Smithsonian Report, 1939.— Meier 



Plate 1 l 



/. 



Z^'^^^.^-.^^m 



y 













Courtesy of U. S. Public Health Service. 



Protozoans. 



], Three stages of a nonpathogenic endanaoeba of man; 2, four stages of spore formation of a nonpathogenic 

 endamoeba of man; 3, stages of Entamoeba dysenteriae, the parasite of amoebic dysentery of man. Greatly 

 magnified. 



