698 Dysentery 



numbers of amebas abound. The liver sometimes becomes 

 adherent to the diaphragm, may perforate it, and after ad- 

 hesion of the lung to the diaphragm may evacuate through 

 the lung, the pinkish abscess contents with amebas being 

 expectorated. 



m ***.: 



</ 



q l 



^^a. 



W 



% 





W 



v 

 X 



Fig. 233. Entamoeba histolytica. Section of the human intestinal 

 wall showing the amebas at the base of a dysenteric ulcer: A, A, A, 

 Amebas, some of which are in blood-vessels, Gf (Harris). 



Sections of the intestinal wall and of the liver near the 

 border of the abscess show the amebas well when stained 

 with iron-hematoxylon, or perhaps still better by Mallory's 

 differential method.* 



1. Harden the tissue in alcohol. 



2. Stain sections in a saturated aqueous solution of thionin three to 

 five minutes. 



3. Differentiate in a 2 per cent, aqueous solution of oxalic acid for 

 one-half to one minute. 



4. Wash in water. 



5. Dehydrate in absolute alcohol. 



6. Clear in alcohol. 



7. Xylol-balsam. 



The nuclei of the amebas and the granules of the mast-cells are 

 stained brownish red ; the nuclei of the mast-cells and of all other cells 

 are stained blue. 



*" Pathological Technic," 1911, p. 434. 



