1912] GRIGGS—RHODOCHYTRIUM 167 
these are truly unicellular organisms devoid of nuclear as well as 
cell division until the beginning of the reproductive period. The 
single cell which composes the plant body does not show any notable 
specialization in its cell organs, but it reaches a size which is 
exceeded only by a very few of the largest infusorians, while no 
nuclei of anything like equivalent size are to be found elsewhere 
among the Protista. The resemblances in these primary nuclei 
are not merely superficial, but are emphasized by detailed com- 
parisons of their structure. Though their mitoses differ somewhat 
in detail, they also are certainly analogous in many respects. 
These cytological resemblances, coupled with the general simi- 
larity in gross morphology and the tendency toward parasitism 
so evidently manifest in the Phyllobiae, are certainly very sugges- 
tive. It is difficult to imagine that such peculiar cytological 
features originated independently. If the cytology of the other 
members of the Phyllobiae and of the genera closest to Synchytrium 
should fall into line with the evidence now available in Rhodochy- 
trium and Synchtrium, it would make a strong case in favor of a 
phyletic relationship between the two groups. But it would 
afford no reason for supposing them closely related, for Synchytrium 
appears to occupy an isolated position. The gap which separates 
it from Phyllobiae would appear to be of ordinal rank, and, at the 
same time, it is generally recognized that it is far from most other 
Archimycetes. Nor would it show that Synchytrium was derived 
directly from Rhodochytrium or even from Phyllobiae. But it 
would indicate that these forms may serve as a guide post pointing 
out the most probable location of the evolutionary path followed 
by the ancestors of Synchytrium. 
Summary 
Rhodochytrium does not appear in North Carolina until late in 
the spring; at first zoosporangia are most abundant, but late in 
the season only resting spores are found. 
The cysts are independent, not connected through their rhizoids. 
The zoospores are of the algal type and frequently contain starch 
grains, but are colorless except for the red anterior end; they are 
