553 
and in other situations at considerable distances from the macroscopic 
lesions. In addition, amcebe have been reported as occurring in emboli 
in the portal veins, and since this fact was first pointed out by Council- 
man and Lafleur and other observers, I have found it to be true in two 
instances, and in neither of these was there abscess or other indication 
of gross amoebic infection of the liver. Therefore, the evidence seems 
to be conclusive that in the majority of cases of well-advanced intestinal 
infection, amcebw must almost constantly be carried to the liver, and this 
is particularly true in respect to those in which the thrombosis and 
endarteritis are modified by secondary invaders. If this is so, then 
actual liver infection must, at least partially, depend upon changes in 
that organ itself. However, in accepting such a tentative conclusion, 
a few other considerations must be advanced. The first and most 
important of these, namely, the influence of environment or symbiosis 
on the pathogenic action of amcbex, has already briefly been dealt with 
by Musgrave and Clegg. From this work and since that communica- 
tion, from experimental data which we have obtained with cultures of 
amoebe, it seems fairly established that these organisms are amenable 
to changes of environment which at first they would not easily tolerate. 
When such a change has been made, they are brought back to the original 
symbiosis with an equal amount of difficulty. The power of an ameba 
to propogate under new conditions may, to a large extent, depend upon 
the similarity between its new environment and the former one and 
also possibly, although this has not been proved, upon its ability to 
produce lesions in the tissues. If this should be true of intestinal 
infections it might be equally so of those of the liver, and the occurrence 
of liver abscess would then depend, as it apparently does, not so much 
upon whether amcebe reach the liver or not, but upon whether or not 
the liver environment had, by both previous and present sub-intoxication, 
caused by the intestinal environment (see Adami’s articles), been brought 
to a condition approaching that of the bowel in which the amcbe were 
acting. This question is an extremely important one because in its 
answer by the use of cultures lies the possibility of an explanation of the 
exact mode of action of amcebe in producing pathologie lesions. For 
work of this class the liver is a much more suitable organ than the 
intestine, because of the large variety of bacteria and other unknown 
influences in the latter. At present all of my work being carried on 
in conjunction with M. T. Clegg, of this laboratory, and in St. Paul’s 
Hospital is in the direction indicated above, but the results so far obtained 
do not justify further statements. 
Mouton, working with cultures of amcebe, opened up another approach 
to this subject by studying the action of various serums upon “amba 
diastase.” 
“Publications Biological Laboratory, Bureau of Government Laboratories, Ma- 
nila (1904), 18, 1. 
