554 
The specific cause of this type of liver abscess is Ameba colt, either 
acting alone or in association with certain other micro-organisms. ‘These 
parasites are constantly present in the contents or walls of true amebic 
abscesses and no apparent differences are found between the amb 
encountered here and those seen in the intestine. They may be the only 
organisms to be observed in the abscess at any time, or both amoebe and 
bacteria may be present throughout the course of its growth, or, again, 
bacteria may be associated with amcebe in the early lesions only to 
disappear at a later period. Both ameebx and bacteria are often in the 
end not found in the contents of abscesses in which they were present at | 
the beginning. Frequently the bacteria produce alterations, particularly 
in the nature of the lesion, so that it ultimately may more closely resemble 
a bacterial abscess. The bacteria which are encountered are of several 
different varieties. S. pyogenes aureus and B. coli are the most frequent ; 
streptococci, pneumococci, B. pyocyaneus and several others have occa- 
sionally been found. 
Bacteria are much more commonly associated with amcebe in multiple 
abscesses than they are in solitary ones. This fact has been pointed out 
by Rogers and others and these observations are confirmed by the findings 
in the Philippine Islands. Multiple abscesses, sterile according to culture 
and animal inoculation, are occasionally met with, but this occurrence is 
much less frequent than it is in the large, solitary ones. In consider- 
ing the reasons for this condition, several circumstances must be taken 
into consideration. Multiple abscesses are usually smaller and of shorter 
duration than are the single ones, and it is probable that, were oppor- 
tunity offered at an early stage for bacteriologic study of solitary ab- 
scesses, more of them would show bacteria. In fact, to judge from the 
behavior of amcebe on artificial media, it would hardly seem as if these 
organisms would be able to reach the liver, free from bacteria. No doubt, 
multiple abscesses are usually transmitted through the portal vessels, 
and under these circumstances bacteria within and attached to the amcebe 
have a better opportunity of living and of multiplying than they would 
in some of the cases in which they probably reach the liver by directly 
continuous tissue. 
A determination of the time of development of liver abscesses with 
reference to the bowel infection is not possible in the majority of 
instances. This is largely due to the slow development and absence of 
early symptoms in both diseases, however, the evidence tends to show that 
abscess may develop at any time during the intestinal infection. The 
literature on liver abscess in dysentery contains references to abscesses 
which have developed from a few days’ time after the onset of the dysen- 
tery to those in which the affection was first diagnosed twenty-one years 
after the beginning. These records are based upon clinical evidences as 
given by the diagnosis of both the disease of the colon and of the liver, 
and therefore they are absolutely valueless in determining the only 
