Fertilization of the Floridex. 7 
An open communication, so that an interchange of formed 
protoplasmic portions, cell-nuclei, or chromatophores could take 
place between the two neighbouring thallus-cells, is, how- 
ever, not established by these pits. Such an open communi- 
cation is indeed formed only in a few cases (Corallinee*) by 
the development of large open pores which are produced sub- 
sequently in the common dissepiment of neighbouring thallus- 
cells, analogous to the widely diffused H-shaped connexions 
of the hyphe of Ascomycetes and Basidiomycetes. 
II. 
On this thallus the sexual cells originate by the differenti- 
ation of certain terminal cells of the entire system of branched 
cell-filaments. 
The male cells are usually formed in great numbers toge- 
ther. Close to the generally small terminal cell of a shorter 
or longer branch-filament (one or) several small branch- cells 
are formed by the uppermost joint-cells, and these, like the 
terminal cell itself, become developed into male cells. The 
same thing is repeated in the second and often in the third 
joint-cell (sometimes also in the following joint-cells), or 
short, one- or more-celled lateral branchlets issue from these 
joint-cells, the terminal cells of which, as well as the 
branch-cells of the superior joint-cells, become converted 
into male cells. Hence the male cells are placed several 
together at the apex of the uppermost cell and at the upper 
endof the next following joint-cells of a simple or ramified 
branch-filament. Such branches are distributed sometimes 
singly, sometimes united in groups on the thallus of the 
different species of Floridez, and thus form so-called anthe- 
ridia of very multifariously variable structure. 
Such antheridia sometimes present the form of separate 
larger or smaller tufts of filaments (Callithamnion, Scinaia, 
&c.) ; but generally a greater or less number of such tufts 
closing plates of the pits as those organs of the individual cells which 
receive and use up the stimuli transmitted from neighbouring cells. And 
likewise, for various reasons, I would regard it as not impossible that the 
above-mentioned “mucilaginous masses” of the sieve-tubes (which, 
in my opinion, agree in substance with the closing plates) possess a func- 
tion perfectly analogous to that of these closing plates and their connecting 
cords, namely, essentially the using up and cones of CUA Me 
fluences, so that Hanstein’s idea (‘ Protoplasma,’ p. 172), that possibly 
the sieve-tubes of plants are comparable to the nerves of animals, would 
firmed. ce : 
ne . ie Bebra in ‘Sitzungsb. niederrh. Gesellsch, fiir Natur- und Heil- 
kunde,’ 1880, p. 122. 
