186 



AMCEBA COLI. 



and, under favourable conditions of nutrition, rapidly repeated. 

 Under some circumstances an encystation takes place, when the 

 animal draws itself together into a sphere, and secretes a substance 

 originally mucous in nature. 



Amoeba coli, Losch. 



Lb'sch, "Massenhafte Entwickelung von Amoeben im Dickdarm," A rchiv f. pathol. 

 Anat., Bd. Ixv., p. 196, Taf. x., 1875. 



The body measures from 0*02 to 0*035 mm., is of a somewhat fluid 

 and coarsely granular nature, and forms usually only one or a few Uunt 

 and broad processes. These arise suddenly, and are not unfrequently 

 drawn in as suddenly, giving the otherwise roundish body a sometimes 

 oval, sometimes pear-shaped, or even irregular form. In the interior, 

 besides granules and food, a clear round nucleus may be recognised, 

 as also several vacuoles, sometimes irregular in shape and of varying size. 





FIG. 94. Amoeba coli in intestinal mucus, with blood corpuscles, Schizoniycetes, 

 and similar bodies (after Losch ). 



The A mceba thus shortly characterised (Fig. 94) has hitherto been 

 only once observed, namely in St. Petersburg, in a peasant who 

 suffered from an ulcerative inflammation of the large intestine. 1 It 



1 [Grassi states (Gazctta med. Ital Loinb., No. 45, 1879) that he has observed Amoeba 

 coli six times in Italy. The parasites were always present only in small numbers, and 

 in persons whose health had undergone no change. Cunningham also, who not unfre- 

 quently observed the occurrence of A moela in the human intestine, and still more often in 

 the cow and the horse, is disposed to attribute to it no special pathogenic significance. 

 The parasite occurs, however, in certain diseases of the intestine, especially in such as are 

 characterised by alkaline excreta and in cholera, and its presence may then be referred 

 to the specially favourable vital and developmental conditions found under such circum- 

 stances. Cunningham further holds that Flagellata parasitic in man are to be regarded 



