172 RESEARCH IN PROTOZOOLOGY 



found to grow best at temperatures between 28° and 30° C. He 

 obtained cultures from six stools in cases of acute amoebic dysen- 

 tery and was successful, in one instance, in keeping the cultures 

 going for several weeks, subcultures being made every day. The 

 reader is referred to Cutler's paper for details regarding his work 

 and, although Dobell (1919), because he was unable to confirm 

 Cutler's results, does not believe he actually cultivated E. histolyt- 

 ica, there is very good reason to believe that he was successful in 

 this respect. Wenyon (1926) and Knowles (1928) both state 

 that Cutler was probably successful in cultivating this parasite, 

 so that it is most probable that to Cutler belongs the credit of 

 having first obtained E. histolytica in cultures and of having main- 

 tained such cultures for several weeks. 



While there may still be some doubt of Cutler's success in the 

 cultivation of E. Jiistolytica there is none at all in that of Boeck 

 and Drbohlav, who, in 1925, published their results in this respect 

 and gave to the protozoologist a simple and successful method of 

 cultivation of this important parasite. Their work proved con- 

 clusively that this parasite can be cultivated and that the amoebae 

 in the cultures are capable of producing typical amoebic dysentery 

 in kittens accompanied by the characteristic lesions of the infec- 

 tion. These investigators cultivated this amoeba from the feces 

 of two patients with amoebic dysentery whose stools were free 

 from other intestinal protozoa. The first successful culture was 

 obtained in Locke- Egg-Serum medium while cultivating the stools 

 of one of the patients for other intestinal protozoa. This strain of 

 the parasite was continued in cultures for over eight months and 

 through 152 subcultures. 



The work of Boeck and Drbohlav was soon confirmed by many 

 protozoologists and there have been many modifications of their 

 culture media and technique. For the cultivation of E. histolytica 

 many media have been recommended and the most useful and 

 important of these will now be considered. 



CULTURE MEDIA FOR ENDAMCEBA HISTOLYTICA 



Boeck and Drbohlav s Media. The two following media have 

 been found efficient in the cultivation of this parasite by Boeck 

 and Drbohlav (1925) : 



Medium No. i. Locke-Egg-Serum, or L.E.S. Medium. Four eggs are 

 washed, brushed with alcohol and broken into a sterile flask containing glass 



