158 PARASITIC AMCEBJE OF MAN. 



scope showing only from one-half dozen to a dozen. 

 Amoebae are not always found in the contents of the 

 liver abscesses, especially in the older ones, but gen- 

 erally scrapings from the walls will demonstrate 

 them. In the abscesses in which there is a mixed 

 infection, pus corpuscles are found as in ordinary 

 pus, together with various bacteria, chiefly micrococci. 

 The contents of the liver abscess may be sterile 

 except for the amoebae, or there may be a mixed in- 

 fection with various bacteria. In the smaller abscesses 

 it is generally found that the pus is sterile, while in 

 the large there is generally a mixed infection. There 

 has been considerable discussion as to the relative 

 importance of amoebae and bacteria in the production 

 of these liver abscesses, some authorities claiming that 

 the condition is produced entirely by the amoebae, 

 while others insist that it is due to a mixed infection. 

 At the present time, however, it is generally conceded 

 that amoebae are capable of producing in the liver the 

 characteristic form of abscess which I have described, 

 and that when there is a mixed infection the abscesses 

 lose their characteristic features and resemble those 

 found in other portions of the body. The amoeba 

 undoubtedly produce the abscesses primarily, but they 

 afterward become infected with other organisms, 

 especially streptococci, staphylococci, and Bacillus 

 coli communis. An examination of the contents bac- 



