124 THE ANIMAL PARASITES OF MAN 



ileum. In the case of four cats suffering from entero-colitis, into 

 which human faeces containing balantidia were introduced per os, 

 balantidium cysts were found in the faeces three days after the 

 last ingestion ; great numbers, moreover, were found in the caecum 

 and the posterior part of the small intestine at the autopsy of 

 the animals which died about eight days after the commencement 

 of the experiment ; actual colonisation, therefore, was not achieved 

 in either series of experiments. Free or encysted balantidia of 

 pigs were used for further experiments. The experiments proved 

 negative when faeces containing cysts were injected into the rec- 

 tum of healthy cats (three experiments), or cats (two) suffering 

 from spontaneous intestinal catarrh, or when such material was 

 introduced per os into three healthy cats. In the case of two 

 cats with intestinal catarrh artificially produced, a small number 

 of the non-encysted balantidia injected into the rectum remained 

 alive ; larger quantities of faeces containing encysted balantidia 

 were introduced into two other cats affected with the same com- 

 plaint ; these, certainly, did not appear in the fasces, but small 

 numbers, free and alive, were found in the caecum. Similarly 

 encysted balantidia were introduced into two cats with dilated 

 rectum, and whose faeces had an alkaline reaction ; in these cases 

 also no parasites appeared in the faeces, but three and five days 

 later, when the two animals were examined, a very small number 

 were discovered free in the large intestine. 



These experiments teach us that human faeces and the faeces 

 of pigs have a different effect on cats, moreover, that they are 

 neither pathogenetic to these animals nor capable of influencing 

 intestinal diseases, artificial or spontaneous, and finally that even 

 when not encysted they pass through the stomach of cats unin- 

 jured when introduced with large quantities of faeces of an alkaline 

 reaction. It stands to reason that this mode of infection cannot 

 be considered as a means of transmission to man. 



LITERATURE. 



MALMSTEN, P. H. Infusorien als Intestinalthiere b. Mensch. (Virch. Arch., 1857, 



xii., p. 302.) 

 SHEGALOW, J. P. Ein Fall v. Bol. coli bei einem 5 jahr. Madch. (Jahrb. f. Kdrhlkde., 



1899, xlix., p. 425)- 

 JANOWSKI, W. Ein Fall v. Bol. coli im Stuhl (Ztschr. f. klin. Med., 1897, xxxii., p. 



415). (A complete list of the literature is given by Janowski, Shegalow and 



Solowjew.) 



COLLMANN, B. 5 Falle v. Bol. coli i. Darm d. Mensch. In. Diss. Kgsbg., 1900. 

 MAGGIORA, A. Micr. u. bact. Beob. wahr. ein. epid. dys. Dickdarmentziind. (C. f. 



B. u. P., 1892, xi., p. 181). 

 SOLOWJEW. Bol. coli als Erreg. chron. Durchf. (C. f. B., P. u. I., 1901 [i], xxix., pp. 



821, 849). 



