Chapter 8 



THE 



TELOSPORASIdA 

 AND THE 



cocaviA 



PROPER 



All members of the class Telospo- 

 rasida are parasitic. They have simple 

 spores, without polar filaments. (The 

 spore has been lost secondarily in a few 

 genera. ) Each spore contains 1 to many 

 sporozoites. Pseudopods, cilia and fla- 

 gella are absent, except for flagellated 

 microgametes in some groups. Locomo- 

 tion is by body flexion or gliding. Repro- 

 duction is both sexual and asexual, and 

 there may or may not be alternation of 

 generations. Most Telosporasida are 

 saprozoic, but a few, including the tropho- 

 zoites of the malaria parasite, are holo- 

 zoic. 



Most of the Telosporasida probably 

 arose from the Mastigasida, but some may 

 have arisen from the Sarcodasida. How- 

 ever, it is difficult to be sure of their 

 origin because of their lack of the usual 

 organelles of locomotion. 



The classification of this and related 

 groups is still the subject of considerable 

 difference of opinion among taxonomists, 

 and that used in this book is not consid- 

 ered definitive. It may require several 

 generations of parasitologists to work out 

 a universally acceptable one. This class 

 is divided into 2 subclasses, of which the 

 Gregarinasina parasitize invertebrates 

 and the Coccidiasina occur in both verte- 

 brates and invertebrates. In the latter 

 group, the mature trophozoite is ordinar- 

 ily intracellular and comparatively small. 



The coccidia and their relatives belong 

 to the order Eucoccidiorida. In this order, 

 schizogony is present and the life cycle 

 involves both sexual and asexual phases. 

 Members of the order are found in the 

 epithelial and blood cells of vertebrates 

 and invertebrates. 



The coccidia proper belong to the sub- 

 order Eimeriorina, which is differentiated 

 from the other 2 suborders by several fea- 

 tures of its life cycle. The macrogamete 

 and microgametocyte develop independently, 

 the microgametocyte produces many micro- 

 gametes, the zygote is not motile, and the 



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