Laboulbenia chaetophora and L . Gyrinidarum. 337 
their division is immediately followed by the separation of the superior 
supporting cell, which receives two of the four daughters, the other two 
remaining in what is now the ascogonium (Fig. 27). The two nuclei left 
in the ascogonium again divide, and a secondary inferior supporting cell is 
sometimes cut off which likewise appears to be characteristically binucleate 
(Fig. 28). The remnant of the ascogonium is still binucleate, and it may at 
once begin to bud off asci, or, as usually happens, first divide into two 
binucleate ascogenic cells (Fig. 28). 
So far no nuclear fusions, nor any indications of such, have been 
observed. 
By this time the perithecium has grown beyond the upper end of the 
receptacle, over which it curves as shown in Fig. 32. The supporting cells 
are still intact, but they are beginning to show signs of breaking down. 
This soon happens, and then the ascogenic cells with their asci come to lie 
free in the cavity of the perithecium, where they are sustained by the cells 
lining the perithecium. The latter are thin walled and well nourished. The 
upper cells lining the perithecium and the canal cells of the neck are 
crushed by the increasing mass of asci and spores soon after the perithecium 
has attained its maximum size, and eventually the same fate befalls those 
in the base of the venter* 
A general survey of the Laboulbeniales reveals the fact that the 
procarp is characterized throughout by the constant occurrence of two 
cells, the carpogonium and the trichophoric cell. There is always a tricho- 
gyne, but it is extremely variable. The trichophoric cell is of especial 
interest since it is not represented in the Florideae or the Uredineae, and, if 
represented, is not determinable in any other Ascomycetes. Whether it is 
to be looked upon as a part of the trichogyne or as a part of a two-celled 
* scolecite its history and functions call for closer scrutiny. In the apoga- 
mous species investigated in this paper its nucleus joins forces with that of 
the carpogonium, a phenomenon quite comparable, without any thought of 
implying homology, to the initial stages of fertilization in certain Uredineae 
and possibly in such sac-fungi as Ascobolus. 
Harper (’ 96 ) found that the cells of the scolecite of Ascobolus are 
primarily uninucleate, and that subsequently there is a migration of nuclei 
from cell to cell through perforations in the transverse septa of the scolecite. 
Welsford (’ 07 ) has fully corroborated his observations. Welsford states that 
‘the transverse walls of the scolecite are perforated medianly by large 
circular pores. Pores could not be identified in the earliest stages of 
development, and it seems possible that they may be of secondary forma- 
tion. The nuclei with the cytoplasm of the several cells pass through the 
pores till they reach the ascogenous cell, where they fuse in pairs.’ Though 
the history of individual migrating nuclei was not followed, the phenomena 
described are suggestive of what takes place in Laboulbenia chaetophora . 
