732 



PATHOGENIC PROTOZOA 



nuclei, and the presence of these four nucleated cysts is pathognomonic 

 of the disease. They may be found most abundantly, not in the small 

 amount of mucus which may adhere to the formed f eces, but in surface 



scrapings from the fe- 



Pcal mass. In addition 

 to the four small ring- 

 like nuclei, the cysts 

 contain few or many 

 clumps of chromatin ; 

 these in total mass may 

 be many times greater 

 than the nucleus, and 

 it is impossible, there- 

 fore, that they are 

 simply extruded from 

 the nucleus; evidently, 

 the chromatin grains, 

 while in the cytoplasm, 

 increase in size and 

 number. In hematoxy- 

 lin stains no structure 

 in these masses is dis- 

 cernible and their func- 

 tion is unknown; after 

 a time they disappear 

 and one finds cysts quite free of them. The presence, however, of 

 many large chromatin masses in the cysts is characteristic of Enda- 

 meba histolytica. 



Fertilization inside the cyst has not been demonstrated, but it is 

 possible that the four young amebae, liberated from the cyst when in- 

 gested by a new host, are garnets, and that conjugation takes place 

 between them, as in the case with Endameba blattaB. 



The treatment of amebic dysentery, to be effective, must be radical 

 and persistent, and may be compared to the treatment of malaria with 

 quinine. For many years the English in India, with a few followers 

 in other parts of the world, had treated dysentery with ipecac in mas- 

 sive doses, with wonderful results in some cases and failure in others. 

 The treatment was quite disagreeable and not entirely satisfactory. 

 Vedder, in 1911, examined the various alkaloids of ipecac and found 

 that emetin was strongly amebacidal, and he recommended its use for 





FIG. 161. ENDAMEBA COLI. (Army Med. 

 Collection, Washington, D. C.) 



