1082 PARASITES OF PROTOZOA 



the body become much misshapen, the gregarine nucleus seemingly 

 degenerating. Stubblefield, however, found that more than six cysts 

 rarely occur in a gregarine. Caullery and Mesnil believed that heavily 

 parasitized gregarines are incapable of completing their sexual develop- 

 ment; and Ganapati and Aiyar remarked that parasitized gregarines 

 were not observed to associate. 



The affinities of the Metchnikovellidae are uncertain. They have been 

 related to fungi (Chatton, 1913, yeasts), to Microsporidia (Schere- 

 schewsky, 1924), and to Haplosporidia (Awerinzew, 1908). Caullery 

 and Mesnil (1919), while remarking on a certain similarity in nuclear 

 structure to Myxomycetes and Chytridiales, concluded that they are 

 isolated among the lower Protista. Doflein (Reichenow ed., 1927-29) 

 accepted their allocation to the Haplosporidia, and this position was sup- 

 ported by Stubblefield (MS) . 



Caullery and Mesnil (1919) provisionally designated as Bertramia 

 selenidkola a parasite of a species of Selenidhim from certain poly- 

 chaetes, and reported a related parasite in Selenidium virgula. Other 

 species of Bertramia are parasites in the body cavities of worms and 

 rotifers. Another parasite with apparent haplosporidian affinities, but 

 unlike Metchmkovella, was observed in a species of Polyrhabdhia. It 

 existed as isolated granules and multinucleate masses, the schizonts and 

 sporonts; and as separate ovoid bodies, not enclosed in a cyst, which 

 were evidently spores. 



Elmassian (1909) found a hyperparasite, Zooniyxa legeri, in Einieria 

 roux'i, which causes fatal coccidiosis in tench. He considered this to be 

 a haplosporidian, but also discussed its similarities to lower Mycetozoa. 

 It is likely that his account is at least in part incorrect. The parasite is 

 said to occur both on the surface of the epithelium and in the cells of 

 Elmeria, the intracoccidian parasitism being accidental. There are said 

 to be several types of schizogony, within coccidia or not; and in this 

 supposed haplosporidian the author described a sexual cycle with coc- 

 cidian-like development of microgametes and macrogametes, and the 

 formation of resistant cysts containing from six to twelve sporozoites. 

 The parasite has pathogenic effects on the nucleus and cytoplasm of 

 Eimeria, causing hypertrophy and eventual dissolution of the cell. 

 Elmassian thought that the effects are brought about by toxic secretions, 

 which act not only on the coccidia but also on the neighboring fish cells. 



