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HANDBOOK OF PROTOZOOLOGY 



membrane, which is apparently of a single piece, envelops the 

 sporoplasm and the polar filament, a very long and fine filament. 

 The latter may directly be coiled in the spore or may be encased 

 within a polar capsule which is similar to that of a myxospori- 

 dian or actinomyxidian spore in structure, but which is mostly 

 obscure in vivo, because of the minuteness of the object. 



When such spores are taken into the digestive tract of a 

 specific host (Fig. 136), the polar filaments are extruded and 

 perhaps anchor the spores to the gut-epithelium. The sporo- 



Fig. 136 Diagram showing the probable development of Stempellia magna. 



X800 (After Kudo), 

 a, b, germination of spore in the mid-gut of culicine larva; c-k, stages in 

 schizogony; I-p, sporont formation; q-t, formation of one, two, four and eight 

 sporoblasts; u, a sporoblast; v-x, transformation of a sporoblast into a spore. 



plasms emerge through the opening after the filaments become 

 completely detached. By amoeboid movements they penetrate 

 through the intestinal epithelium'and enter the blood stream 

 or body cavity and reach their specific site of infection. They 

 then enter the host cells and undergo schizogonic multiplication 

 at the expense of the latter. The schizonts become sporonts. 



