THE ANIMAL PARASITES OF MAN 



enteritis in China. On the evening of the third day the cat evacuated blood-stained 

 mucous faeces which contained large numbers of typical Entamceba histolytica. On 

 the fourth day after the infection the animal experimented upon died, and the large 

 intestine showed the changes previously stated. 



E histolytica also is found in the large intestine. This was originally shown 

 to be the case by Kartulis, and the fact has recently been confirmed from many 

 quarters. It is also present in the metastatic abscesses of which it is the cause 

 (cf. among other authors, Rogers, Brit. Med. Jonrn., 1902, ii, No. 2,177, P- 844 ; and 

 1903, i, No. 2,214, P- i3!5)- 



It should lastly be pointed out in this connection that mixed infections also take 

 place. For instance, in addition to E. histolytica, E. coli, and, under certain circum- 

 stances, flagellates may be found together. In the same way E. colt may come 

 under observation even in bacillary dysentery. On the other hand, Schaudinn 

 stated that in cases of dysentery endemic in Istria, Entamceba colt, if it had hitherto 

 been present, disappeared, to return again after recovery from the illness. 



FIG. 8. Entamcrba histolytica. a, trophozoite (tetragena type) containing red blood 

 corpuscles, x 1,300 ; b and c, two isolated nuclei showing different appearances of karyosome, 

 centriole and nuclear membrane, x 2,600. (After Hartmann.) 



(Entamceba tetragena, Viereck, 1907.) 



This amoeba must now be considered to be a part of the life- 

 cycle of Entamceba histolytica, in fact a very important part of that 

 cycle, especially in its tetranucleate cystic stages. 



This organism, the so-called Entamceba tetragena, may occur in 

 the human intestine in cases of amoebic dysentery, especially in 

 mild or chronic cases. It was discovered by Viereck in 1907 in 

 patients suffering from dysentery contracted in Africa. Soon after- 

 wards an independent description was published by Hartmann, who 

 called the amoeba E. africana. It was also studied by Bensen and 

 Werner. Recently (1912-13) much work has been published on 

 this amoeba by Darling and others ; in this way its relationship to 

 Schaudinn's E. histolytica has been made known. 



In general morphology it somewhat resembles Entamceba coll, and 



