218 PARASITIC AMGEB.E OF MAN. 



fill research will result in proving that the parasite 

 also occurs in this country, for chronic forms of diar- 

 rhoea frequently occur in many portions of the United 

 States and monads are frequently reported as occur- 

 ring in the feces of such cases. It is very easy to 

 confuse the flagellate stage of Paramceba homims 

 with monads unless one is well acquainted with the 

 protozoa occurring in the intestine of man, and I 

 believe that it is not at all unlikely that many of the 

 cases of so-called monadic diarrhoea, or dysentery, are 

 in reality infections with Par amoeba hominis. It must 

 be admitted, however, that infection with this para- 

 site is rare as compared with the other species of 

 amoebse infesting man, or with infections with Tricho- 

 monas hominis, Lamblia intestinaUs, or even Balan- 

 tidium coli, for in my own experience, covering the 

 microscopical examination of several thousand speci- 

 mens of feces from as many individuals, both in health 

 and disease, I have found this organism in only nine 

 patients, three of whom were American soldiers, and 

 six native Filipinos. 



MORPHOLOGY AND LIFE-CYCLE. This parasite has 

 a complicated life-cycle, passing through both an 

 amoebic and a flagellate stage of existence. By making 

 repeated examinations of the feces of infected in- 

 dividuals I have been able to trace the entire life- 

 cycle and while I have been unable to reach definite 



