conjluens and the Morphology of the Ascocarp . 355 
of the ascus-fruit until the entire sexual apparatus collapses 
at a late stage in development. The fusion of the conjugating 
tube with the oogonium is thus relatively transitory when 
compared to its fusion with the antheridium, and herein 
doubtless is the reason why Tulasne and Kihlmann failed 
to discover the former fusion while perfectly familiar with 
the latter. The reason for rebuilding the wall in one case 
and not in the other is perfectly apparent in that the oogonium 
is to develop further, while the functional activity of the 
antheridium and conjugating tube is completed with the ac¬ 
complishment of fertilization. 
The male nuclei, as has been noted, on entering the 
oogonium mingle with the egg-nuclei in the more or less 
central group into which the latter have collected. The 
nuclei are indistinguishable in size, structure, and staining 
qualities, so that it is quite impossible to pick out a single 
nucleus at this stage and say with certainty whether it has 
come from the oogonium or antheridium originally. We 
have simply a mass of scores of nuclei which have been 
brought together in the manner just described. These nuclei 
fuse in pairs, while they are yet aggregated in the dense mass 
described above. Fig. 15 shows a section of this mass at 
a stage when many of the fusions are complete. Fig. 15 a 
shows a section from another oogonium in which most of the 
pairs have fused. The mass is so dense at this stage as to 
make the study of the individual nuclei in its centre quite 
difficult even in very thin sections, but at the margin of the 
mass, and in tangential sections from its surface numerous 
pairs of nuclei can be found in various stages of fusion. Parts 
of such tangential sections showing fusing nuclei in various 
stages and from different oogonia are shown in Figs. 1 6, 1 6 a, 
and 1 6 b. Fig. 16 is from an oogonium with a crescent¬ 
shaped mass of nuclei. The other two are from oogonia 
with spherical masses of the type shown in Figs. 15 and 15#. 
Although the nuclei from the antheridium are not distin¬ 
guishable in size or appearance from those already in the 
oogonium, still there seems no reason to doubt that such 
B b 2 
