PARASITES OF PROTOZOA 1047 



termes hispaniolae, and reported it also in E. majestas, E. simulans, and 

 Endolimax termhis; and Sassuchin ( 1931 ) found a chytrid in the nucleus 

 of Entamoeba citelli. In Entamoeba ranarum, Lavier (1935a, 1935b) 

 found a parasite described as Nudeophaga ranarum. Although not a 

 protozoan parasite, and one that is of doubtful affinities, the organism 

 named Erythrocytonucleophaga ranae by Ivanic (1934), which invades 

 the nuclei of the red blood cells of Rana esculenta, is interesting to con- 

 sider in this connection. 



LIFE HISTORY AND STRUCTURE 



Sphaerita. — Chytrids of the family Olpidiaceae, to which SphaerHa 

 and Nudeophaga belong, have a one-celled, intramatrical thallus, 

 enclosed from an early period by a delicate membrane, amoeboid in 

 nature, which at maturity changes into a single sporangium or resting 

 sporangium. The sporangium of Sphaerita lacks elongate discharge tubes, 

 the spores escaping through an opening or papilla at one or both ends. 

 The zoospores of chytrids of this family are uniflagellate, according to 

 Minden (1915), Fitzpatrick (1930), and Gwynne-Vaughan and Barnes 

 ( 1937) ; but in the spores of many forms in Protozoa, either two flagella 

 or no flagella have been observed. 



Sphaerita has often been encountered in only a small percentage of 

 the host species, but some records report a high incidence. NoUer ( 1921 ) 

 found, in certain material, the majority of Endolimax nana and a very 

 high percentage of Entamoeba coli infected; and Dobell (1919) saw 

 several E. nana infections in which a considerable proportion of the 

 amoebae were parasitized. Sphaerita was present in 80 percent of E. coli 

 and E. histolytica studied by Lwoff (1925). Both Becker (1926) and 

 Sassuchin et al. (1930) found E. citelli in certain ground squirrels very 

 heavily parasitized, and Yuan-Po (1928) reported about 60 percent 

 infection of Entamoeba bobaci. Almost all Chilomastix in a guinea pig 

 contained 5". chilomasticis (Cunha and Muniz, 1934). In flagellates of 

 termites, infection varies from light to heavy. In a few instances almost 

 every individual of certain devescovinids on some slides has been para- 

 sitized; on the other hand, the parasite may be infrequent or absent 

 in other host faunules of the same species. Distributional factors would 

 facilitate the presence of the chytrids in higher incidence in endozoic 

 than in free-living Protozoa under natural conditions, but an infection 



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