270 The Philippine Journal of Science wis 



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

 the prison for six years and two months. He gave a history of dysentery 

 of one month's duration sixteen years ago. He had been used for 3 previous 

 feeding experiments (experiments I, III, and XV) the last of which was 

 thirty-four days previously, and all of which were followed by negative 

 results. Physical examination of his abdomen and microscopic and cul- 

 tural examinations of his stools for amoeboid organisms were negative. 

 He ingested the growth on 4 agar-slant cultures of Amoeha 5D, isolated 

 in culture from hay, mixed with magnesium oxide. The cultures ingested 

 by this man contained motile forms of the amoeba exclusively. Amceba D 

 was recovered in cultures from the stools of this man on the second and 

 third days after feeding, but never subsequently. Microscopic examina- 

 tions of his stools for amoeboid organisms have been constantly negative. 

 This man has been under observation two years and four and one-half 

 months since the experiment began. No symptoms of dysentery have 

 developed. 



Experiment X. — Man 9, aged 27 years, has been under observation 

 in the prison for five years and three months. He had a negative dysenteric 

 history, and had not been used for previous feeding experiments. Physical 

 examination of his abdomen was negative. Microscopic examination of 

 his stools showed a few Entamoeba coli. Cultural examinations of his 

 stools for amoebae were negative. He ingested the growth on 2 agar-slant 

 cultures of Amceba 6E, mixed with magnesium oxide. Amceba E had been 

 isolated in culture from fresh-water algse obtained from Kansas, United 

 States. The cultures fed to this man contained encysted amoebae only. 

 Transplant cultures made to test the viability of the cysts showed a good 

 growth of Amceba E. Following the feeding, cultures of this man's stools 

 showed Am.ceba E on the first and second days after feeding, but never 

 subsequently. Microscopic examinations of his stools have constantly 

 showed a few Entamasba coli. This man was under observation three 

 months. No symptoms of dysentery developed. 



Experiment X demonstrates the morphological and biological 

 differences between the cultivable amoebag and the parasitic 

 entamoebas. Amoeba E was recovered in culture, but could 

 not be found microscopically in the stools of this man; on the 

 other hand, Entamceha coli was identified microscopically, both 

 before and after feeding Amoeba E, but could not be cultivated. 



Experim,ent XI. — Man 7, aged 30 years, had been under observation in 

 the prison for four years and eight months. He gave a history of 3 attacks 

 of dysentery, each of one week's duration, six years ago. He had not been 

 used for previous feeding experiments. Physical examination of his ab- 

 domen and microscopical and cultural examinations of his stools for 

 amoeboid organisms were negative. He ingested the grovrth on 4 Petri- 

 plate cultures of Amoeba 8A, mixed with magnesium oxide. This strain 

 of Amoeba A, which is the same species as the amoeba common in the 

 Manila water supply, had been isolated in culture from a stool of a healthy 

 man. The cultures fed in this experiment contained only encysted amcebae. 

 Transplant cultures to test the viability of these cysts showed a luxuriant 

 growth of Amoeha A. Following the feeding, cultures and microscopic 

 examinations of the stools of this man for amoeboid organisms have been 



