COPROZOIC PROTOZOA IN THE FAECES 69 



jective, but the walls are colored and sculptured in various 

 ways. 



Sphaerita and Nticleophaga. These vegetable organisms 

 are occasionalK^ found parasitic in intestinal amoebae, 

 especiallv coelozoic forms such as Entamoeba coli, loda- 

 jjioelm biitschlii, and Endolimax nana. Sphaerita (Dan- 

 geard 1895) occurs in the host's cytoplasm as small spheri- 

 cal bodies which are made up of compactlv packed spores 

 (Figs. 2, 3 and 16, l). Because of high refractility, they are 

 very conspicuously noticed in living amoebae. The sphe- 

 roidal spores are 0.5-1 n in diameter. When stained with 

 Heidenhain's iron haematoxylin, thev are stained black, 

 but when differentiated, the spores appear to be made 

 up of a deeply staining cortical layer and a less deeply 

 staining core. The spherical group of spores is sometimes 

 about the size of the nucleus of the infected amoeba. 

 Nucleophaga (Dangeard, 1895) is a very closely related 

 form, but apparently develops in the nucleus of the host 

 amoeba (Fig, 16, -). The spores appear as dark-stained 

 granules and therefore have occasionallv been mistaken 

 for chromatin granules of the host nucleus. When heavilv 

 infected, the host nucleus becomes hvpertrophied and 

 completelv disintegrates. 



Blastocijstis Jwminis. This is an extremeh^ common 

 plant organism, considered to be a fungus, occurring in 

 human and various animal excrements. It is as a rule 

 spherical in shape (Fig. 16, '^-^) and is about 5-25m in 

 diameter, the commonest forms being about 8-12^. \\^ithin 

 a very thin membrane, there is a narrow peripheral c\ to- 

 plasmic layer in which 1-2 nuclei and several refractile 

 granules are present. This c\toplasmic ring encloses a 



