HELICOSPORIDIA 



479 



Order 4 Helicosporidia Kudo 



This order has been created to inckide the interesting organism, 

 HeUcosporidium, observed by Keilin. Although quite pecuHar in 

 the structure of its spore, the organism seems to be best placed in 

 the Cnidosporidia, if it is a protozoan. 



Fig. 223. Diagram illustrating the probable development of Helico- 

 sporidia, X about 1600 (Keilin). a-c, schizont and schizogony; 

 d, sporont(?); e, three stages in formation of four-celled stage; f, hypo- 

 thetical stage; g, young spore before the spiral filament is formed; 

 h, mature spore; i, j, opening of spore and liberation of sporozoites. 

 a-h, in living host larva; i, j, in dead host body. 



The minute spore is composed of a thin membrane of one piece 

 and of three uninucleate sporoplasms, around which is coiled a 

 long thick filament. Young trophozoites are found in the host tis- 

 sues or body cavity. They undergo schizogony, at the end of 

 which uninucleate sporonts become differentiated. A sporont 



