160 E. KUDO 



onts, respectively. The schizonts very frequently become 

 larger and elongated, assuming oblong shape with a large nucleus 

 (fig. 15). The protoplasm in such a form is more dense, although 

 it is equally finely reticulated as in rounded forms. The nucleus 

 undergoes division, while the body becomes more and more 

 elongated, often assuming a spindle shape (figs. 16 to 19). After 

 the completion of the division, the daughter nuclei, which seem 

 to be rich in nuclear fluid, move toward the opposite extremities 

 of the body. The constriction in the middle of the body becomes 

 deeper (figs. 20, 22), and finally the body separates into two. 

 The resulting forms are more or less elongated uninucleate spor- 

 onts (fig. 23). 



The schizogony observed in the present form, as is stated above, 

 is, on the whole, similar to that of Thelohania maenadis which 

 was described by Perez ('05). Although in many other species 

 repeated binary fission has been reported, without the complete 

 separation of the daughter cells, producing multinucleate sausage 

 or rosary forms, it was not observed in the present case. The 

 multinucleate forms have been recognized in the schizogony of 

 Thelohania mulleri (Stempell, '02), Thelohania chaetogastris 

 (Schroder, '09), and Thelohania varians (Debaisieux, '13). In 

 Thelohania corethrae, Schuberg and Rodriguez ('15) saw only a 

 schizogonic multiplication into eight daughter cells. 



As to the nuclear division during schizogony, amitosis seems to 

 have generally been observed in the majority of Microsporidia, 

 mitosis having only been reported in a few cases. Perez ('05) 

 observed that the chromatic substance of the nucleus of the 

 schizont of Thelohania maenadis became differentiated into eight 

 Y-shaped masses, and that after passing through a 'spireme' 

 stage, the chromosomes were divided into two groups, which 

 change he called a typical karyokinesis, Debaisieux ('13) appar- 

 ently observed a promitotic type of nuclear division in the schizo- 

 gony of Thelohania varians, which is highly different from any 

 ordinary amitosis, although he described it as amitotic division. 

 In other Microsporidia, investigators agree in reporting the nu- 

 clear change as a direct division, because of the minuteness of the 

 object. 



