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In the intestine such a bacterial svmbiosis is still more definite and 
select. This specificity of the bacterial symbiosis increases with the 
parasitism of the amceba until, sometimes in the bowel and usually in 
liver and other abscesses, the bacterial symbiosis is eliminated and the 
amoeba assumes the réle of a strict parasite living directly at the expense 
of the host. 
We have been again unable to find amcebe as prevalent in the stools of 
human beings in Manila as have been reported for this locality and for 
‘other countries during the last few years. 
The presence of amoebe in a healthy bowel is not a convincing argu- 
ment against the pathogenicity of these parasites, but so far as the Philip- 
pine Islands are concerned, the continued propagation of amcebe of any 
kind in a healthy bowel is surely an infrequent occurrence. The difficulty 
of recognizing a “healthy intestine” has been pointed out, and we have 
discussed some of the conditions which may lead to error in diagnosis. 
We must question the justification for establishing a pathogenic and a 
non-pathogenic species of amoebee from the data given for the differentia- 
tion between “HF. colt” and “FE. histolytica.” The reasons for this have 
been fully set forth in the article, some of the important points being as 
follows: Amoebe found in the stools of so-called healthy people do not 
always conform to the descriptions given for “FH. coli.” Amoebe found 
in scrapings or sections from dysenteric lesions of the bowel, liver, and 
elsewhere do not always conform to the requirements for “FH. histolytica.” 
Cultures of amcebe answering more nearly the description given for 
“HB. coli” can, by methods described in this paper, be made to produce 
amcebic ulcerative colitis in man and monkeys and abscesses of the liver, 
‘omentum, spleen, and lungs in monkeys. In cultures, single species of 
amcebe are often found which are characterized by possessing a combi- 
nation of some of the features which have been described as distinctive 
for different species. Amoebe from many extraneous sources, and pre- 
sumably saprophytic, may be cultivated on artificial media, and with such 
cultures ulcerative amoebic colitis may be produced in man and animals 
and abscesses brought about in the liver, lung, omentum, spleen, and 
muscular tissues of animals. . 
"Oo 
