WINGE, CYTOLOG. STUDIES IX THE PLASMODIOPHORACE.^. 21 



sporogonic stage. It commences in this way that the resting 

 globular schizont-nucleus becomes very slightly spindleformed 

 and exhibits radiation-phenomena from the poles (fig. 31) 

 where possibly two centrosomes are situated. At the same 

 time the caryosome enters into plainer connection with the 

 periphery of the nucleus, as the hitherto thin chromatin- 

 filaments which have radiated from the caryosome become 

 more solid, the nuclear membrane disappears and the chro- 

 matin travels along the filaments, preferably towards the 

 poles where two chromatic bodies are often formed (fig. 32 — 35). 

 Another modification which has frequently been observed 

 has been mentioned previously in Plasmodiophora by Pro- 

 \VAZEK (1. c), namely a stage at which the chromatin is seen, 

 arranged in garlands which, at any rate in Sorodiscus, are 

 most often attached to both poles (fig. 36, 37). 



We now enter into the final sporogonic phase which is 

 characterized by two succeeding divisions, a mitosis and a 

 meiosis. The caryosome is now perfectly resolved, only the 

 chromatin-filaments are left and they arrange themselves so 

 that they chiefly travel from pole to pole and deposit the 

 chromatin in equator (fig. 38, 39) where a plate is thus formed, 

 namely the metakinetic chromatin plate essential to the next 

 nuclear division. Meantime the nucleus changes form and 

 becomes spindleformed, and the plasma of the amoeba (the 

 schizont converted into a sporont) commences slowly to sepa- 

 rate into small uninucleate spore-mother cells which simulta- 

 neously pass through the following caryokinetic phases (fig. 40). 

 The polar radiation is still going on, but is now above maxi- 

 mum. The nuclear spindle, formed by the hyaloplasmatic 

 strings, is intranuclear (fig. 40, 43). The chromatin arranges 

 itself in 16 chromosomes (fig. 41), presumably arisen by the 

 splitting up of 8 chromosomes, for most often two and two lie 

 nearer each other, and 8 chromosomes travel to both poles. 

 The two sets of chromosomes, however, for a time keep up 

 the connection with each other by the aid of chromatic and 

 hyaloplasmatic strings (fig. 44, 45, 42). The daughter-nuclei 

 separate from each other as represented in fig. 42 and 46. 

 When the nuclei part, slight polar radiations are still seen. 

 Immediately afterwards the binucleate amoebae divide, so 

 that they again become uninucleate, but they do not grow 

 so much that they attain the size of the former ones. Then 



