120 R. KUDO. 



From the 1919 material I described both binary fission and 

 multiple division of the schizonts which produced uninucleated 

 forms; but a study of the preparation stained with Heidenhain's 

 stain and also of the large number of 1920 preparations, leads me 

 to think that the resulting form of the schizogonic divisions is a 

 binucleate form such as are shown in Fig. 2, o. 



As the two nuclei of the schizont come in a close contact, each 

 karyosome buds off small chromatin granule which seems to be 

 extruded into the cytoplasm later (Fig. 3, a). The nuclear 

 membranes between the two nuclei disappear, while the two 

 karyosomes become fused into one. The chromatin grains that 

 were thrown out into the cytoplasm seem to divide further (Fig. 



3,*). 



This uninucleate body is the sporont and gives rise to spores 



through sporogonic development described below. The fusion of 

 two "cousin" nuclei observed in Thelohania legeri (Kudo, '24) 

 does not exist in the present species. Debaisieux ('19) describes 

 a similar change in the schizonts of Thelohania varians. Other 

 references on this point are omitted here, since it was brought up in 

 detail in one of my recent papers (Kudo, '24). 



SPOROGONY. 



After growing somewhat in size the uninucleate sporont 

 divides. Its karyosome divides into two which become separated 

 by a nuclear wall and the two nuclei are formed (Fig. 3, c, d). 

 The nuclei become separated from each other and locate them- 

 selves near the opposite extremities. A septum appears in the 

 cytoplasm, and two sporoblasts are formed (Fig. 3, d}. Each 

 sporoblast develops into a spore. 



Frequently the two daughter nuclei divide once more. The 

 division begins with that of the karyosome, a strand remaining 

 usually between the divided karyosomes. Thus a tetranucleated 

 sporont is formed ; the cytoplasm, as in the case of bisporoblastic 

 sporont, divides into four sporoblasts (Fig. 3, /), each of which 

 develops into a spore. 



Less frequently a sporont nucleus divides three times, thus 

 producing eight sporoblasts (Fig. 3, g) which later develop into 

 eight spores. 



