage 
shows the nuclei of these lower trichogyne cells degenerated and the 
cross walls gelatinized. Since each cell contains a single degenerating 
nulceus, I have taken these for trichogyne nuclei and not for male nuclei. 
Baur (3) says that a nucleus is not to be found in the trichogyne cells 
after the walls are gelatinized; but it may be that he found only very 
late stages at which the disintegration of nucleus and cytoplasm had 
progressed much further than in the trichogyne which I have shown in 
Figure 38, PI. XXXIII. The deeplv staining content which he finds to 
be the remains of the disintegrating nucleus and cytoplasm, is probably 
the same that I find later (Figs. 27, 28, 29, PI. XXXII). 
I have found these old trichogyne cells narrower in the center because 
