VIII. B, 4 Walke7' and Sellards: Entamcehie Dysentery 297 



ENTAMCBBA HISTOLYTICA, STRAIN B 



This strain of Entamoeba histolytica was from a man suffering 

 from an acute attack of entamoebic dysentery, whose dysenteric 

 stools contained many motile entamcebee. The strain was used 

 in the following two experiments, and there were no subsequent 

 passages of it. 



Experiment LIII. — Man 5, aged 30 years, had been under observation 

 in the prison for seven years and six months. He gave a history of a 

 mucous dysentery of one month's duration seven years ago. He had been 

 used for a feeding experiment with a culture of Amoeba llG, two hundred 

 fifty-seven days previously (part 11, experiment XVII). The result of 

 this experiment was negative. At the time of the present experiment, 

 physical examination of his abdomen and cultural and microscopic exami- 

 nations of his stools for amoeboid organisms were negative. He ingested 

 motile Entamoeba histolytica, strain B. After the ingestion, cultures of 

 the stools of man 5 were negative for amoebae. Microscopic examinations 

 of his stools were negative for several weeks, and he was considered as a 

 nonparasitized control. However, on the forty-fourth day Entamoeba his- 

 tolytica was found in his stool and has persisted ever since. He has been 

 under observation one year since the beginning of the experiment. No 

 dysenteric symptoms have appeared. 



Experiment LIV. — Man 34, aged 30 years, had been under observation 

 in the prison six years. He had a negative dysenteric history, and 

 had not been used previously for experiments. Physical examination of 

 his abdomen and cultural and microscopic examinations of his stools for 

 amoeboid organisms were negative. He ingested motile Entaviozba histo- 

 lytica, strain B. Following the ingestion, cultures of the stools of man 34 

 were negative for amoebae. Entamoeba histolytica was found microscopically 

 in thfe stools of this man on the fourth day after the ingestion and has 

 persisted ever since. This man was under observation nine months after 

 the beginning of this experiment. No symptoms of dysentery developed. 



ENTAMCEBA HISTOLYTICA, STRAIN C 



Strain C of Entamoeba histolytica was obtained post mortem 

 from a fatal case of entamoebic liver abscess. The patient from 

 whom these entamoebse were obtained died at 11 o'clock in the 

 morning, a necropsy was performed at 1.30, and the entamoebae 

 were ingested by men 3 and 35 at 2.30 in the afternoon. There 

 were no subsequent passages of this strain. 



Experiment LV. — Man 3, aged 31 years, had been under observation in 

 the prison six years. He had a history of dysentery of one month's 

 duration sixteen years ago. He had been previously used for the following 

 experiments. Two hundred seventy-nine days previously he ingested a 

 culture of Amoeba lA. Result negative (part II, experiment I). Two 

 hundred sixty-seven days previously he had ingested a culture of Amoeba 

 lA. Result negative (part II, experiment III). Two hundred forty- 

 three days previously he had ingested a culture of Amosba lOG. Result 

 negative (part II, experiment XV) . Two hundred eight days previously 



