iv PREFACE. 



During my service in the United States military 

 hospitals, notably the U. S. Army General Hospital, 

 Presidio of San Francisco, Cal., and the U. S. Army 

 Division Hospital, Manila, P. I., while a member of 

 the U. S. Army Board for the Study of Tropical 

 Diseases, material for the study of amoebic dysentery 

 was nearly always available, and could be utilized to 

 the best advantage. Because of most favorable op- 

 portunities I have for nearly twelve years devoted 

 much study to the amoebae occurring in this form of 

 dysentery and much of the data given in this mono- 

 graph is based upon the personal observations of 

 hundreds of cases of amoebic dysentery, both clinically 

 and upon the autopsy table, and upon the study of 

 thousands of preparations containing these organisms. 



Until the work of Schaudinn, published in 1903, 

 no clear distinction had been made between the 

 various species of amoebae infesting man, but he was 

 able to differentiate two species, one causing a form 

 of dysentery, to which he gave the name, Entamceba 

 Mstolytica; and another, a harmless commensal of 

 man, which he named Entamceba coll. I was able to 

 confirm his work while studying amoebae at the U. S. 

 Army General Hospital in San Francisco, and my 

 observations were published in 1905, being the first 

 published which confirmed Schaudinn' s work, so far 

 as I know. Regarding my studies upon Entamceba 

 Mstolytica, Hartmann, in the Archives fur Protis- 



