MORPHOLOGY AND TAXONOMY OF THE SPOROZOA 553 



tissue cells destroyed. In many species tumor-like masses are 

 formed in which the organisms are surrounded by a membrane 

 derived from the host and are thus encapsulated; in other species 

 such membranes are absent. In the majority of cases spread of 

 the infection in the same host comes to an end with sporulation, 



Fig. 222. — Stempellia magna, life cycle. A, Developmental stages of young 

 amebula from spore S; B, stage of nuclear increase; C, formation of sporont; D, 

 formation of a single spore; E, formation of two spores; F, formation of four spores; 

 O, of eight spores; H, development of uninucleated spore with polar capsule. (After 

 Kudo.) 



but in some species renewed infection is brought about by the 

 action of the digestive fluids on spores formed in the same organism 

 (Kudo). 



Multiple endogenous budding, or fragmentation of the tropho- 

 zoite into numerous binucleate agametes, is described for some 

 forms (Debaisieux, 1920) and these, as in Telosporidia, ultimately 



