PROTOZOA 



Class SPOROZOA 



87 



Protozoa which in the principal phase have no external organs of 

 locomotion or are amoeboid ; are parasitic, and nearly always at some 

 stage intracellular; have no meganucleus; and form after syngamy 

 large numbers of spores, which may be sporozoites or undivided 

 zygotes. 



The two subclasses, Telosporidia and Neosporidia, of this class 

 have little in common, and their association in classification is a 

 matter of convenience. 



m-nu- 



nu 



Fig. 73. Various stages of Chondrioderma difforme. From Strasburger. 

 A, A spore hatching. B and C, Flagellulae. D, Young and E, Older amoe- 

 bulae. F, Amoebulae fusing to form plasmodium. All x 540. G, Portion of 

 Plasmodium, x 90. nu. nucleus. 



Though upon analysis the type of life history characteristic of the 

 Telosporidia is found to differ profoundly from those of the Neo- 

 sporidia, all sporozoan life histories are complicated. Usually they 

 comprise all the phases indicated in the scheme on p. 37, though in 

 the Eugregarinaria (and perhaps in the Actinomyxidea) agamogony is 

 omitted. Each phase, moreover, is liable to be elaborated. The term 

 sporoblast is applied to certain stages in various life histories, but un- 

 fortunately the stages so named are not all comparable with one 

 another. In the Telosporidia it denotes either the zygote or the 



