In the Ascomycetes, certain cells or cell-processes associated with
the ascogonium have been described as trichogynes or receptive cells.
In one of the simpler types, Monascus[631], the “trichogyne” is a cell
cut off from the ascogonial cell. When fertilization takes place, the
wall between the two cells breaks down to allow the passage of the
male nucleus, but closes up when the process is effected. In _Pyronema
confluens_[632] it is represented by a process from the ascogonial cell
which fuses directly with the male cell. A more elaborate “trichogyne”
has been evolved in _Lachnea stercorea_[633], another Discomycete: in
that fungus it takes the form of a 3-5-septate hypha with a longer
terminal cell; it rises from some part of the ascogonial cell but has
no connection with any process of fertilization, so that the greater
elaboration of form is in this case concomitant with loss of function.
In the Laboulbeniaceae, a numerous and very peculiar series of
Ascomycetes that live on insects, there are, in nearly all of the
reproductive bodies, a carpogonial cell, a trichophoric cell and a
trichogyne. The last-named organ is in some genera a simple continuous
cell, in others it is septate and branched, occasionally it is
absent[634]. The male cells are spermatia of two kinds, exogenous or
endogenous, and the plants are monoecious or dioecious. Laboulbeniaceae
have no connection with lichens. Faull[635], a recent worker on the
group, states that though he observed spermatia attached to the
trichogynes, he was not able to demonstrate copulation (possibly owing to
over-staining), nor could he trace any migration of the nucleus through
the trichophoric cell down to the carpogonial cell. In two species of
_Laboulbenia_ that he examined there were no antheridia, and the egg-cell
acquired its second nucleus from the neighbouring trichophoric cell.
These conjugate nuclei divided simultaneously and the two daughter nuclei
passed on to the ascus and fused, as in other Ascomycetes, to form the
definitive nucleus.
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