Davis . — The Fertilization of Batrachospermum . 61 
and behind the nucleus which indicated that the position 
of the cell-contents had been disturbed by the downward 
movement. The attention of the reader is called to the fact 
that the nuclei of the trichogynes in both cases occupy their 
usual positions in the middle portion of those structures, and 
that the two trichogynes are entirely separated from the 
carpogonia. In the specimen illustrated by Fig. n, the 
fertile filaments had begun to develop, showing that the car- 
pogonium had been fertilized. 
There appears to be no tendency on the part of the nuclei 
of the antherozoid and trichogyne to approach each other. 
It would be very unsafe to conclude that the examples in 
which they lay very close together had any great significance, 
because the position of the nucleus of the trichogyne is so 
very variable. 
In the majority of cases it is quite evident that the nuclei 
of the antherozoid and trichogyne remain entirely separate. 
It is true that one sometimes finds specimens, as Fig. 17, 
in which there is one large nucleus that might be considered 
as a fusion-nucleus ; but there have been other structures in 
such cells that have led the writer to believe that such was not 
the case, and these will be described later. 
The carpogonium, soon after its separation from the 
trichogyne, generally gives rise to several branches of 
three or four cells each, that grow downward and become 
pressed against the cell below. A great many short 
filaments arise from the cells of these primary branches, 
and they in turn fork and finally terminate in the spores. 
All the fertile filaments may be traced back to the 
carpogonium, although they frequently appear to come 
from the cell situated below that structure. It may be well 
to emphasize the fact that after the trichogyne is separated 
from the carpogonium, all communication between the two 
structures is for ever ended. The communication is never 
opened again, either by the absorption of the deposit between 
the two cells or by outgrowths from the trichogyne. The 
writer mentions this point to guard against any possible 
