644 APPENDIX. 



Numerous investigations have demonstrated conclu- 

 sively that amoebae may be present in the feces of 

 healthy persons. They have also been found in cases 

 of chronic diarrhoea, cholera, intestinal tuberculosis, 

 typhoid fever, hemorrhoids, and other diseases; chiefly 

 in such as are accompanied by looseness of the bowels. 

 Some of the cases cited as chronic enteritis or chronic 

 diarrhoea were in all probability examples of the more 

 chronic form of amoebic dysentery, but not all of them, 

 of course. Temporary looseness of the bowels in other- 

 wise healthy persons, either as the result of slight indis- 

 position or of medication, seems to be a condition of the 

 presence of amoebae in the stools. Thus, Schulberg 

 found these organisms in ten out of twenty loose stools 

 produced by the administration of Carlsbad salts, and 

 concluded that the amoeba is a normal and harmless 

 parasite of the intestines, the reason for its non-appear- 

 ance in ordinary fecal evacuations being the solidity and 

 acid reaction of the contents of the lower bowel, which 

 soon destroy it. The question naturally arises whether 

 more than one species of amoeba is found in the human 

 intestinal tract. So far no definite morphological dif- 

 ferences ha ye been found between the amoeba occurring 

 in the stools of healthy persons and that Jn patients 

 suffering from dysentery; nor can any deductions be 

 drawn from the attempts to cultivate the amoeba, for no 

 one yet has succeeded in producing pure cultures of it. 



Pathogenesis. It is evident that, in the absence of 

 artificially produced pure cultures of amoebae, inocula- 

 tion experiments must be made wtih material such as 

 dysenteric stools or the contents of hepatic abscesses. 

 In a few cases such material from hepatic abscesses 

 which was found to contain no organisms other than 



