CHAPTER VI 



The Amoebae (Continued) 



Endamoeha gingivalis. History and Relation to Pyor- 

 rhoea Alveolaris. ^Morphology. Habitat and Effects. 

 Experimental Information. Prevention and Treatment. 



ENDAMOEBA GINGIVALIS 



The common amoeba of the human mouth is E^id- 

 amoeha gingivalis, discovered by Gros (1849) as the 

 first known parasitic amoeba of man. Since that 

 time is has been rediscovered several times ; by Stein- 

 berg (1862), by Grassi (1879), by Prowazek (1904), 

 and by others. It has naturally been given several 

 names by its discoverers, among which Amoeba 

 dentalis and Entamoeba buccalis are still used, al- 

 though erroneously, at times. 



At least as early as 1913 Professor Allen J. Smith of 

 the University of Pennsylvania w^as mterested in the 

 relation of this amoeba to pyorrhoea alveolaris and 

 was working on the problem. Associated with him 

 was Dr. M. T. Barrett, a dental practitioner. He 

 later had associated with him in the study of E. 

 gingivalis in the tonsils Dr. W. S. Middleton. In 

 1914 Barrett published a preliminary account of this 



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