190 PARASITIC AMOEBA OF MAN. 



several minutes, after which the conjugants separated, 

 but again became attached and the process was re- 

 peated. After about half an hour final separation 

 occurred, the organisms moving off to different 

 portions of the microscopic field. 



A similar process has been observed by Werner 

 and he considers that one of the conjugants appears 

 clearer than the other and that it is possible to thus 

 distinguish them. 



CULTIVATION. Attempts to cultivate Entamoeba 

 tetragena have always resulted in failure, although 

 the most careful work upon this subject has been 

 done by Viereck, Hartmann and Prowazek, and 

 Werner. Regarding cultivation, Werner says: 



" In no case did I succeed in causing a multiplica- 

 tion of the vegetative forms of histolytica or tetragena 

 that were present in the infective matter. But on 

 the other hand, I often found growth and encystment 

 of Amoeba Umax, on the culture material, and from 

 Musgrave and Clegg's illustrations I am convinced 

 that these observers, as well as Walker, who obtained 

 his cultures from them, grew nothing but Amoeba 

 Umax on their culture material, and that it is this 

 that they have described. It is certain that by cats, 

 and probably man, the encysted forms of Amoeba 

 Umax are often swallowed with the food, and traverse 



