520 PROTOZOA 



occurring in human beings has been found in about 60 cases, principally 

 in Sweden, but also in Russia, Scandinavia, Finland, China, Italy, Ger- 

 many, and the United States. Most of these cases were suffering from 

 severe chronic intestinal catarrh, often accompanied by bloody diar- 

 rhrea. A number of observers think the balantidium the primary 

 cause of the catarrh, others think it a secondary excitant, while still 

 others believe it to be a harmless inhabitant of the intestines. 



Schaudinn has described two additional species of balantidium found 

 in the human intestines, which he has called Balantidium minutum and 

 Nyctootherus faba, probably both non-pathogenic. 



