226 
J. Ramsbottom, 
a very thick double membrane, a dense, vacuolate cytoplasm with coarse 
granular contents and fat bodies, and a rather large, centrally placed 
nucleus, which appears nipped in the centre in most cases as if it arose 
from the fusion of two nuclei. Sometimes the cyst contains two nuclei 
lying close together. Since the naked parasites are uninucleate, the 
author searched for fusing naked cells but did not find them. He 
records the fact that he has met with zoosporangia and resting sporangia 
in close proximity: they can even develop in the same cell. This he 
holds could not be brought about by different external conditions but 
could be explained by a fusion in the one case and its absence in the 
other. “Parasiten, die nicht Gelegenheit fanden zur Copulation, bilden 
Zoosporangien, jene, welche copuliert hatten, bilden Dauercysten/' The 
author holds that direct nuclear division may possibly take place in the 
resting spores similar to the amitosis in Synchytrium. 
Nèmec (1912) has also studied the development of Olpidium 
Brassicae. Faworsky (1910) had already worked at this fungus and 
Nèmec confirms, and adds to, his results. The youngest stages observed 
were naked spherical bodies with granular protoplasm. As growth 
proceeds the protoplasm becomes vacuolate and the nucleus shows a 
finely granular or fibrous structure and a large spindle-shaped nucleolus 
lying against the nuclear membrane. The nuclear contents next become 
thread-like and a paired arrangement of the threads is often seen. The 
parasite grows considerably before nuclear division occurs. The first and 
second divisions were not observed, though cases were seen suggesting 
that the nucleoli persist during the division. After further divisions (the 
number probably depending upon nourishment), the vacuoles disappear, 
the cytoplasm becomes finely granular, the nuclei reduced in size almost 
to a point, and the nuclear contents coarsely granular. The parasite now 
surrounds itself with a membrane and forms an exit tube. Nuclei enter 
this and probably divide once or twice. All nuclear figures found occur 
at the same stage; the spindle is very weakly developed and the chromo¬ 
somes could not be counted. During division the nucleolus disappears. 
The cytoplasm breaks up into uninucleate zoospores by the segmentation 
of the protoplasm from the exterior and by the formation of interior 
vacuoles. Most of the cysts observed were uninucleate but in a few 
cases multinucleate cysts were found which were obviously preparing for 
zoospore formation. 
Entophlyctis Brassicae and E. Salicorneae were also studied but 
chiefly from a morphological standpoint. The young stages of the former 
have a single nucleolated nucleus and dense cytoplasm which sometimes 
contains deeply staining masses. When the parasite reaches a certain 
definite size the nucleus begins to divide and zoospores are formed. The 
characteristic resting spores are also formed. These, at maturity, are 
uninucleate and have a dense cytoplasm containing deeply staining masses. 
The vegetative stage of E. Salicorniae is also uninucleate and later 
becomes transformed into a zoosporangium or a resting spore. 
Nèmec (1911) has investigated an organism which he names Sor- 
olpidium and places among the Myxochvtridiineae 1 ). The first stages 
seen were naked uninucleate cells with clear vacuolate cytoplasm. The 
1) For a criticism of this view see Bally, Mycol. Centralbl. 1913, 2, 292—293. 
