480 



PROTOZOA 



were reddening and swelling of the intestinal mucosa, chiefly of the 

 lower half of the large bowel, with here and there ecchymoses, small 

 superficial areas of necrosis, and shallow ulcerations. The mesenteric 

 glands and the solitary lymphoid follicles were often swollen. In the 

 blood-tinged mucus covering the mucous membranes amoebae were 

 found in greater or less numbers. Microscopic examinations showed 

 that the necrosis was limited as a rule to the mucosa, and that beneath 

 it the submucosa was thickened and cedematous and its vessels engorged; 

 there was also small-celled infiltration. Amcebse were found in the 

 borders of the ulcers, chiefly in the follicles of Lieberkiihn; in the base 

 of the ulcers they rarely penetrated more deeply than the upper layers 

 of the submucosa. With the amcebse were found many bacteria, chiefly 

 streptococci. 



Concerning the source of the amcebse and the mode of infection little 

 can be positively stated. It is reasonable to suppose, however, that 



FIG. 145 



Jfct, 



Jfn 



Jfn 



Leydenia gemmipara Schaudinn. A, single amoeba ; B, plasmodia and budding ; w, nucleus ; n', 

 nucleus dividing ; cv, contractile vacuole ; v, vacuole ; er, red blood cell ; Kn, buds ; Ka, amoeba 

 developed from bud. 



the mouth must be the usual path of infection, and that the amcebse 

 in all probability are taken in with the drinking-water and with un- 

 cooked vegetables. 



Methods of Examination. The stools must be examined in as fresh 

 a condition as possible. The bloody masses of mucus and the material 

 about them should be chosen to be examined. It may be necessary to 

 thin the particles examined with physiological salt solution. The warm 

 stage should be used and the cover-glass should be supported by small 

 feet of sealing wax. The collected material should be kept at body 

 temperature until time of examination. 



For permanent preparations Jager especially recommends the fol- 

 lowing method : For a fixative a concentrated watery solution of sub- 

 limate 100 c.c., absolute alcohol 50 c.c., acetic acid 5 drops. After 

 a few minutes' fixation wash carefully with iodine-alcohol, then stain 

 with Grenadier's hsematoxylin ten minutes, afterward wash with water 



