Davis — The Fertilization of Batrachospennnm. 67 
nucleus of the trichogyne are shown near together in Fig. 28, 
while a similar condition in the antherozoid is indicated in 
Fig. 30; and in the specimen from which Fig. 31 was drawn, 
fragmentation had taken place in both structures at the same 
time. The nuclear fragments may finally be quite widely 
scattered in the cytoplasm (Fig. 29 and 32, t\ and the process 
of division is sometimes carried on until several derivatives of 
the primary nucleus exist in the cell. 
The essentials of the structure and development of the 
cystocarp are precisely the same as in B. moniliforme , although 
there are minor differences in the length and arrangement of 
the fertile filaments. The appearance of a crushed-out de- 
veloping cystocarp is shown in Fig. 32, where t — trichogyne, 
c — carpogonium, and s = sterile filaments from the cell below 
the carpogonium. 
Batrachospermuni coendescens therefore agrees with B. mo- 
niliforme in all the important characteristics of the phenomenon 
of fertilization. Certain structures of the trichogyne and 
antherozoids are illustrated much better, as for example the 
presence of the chromatophore-derivative in the trichogyne 
before and after the fertilization of the carpogonium ; in fact, 
it was here that the attention of the writer was first called to 
this curious cytological condition. 
Batrachospermum Boryanum, Sirdt. 
The trichogyne of B. Boryanum is very variable in size 
and shape, ranging from an almost globular structure to 
a lengthened form in which the end is sometimes very much 
prolonged. The general type of procarp is, however, some- 
what similar to B. moniliforme. The cells are smaller than 
in the two species previously described, and consequently it 
is a less satisfactory form to study ; but the writer made as 
careful an examination of the cytological conditions here 
as in the other species. 
There is a nucleus in the trichogyne as well as in the 
carpogonium ; and in the former there is also a more or 
F 2 
