146 PARASITIC AMCEB.E OF MAN. 



membrane into the lumen of the intestine. The 

 mucous membrane covering them is generally in- 

 flamed, and when incised they are found to contain a 

 yellowish or a greenish-yellow viscid fluid of a 

 gelatinous consistence, which, upon microscopic ex- 

 amination, is seen to be composed of degenerated cel- 

 lular material, mucus, and actively motile amoebae. 

 These nodular elevations mark the situation of the 

 ulceration which develops later. 



The next stage of amoebic dysentery is indicated 

 by the appearance of small ulcers formed by the 

 necrosis of the mucous membrane covering the nodu- 

 lar elevations just mentioned. The base of these 

 ulcers is surrounded by inflamed mucous membrane, 

 while the edges are ragged in appearance, and the 

 floor, situated in the submucous coat of the intestine, 

 is covered with the gelatinous material which has been 

 described. The ulcers spread by invasion of the sur- 

 rounding structure both laterally and downward, be- 

 coming larger and larger, finally reaching the muscu- 

 lar coat of the intestine. In some instances the small 

 ulcers are pretty generally distributed and all of 

 about the same size, but in a majority of cases both 

 the small and large ulcers occur together, and in 

 many cases one may trace the entire pathology of the 

 disease, from the initial lesion, represented by the 

 intact nodular mass, to the large ulcer involving all of 

 the coats of the intestine. 



