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W. GLEN LISTON AND C. H. MARTIN. 
of small amoeba-cysts. The two other kittens were injected 
per rectum, the one with an emulsion of large amoeba-cysts, 
the other with an emulsion of small amoeba-cysts. On the 
following day, as well as on the third day after treatment, 
the stools were examined both microscopically and by 
cultures for the presence of living amoebae, but none were 
found. The kittens were healthy a fortnight later. These 
physiological tests were, then, unsuccessful in demonstrating 
any pathogenic properties in either species of amoeba found 
in the liver-abscess culture, and they also failed to distinguish 
the one species from the other. Too much stress, however, 
cannot be placed on the failure of these experiments, not 
only because of their small number, but especially when the 
complicated conditions which are associated with the living 
together of bacteria and amoebae are kept in mind, and to 
which some reference will be made later. Nevertheless, the 
negative results of these experiments are in conformity with 
the more numerous ones carried out by Noc and reported by 
him (2). By way of contrast, I found it interesting to study 
sections of the large intestine of a cat v which had been 
infected with dysentery by the rectal injection of the stools 
of a patient suffering from dysentery in the Straits Settle- 
ments. This material was kindly supplied to me by Dr. 
Ledingham. Sections of this tissue showed well-marked 
dysenteric lesions associated with the presence of amoebae, 
the amoebae being found together with bacteria, not only 
in the mucosa, but penetrating into the submucosa in 
the neighbourhood of the ulcerations. It is interesting to 
compare the morphological appearance of these amoebae with 
those found in the cultures. In the first place, the amoebae 
in the sections of the cat’s intestine were considerably larger 
than even the larger type found in my cultures. The nuclear 
structure of these amoebae, too, differed remarkably from 
that of the amoebae of the cultures. Thus, while the 
chromatic substance of the nucleus of the cultural amoebae 
was abundant and differentiated into a large central portion 
and a thin peripheral layer, the chromatic substance of the 
