INTRODUCTION In 1914 the writers published the results of their experience for six years in Ancon Hospital, with respect to the diagnosis, symptomatology and treatment of amebic dysentery. As will be shown later, exceptional and ample facilities were afforded for the study of all phases of human infection with the entamebas of the intestinal tract. Deeks correlated the data on the clinical aspects and the treatment, while James made a study of the entamebas themselves, with respect to the association of their various types with the symptomatology of the infections. At this time Deeks demonstrated at least 14 different etiological factors in the Canal Zone, responsible for the symptoms of dysentery. Many of these factors, it is true, were infrequently concerned in our Clinics, but none the less had to be taken into consideration in establishing a diagnosis.