168 BOTANICAL GAZETTE [FEBRUARY 
active for half a day or more, but seem to conjugate rarely except 
when confined in small amounts of fluid. 
The nature of the cyst (resting spore or zoosporangium) is 
determined on infection. 
The red pigment which is found at all “— of the life cycle is 
haematochrome or an allied lipochrome. 
Although the three races of Rhodochytrium appear to be geo- 
graphically isolated and affect different hosts, no morphological 
differences were detected between them. 
The germ tubes do not enter the stomata, but penetrate the 
epidermis at any point, usually in the vicinity of a vascular bundle. 
The cysts, both resting and temporary, are uninucleate until full 
size is attained. 
Their rhizoids extend along the vascular bundles, mostly in the 
phloem elements, which they destroy, but they also send haustoria 
to the vessels of the xylem. 
When mature the resting spores have a two-layered cellulose 
exospore and a thick non-cellulose endospore; most of the reserve 
food is in the form of starch; the nuclei are considerably shriveled 
by the withdrawal of karyolymph. 
The starch grains are similar to those commonly seen in the 
higher plants. 
No plastids could be found, the starch grains appearing to be 
built up directly in the plasma. 
The flaring necks of the zoosporangia are stopped by charac- 
teristic turbinate or bell-shaped plugs. 
During the last mitoses there is a contraction which results in 
a pseudo-segmentation, but true segmentation appears to be 
brought about by the precipitation of membranes around the 
preepere=: 
There is a deeply staining body at the base of the cilia of the 
zoospores which is connected with the nucleus. 
The primary nuclei, which reach the size of 50-60 #, have enor- 
mous nucleoli and peculiar amorphous masses of chromatin like 
Synchytrium decipiens. 
In the first type of mitosis, the spindle, which is usually unipolar 
at first, is formed from coarse acicular fibers that appear within 
