734 



PATHOGENIC PROTOZOA 



points to the importance of contact, and perhaps flies, as the chief 

 agents in its spread. Extreme cleanliness among the servants and in 

 the kitchen will prevent the transfer of histolytica cysts from the ill 

 to the well. The disease has disappeared from the Panama Canal 

 Zone, where it formerly was common, since the introduction of good 

 water and sewer systems and better hygienic conditions. 



ENDAMEBA COLI (Loesch emend. Schaudinn) 



(Endameba nipponica [Koidzumi, pro parte] and possibly 

 Endameba minuta [Elmassian]) 



This is a harmless parasite of man, and its presence in stools, at 

 one time, gave rise to much confusion, and in the minds of many, 



threw doubt upon the ex- 

 istence of a form of dys- 

 entery due to ameba, since 

 it was found not infre- 

 quently in healthy individ- 

 uals. Schaudinn found it 

 present in the stools of 

 fifty per cent of the per- 

 sons examined in East 

 Prussia, in Berlin in 

 twenty per cent, and in 

 Istria in sixty per cent. 

 Craig, and Craig and Ash- 

 burn found it present in 

 176, or fifty-eight per cent, 

 of 307 examinations of 

 healthy American soldiers. 

 Craig was able to follow* 

 some individuals for four 

 to six years, during which 

 time they constantly 

 showed Endameba coli in the feces, yet never developed dysentery. 

 The organism seems to be found in all countries, regardless of climate. 

 Its recognition and separation from histolytica we owe to Schaudinn, 

 Jiirgens, Craig and others. 



In size it varies from ten to forty microns, the average being be- 

 tween twenty and forty. The ectoplasm is never seen except during 

 movement, and it is then hyaline, and only slightly refractile, and 



FIG. 163. ENDAMEBA COLI. Small precystic 

 form. (Army Med. School Collection, Wash- 

 ington, D. C.) 



