WINGE, CYTOLOG. STUDIES IN THE PLASMODIOPHORACE.E. 3 



as they have nuclei, and every portion by and by is rounding 

 off representing a young spore. 



Nawaschin's only essential mistake, as it has later on 

 been pointed out by Prowazek (1. c.) is that in reality two 

 mitotical divisions take place instead of a single one. After 

 the description of Prowazek, however, also a caryogamy is 

 found in the myxamoebae before the completed formation of 

 spores — as is the case with the myxomycetes — and further 

 he is of opinion that one of the two fusing-nuclei even before 

 this final fusion in the young spore undertakes a division 

 connected with chromosome-reduction, while the other one 

 persists undivided. His figures of these phenomena carry but 

 little conviction. In connection with this presumed fusion 

 lie explains also two types of nuclei in the late vegetative 

 (amoeba-)phase of PlasinodiopJiora, the first t\^pe having the 

 chromatin split into small bits, which are conglomerated in 

 eight chromatin bodies, the other retaining for a while a 

 nucleolus and having the chromatin distributed into strin^^s 

 and garlands, which by and by are moved out to the peri- 

 phery of the nucleus, whereupon the nucleolus disappears. 

 The number of chains he states to be eight, at least some 

 times. Prowazek explains that »Die beiden Typen von 

 Kernvereänderungen dürften auf geschlechtliche Differenzie- 

 rungen zurückzuführen sein >. — We may add, that these types 

 — especially the garland-type — may also often be seen in 

 other Plasmodiophoraceae, they being but two of manyfold 

 variations of distribution of the chromatin at this stage. 



Another observation of Prowazek that a subsequent 

 radiation of chromatin into the protoplasma thereupon takes 

 place, an observation, which he compares with the conditions 

 as they are described for the Mycoplasma-nuclei (Eriksson 

 a. o.) and according to which the nuclei are finally entirely 

 resolved, whereupon new »Geschlechtskerne» are formed, is 

 judging from my own observations on other Plasmodiophora- 

 ceae not correct. It is true that the chromatin grew less 

 conspicuous and a partial radiation to the plasma cannot be 

 absolutely denied, but the vegetative nuclei never disappear 

 entirely; at all events the cavity of the nucleus can always 

 be discerned (hereon later). 



In 1909 the above named treatise by Maire and Tisox 

 was published, in which they shortly treat the cytology of 



