GREGARINA COCCIDIUM SCHUEERG* 10;, 



locomotor processes, " mouth," and contractile vacuoles, 

 as well as the thickness of the cuticle and the general 

 passivity, with the parasitic habit of the Gregarines. It is 

 not clearly understood how these and other intestinal 

 parasites have become habituated to resist the action of 

 digestive juices. 



Life history.- The young Gregarine is 

 parasitic in one of the lining cells of the 

 gut; it grows, and, leaving the cell, re- 

 mains for a time still attached to it by 

 the cap (Fig. 45, a, b, c) ; later this is cast 

 off, and the individual becomes free in the 

 gut, while still increasing in size. Two or 

 more individuals attach themselves together 

 end to end, but the meaning of this is 

 obscure. Encystation occurs, involving a 

 single unit or two together. The details 

 of spore-formation are similar to those in 

 Monocystis. All the protoplasm is not always 

 used up in forming the spores, but a residue 

 may remain, which forms a network of 

 threads supporting the spores. The cyst is 

 sometimes (as in G. blattarum) complex, 

 with "ducts" serving for the exit of the 

 spores, each of which is surrounded by a 6^-E 



firm case. Eventually the cyst bursts, the ^'-end "union 

 spore-cases are liberated, and from within of Gregarines. 

 each of these eight spores emerge to be- After Fren- 

 come cellular parasites. The adult of G. zel - 

 (Porospora) gigantea is sometimes three- 

 quarters of an inch in length enormous for a Protozoon. 



Ninth Type of Protozoa COCCIDIUM SCHUBERGI 



Coccidia are intracellular parasitic Sporozoa, attacking 

 mainly the epithelial cells of the gut or associated organs. 

 They are found chiefly in insects, myriopods, molluscs, and 

 vertebrates. 



Coccidium schubergi infests the intestinal epithelium of 

 the centipede Lithobius forficatus. The adult is a minute 



