10241 



Kesscl: Amoebae of Culture Rots and Mire 



511) 



decumani from mouse to mouse and from mouse to rat, faeces were 

 fed from the same mouse to both the mice and the rats. As the result 

 ■was positive in rats and negative in the mice, the indication is tliat 

 the reason for the negative results in the mice is to be traced to some 

 condition M'ithin the mice rather than to a non-viable condition of tlie 

 cysts. In transferring C. muris from mouse to mouse and from mouse 

 to rat, faeces from the same mouse were used to feed both the rats and 

 mice. As similar results were obtained in this experiment as in the 

 previous one with reference to non-infection of the mice, similar 

 conclusions are applicable. 



TABLE 7 



Table Showixg Results of Experiments in CROSs-lNrECTiox op C. muris and 



C. decumnni from Rats to Mice axd from Mice to Rats 



* This ease of mixed infection is thought to be due to a positive infection of 



t'. (hciinwni whicli was overlooked in the examination with epsom salt. 



The facts that C. decumani has been successfully transferred from 

 rats to rats and from mice to rats without any perceptible morpho- 

 logical change, and that C. muris has also been transferred from rats 

 to rats, from mice to rats, and from rats to mice without a morpho- 

 logical change, are further evidence in favor of the constancy of the 

 characters upon which both of these species are established. 



