368 CLINICAL BACTERIOLOGY. 



solution or by Gram's method, the amebae will be found 

 regularly in the ulcers. They lie almost exclusively in the 

 submucosa, at times more deeply, upon the serosa. The 

 smaller forms, about \y 2 times or twice as large as white 

 blood-corpuscles, are constantly found in the intestinal wall. 

 They appear roundish, without a distinct nucleus ; their 

 bodies stain a deep blue, and vacuoles are often indicated. 

 In addition to the amebae, bacteria are always found in the 

 floor of the ulcer. 



In the intestinal wall also the amebae, as in the stools, 

 are only demonstrable when the tissues are subjected to 

 examination in a fresh state. At autopsies made four and 

 a half hours after death the amebae were present in the in- 

 testinal ulcers in enormous number, while at autopsies made 

 eighteen hours after death but few were present. 



Pathogenic Activity of the Amebae of Dysentery for 

 Animals. Dysenteric affections, with the evacuation of 

 hemorrhagic stools containing amebae, and with character- 

 istic ulcerative changes in the large intestine, in which also 

 amebae are present, have been induced experimentally in 

 large numbers of cats by injection of dysenteric stools 

 through the anus. Losch had induced dysentery in a dog 

 in the same way, by the introduction of large numbers of 

 amebae, both by the mouth and by the anus. In other 

 animals, however, infection has thus far not been in- 

 duced. It is noteworthy that Quincke and Roos ob- 

 served that of four cats that received by the mouth exclu- 

 sively stools containing amebae, with an abundance of the 

 encysted varieties, two were seized with typical amebic 

 enteritis. The encysted varieties thus appear to be able to 

 escape the action of the hydrochloric acid of the stomach. 



Occurrence of Bacteria in Dysentery. In amebic 

 stools, in addition to amebae, bacteria are always present ; 

 and especially and in preponderant number, streptococci ; 

 not rarely, also the bacterium coli ; and, further, the 

 bacillus pyocyaneus, staphylococci, etc. In the intestinal 

 wall also the amebae are found constantly in association with 

 bacteria, and here bacilli rather than streptococci are present. 

 The bacteria lie within and around the amebae. At times 

 they penetrate independently into the tissues, and more 

 deeply than the amebae. The association of bacteria and 

 amebae occurs with such regularity that some connection 

 must exist between the two. It is possible that the condi- 



