166 BOTANICAL GAZETTE [FEBRUARY 
would be pigmented with haematochrome. Should such a plant 
be discovered, the probabilities are that it would be placed in 
the Synchytriaceae rather than among the Phyllobiae, where by 
hypothesis it belongs. 
But it must be recognized that the comparison fails utterly at 
certain points. The germinating zoospore of Synchytrium does not 
form an external button on the surface of its host, and the zoo- 
spores are of different types, as shown above. These matters are 
regarded by some as fundamental criteria of relationship. PETER- 
SEN (23) considers that the presence of an external button in the 
Chytridiales is clear evidence that they have originated from the 
filamentous Phycomycetes. But this contention would lose its force 
if applied to Chlorochytrium and Rhodochytrium, for these would 
hardly be regarded by anyone as reduced Siphomycetes. The 
number of flagella borne by the zoospores is used as a fundamental 
~ basis of classification by Lotsy and by VuILLEMIN (32), who regard 
the genera with biflagellate zoospores as entirely distinct from the 
other Archimycetes, and classified with them merely because of 
accidental similarities in form, using as an example Myzocytium, 
which, however, appears distinct from the Chytridiales for other 
reasons as well. But the Javanese genus Woroninella was separated 
from Synchytrium almost entirely on account of the possession of 
biflagellate zoospores. In all other characters, including the large 
primary nucleus, it seems to be exceedingly close to Synchytrium. 
Our present information concerning Woroninella, which is al 
contained in a brief description without figures (RACIBORSKI 24), 
is too meager to enable us to judge whether it is transitional 
between Rhodochytrium and Synchytrium. But the description of 
Woroninella goes far to remove those objections to connecting the 
two that are based on the differences in the zoospores (see also 
footnote p. 163). 
As has been pointed out above in the detailed cytological com- 
parisons, there are some very striking resemblances in cytology 
between Rhodochytrium and Synchytrium. Some of these are 
peculiar to the two genera, being unknown in other organisms. 
The most conspicuous and perhaps the most significant of these is 
the enormously overgrown primary nucleus. It is evident that 
