414 BOTANICAL GAZETTE [DECEMBER 
observed a nucleus in the trichogyne of Nemalion, which he assumes 
to be derived from the young carpogonium, although the mitotic 
figure was not found. The presence of a nucleus in the trichogyne 
necessitates a modification of our conception of the morphology of 
the female organ in the red algae. 
The earlier conception of the morphology of the trichogyne as 
given by Scumitz (69) was a cytoplasmic extension of the carpo- 
gonium, developed as the receptive organ for the sperm. This 
conception was followed by OxtMaNNs (55), SCHMIDLE (68), 
and OsterHout (57). Davis (17), however, concluded that the 
trichogyne is not a cytoplasmic extension from the carpogonium, but 
that it possesses a well-defined nucleus and hence has a certain degree 
of independence. The trichogyne of Batrachospermum has certainly 
a body that must be regarded as a chromatophore. Wo rer’s studies 
of Nemalion (86) support this view with respect to a trichogyne 
nucleus. In Polysiphonia, as stated above, there is present a tricho- 
gyne nucleus whose origin has been traced to a division in the terminal 
cell of the carpogonial branch. These facts have an important bear- 
ing on the structure of the trichogyne in lichens and Laboulbeniaceae. 
THAXTER (78) has described multicellular branching trichogynes 
in certain forms of Laboulbeniaceae, and the long multicellular 
trichogyne of Collema (BavEeR 6) and Physcia (DARBISHTRE 162) 
illustrate similar conditions. In the lower forms of algae where 
heterogamy is established, male and female gametes are generally 
formed in unicellular antheridia and oogonia. The female gametes 
having become non-motile, usually remain within the cogonium and 
are fertilized by motile male gametes which enter the oogonium 
through a pore, as is illustrated by Oedogonium. With the loss of 
motility on the part of the male gametes, a receptive region or structure 
seems to have been developed by the oogonium, and in this manner 
the trichogyne probably arose. However, the development of the 
trichogyne means that the female cell, which is the homologue of an 
oogonium, acts as a unit. Should there be in such a cell one or more 
mitoses, which are the remnants of ancient nuclear division when two 
or more gametes may have been developed, then the supernumerary 
nuclei would be expected to degenerate. This seems to be the con- 
dition in the red algae, where there is an extra nucleus beside the one 
