6q Davis . — The Fertilization of Batrachospermum . 
acid or with chlor-iodide of zinc ; but these reagents do not 
give very satisfactory results with the walls of the vegetative 
cells. However, the general resemblance in appearance and 
behaviour towards certain stains has led the writer to conclude 
that, if not cellulose, it is at least closely related to that 
substance. 
If it is cytoplasmic communication between the antherozoid 
and trichogyne which causes the separation of the latter from 
the carpogonium, it is interesting to note how large must be 
the point of fusion. In some cases, as for instance the 
example shown in Fig. 8, the points where the protoplasm 
of the antherozoids were pressed against the protoplasm 
of the trichogynes were so small that open communication 
could not be seen. While the points of fusion in the great 
majority of specimens were very much larger than in this 
case, still they are often very small, much smaller than the 
nuclei of the antherozoids. Fig. 9, which illustrates this 
point, is also interesting, because it shows the peculiar 
manner in which the antherozoids tend to lengthen in the 
direction of the trichogynes. In Fig. 10 the nuclei of the 
antherozoid and trichogyne both lie very close to the point 
of fusion. The connecting strand of protoplasm between the 
two structures was much smaller than the nuclei, and the 
trichogyne was separated from the carpogonium. The example 
is unusual, the only one observed, and the writer would not 
like to attach any particular significance to the peculiar situa- 
tions of the two nuclei. 
We will now consider certain gradual changes which may 
take place in the position of the nucleus of the antherozoid. 
It is true that the nucleus of the antherozoid is often found 
in or near the upper portion of the trichogyne, and such cases 
are always those in which the fusion-strand is very broad. 
Fig. 11 illustrates this point, the nucleus lying directly in the 
opening between the antherozoid and trichogyne. In the 
example shown in Fig. 12 , the nucleus of the antherozoid 
had passed into the upper portion of the trichogyne, and 
there was a peculiar arrangement of the cytoplasm before 
