64 Davis . — The Fertilization of Batrachospermum . 
Batrachospermum coerulescens, SzA/A 
This plant, which agrees more closely with B. coerulescens , 
as Sirodot 1 has described it, than with any other species, was 
found in its best condition in the late fall, but it grows all 
through the winter and spring. The types of trichogyne and 
cystocarp are of such an opposite character from B. monili - 
forme that a careful comparison of the two species as regards 
the process of fertilization is very desirable. 
We shall take up the subject in much the same order as in 
B. moniliforme , so that the comparison maybe easily followed. 
The procarpic branch is very short, lying near the axis of 
the main branches, and bears a very narrow long trichogyne 
that arises from the terminal cell (the carpogonium). There 
are curious short filaments attached to the cells of the 
procarpic branch below the carpogonium, but they are of 
no great significance. 
The mature trichogyne contains a well-defined nucleus, as 
does also the carpogonium, but the most interesting feature 
about the contents of the trichogyne is the particularly 
prominent chromatophore-derivative. In very young tricho- 
gynes, when the process from the carpogonium is quite small 
(see Fig. 19), a homogeneous body of irregular outline may 
be clearly seen closely pressed against the cell-wall and 
extending usually to the very top of the cell. Its colour 
is distinctly green, and its outline may be followed without 
difficulty, as it runs into the carpogonium and there becomes 
the chromatophore of that structure. As the process, which 
represents the early stage of a trichogyne, gradually lengthens 
and swells into the shape more nearly like the mature 
structure, the chromatophore, which lay at first closely pressed 
against the cell-wall, is commonly left behind in the lower 
portion of the structure (see Fig. 20). The shape finally 
assumed by the chromatophore-derivative is very variable, 
and frequently lobes of the structure become detached (Figs. 
1 Sirodot, Les Batrachospermes, Paris, 1884. 
