284 The Philippine Journal of Science mz 



in the prison five years and five months. He had not been used previously 

 for experiments. He had a negative dysenteric history. Physical examina- 

 tion of his abdomen was not made. Cultural and microscopic examinations 

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

 Entamceba coli, strain E, mixed with powdered starch. This man was 

 under observation eight months after this experiment began. Cultures 

 of his stools for amoebae have been constantly negative. Microscopic 

 examinations showed Entamoeba coli in his stools on the second day and 

 more or less constantly thereafter. No symptoms of dysentery have 

 developed. 



Experitnent XXXVI. — Man 24, aged 25 years, had been under observa- 

 tion in the prison three years and nine months. He had not been used 

 previously for experiments. He had a negative dysenteric history. No 

 physical examination was made of his abdomen. Cultural and microscopic 

 examinations of his stools for amoeboid organisms were negative. He 

 ingested cysts of Entamceba coli, strain E, mixed with powdered starch. 

 This man has been under observation eight months since this experiment 

 began. Cultures of his stools for amcebse have been constantly negative. 

 Microscopic examinations showed Entatnoeba coli in his stools on the 

 seventh day and more or less constantly thereafter. No symptoms of 

 dysentery have developed. 



Experiment XXXVII. — Man 25, aged 26 years, had been under observa- 

 tion in the prison four years and one month. He had not been used 

 previously for experiments. His history with reference to dysentery was 

 negative. No physical examination was made of his abdomen. Cultural 

 and microscopic examinations of his stools for amoeboid organisms were 

 negative. He ingested cysts of Entamceba coli, strain E, mixed with pow- 

 dered starch. This man was under observation eight months after 

 this experiment began. Cultures of his stools for amcebae have been con- 

 stantly negative. Microscopic examinations showed Entamceba coli in his 

 stools on the second day and more or less constantly thereafter. No 

 symptoms of dysentery have developed. 



Experiment XXXVIII. — Man 26, aged 19 years, had been under observa- 

 tion in the prison two years and eleven months. He had not been used 

 previously for experiments. He had a negative dysenteric history. No 

 physical examination was made of his abdomen. Cultural and microscopic 

 examinations of his stools for amoeboid organisms were negative. He 

 ingested cysts of Entamceba coli, strain E, mixed with powdered starch. 

 This man has been under observation eight months since this experiment 

 began. Cultures of his stools for amoebae have been constantly negative. 

 Microscopic examinations of his stools were also negative; that is, this 

 man failed to become parasitized with Entamceba coli. No symptoms of 

 dysentery have developed. 



Experiment XXXIX. — Man 27, aged 40 years, has been under observa- 

 tion in the prison seven years and one month. He had not been used 

 previously for experiments. He had a negative dysenteric history. No 

 physical examination was made of his abdomen. Cultural and microscopic 

 examinations of his stools for amoeboid organisms were negative. He 

 ingested cysts of Entamceba coli, strain E, mixed with powdered starch. 

 This man has been under observation eight months since this experiment 

 began. Cultures of his stools for amoebae were constantly negative. Mi- 

 croscopic examination showed Entamceba coli in his stools on the second 



