Dicranochaete reniformis Hieron. 115 
zoogonidium, many of which, in the quiescent state and lacking cilia 
but with the usual single red pigment-spot, were present in the same 
preparation. The fusion cells (zygospores) possessed a very delicate 
membrane and a vacuolate chlorophyllous contents; in some of 
them, two distinctly separate masses of chlorophyll were present, 
each mass containing one pigment-spot. Unfortunately, formalin 
had been run under the cover-glass to restrain the movements of 
certain active swarm-spores, so that the development of these fusion 
cells could not be followed, and I was never successful in observing 
them again. There seems no doubt, however, that the swarm-spores 
of Dicranochcete may occasionally function as gametes and fuse in 
pairs, the quadriciliate swarm-spores which were observed being 
possibly formed by fusion of two of the biciliate ones. 
No vegetative division appears to take place in this alga, but it 
was observed that young individuals which happen to be close 
together or in contact grow with the contiguous parts of their 
gelatinous sheaths flattened against each other and fused together 
(Fig. 1, L). Sometimes short filaments of 3 or 4 cells are 
produced in this way, presenting the false appearance of having 
been produced by vegetative division. Such cells are firmly united 
to each other and remain so when the filament is forcibly torn away 
from the substratum. 
According to Hieronymus many of the cells appear to pass 
through the winter in the vegetative condition. He also noticed 
certain cells which had formed a thick wall round themselves inside 
the usual membrane, constituting a sort of aplanospore, in which 
condition they probably perennate. 
The only other species of Dicranochcete recorded, as already 
stated, is D. britannica G. S. West, from N. Wales. This alga was 
free in a deposit obtained by squeezing submerged Sphagnum , but, 
according to West, there is every reason for supposing that when 
living it was epiphytic upon this moss. D. britannica differs from 
D. reniformis in its cells being more or less globose and in having 
a thick lamellose wall, with no indentation, the seta being dorsal or 
sub-dorsal. The method of reproduction of D. britannica is unknown 
but from the mode of occurrence of the alga it seems to be brought 
about by zoogonidia. 
Dicranochcete seems to occupy a somewhat isolated position 
in the Chlorophyceae, branched setae being present in no other 
genus of Green Alga, although small branches are sometimes given 
