PLASMODROMATA AND SARCODINA 



attack of dysentery, the chromatin in and around the nucleus becomes 

 diffused into the cytoplasm, and finally collects near the periphery, and the 

 remains of the nucleus disappear, being either pushed out or absorbed. The 

 ectoplasm forms small knobs, containing several chromidia in each. These 

 knobs and their chromidia become separated off as rounded bodies, which, 

 becoming surrounded with a yellowish-brown envelope, form the spores for 

 the infection of a new host, as has been shown by Schaudinn's feeding experi- 

 ments on cats, which developed typical dysentery with the amoebae in the 

 motions, in the lumen, and in the wall of the alimentary canal. These experi- 

 ments further proved that it was only by the spores that infection would be 

 spread . The remaining portion of the amoeba dies after the formation of the 

 spores. 



Recent Work.- — Modern researches tend to confirm Schaudinn's 

 morphological description as well as his binary fission, but not the 

 amitotic form of division, while the bud form^ation (Fig. 52) has 

 been proved by James and others to be artificial, and the spores 

 are regarded as not belonging to an Amoeba, but to some other 

 organism in the faeces. 



In 1905 Craig in the Philippine Islands confirmed Schaudinn's 

 morphological characters, and called attention to the rapid move- 

 ments of L. histolytica and to the greenish 

 tint which it often assumes in motions 

 containing much blood. 



In 1907 Viereck stated that there were 

 more than one pathogenic amoeba in man. 

 The second one, which he named Ent- 



■p^^ ^2 Artificial ^^^^^ tetragena, looked like L. coli, but 



Budding in Loeschia ^'^^ only four-nucleate cysts, and this, he 

 histolytica Schaudinn, thinks, is the type seen by Quinke and 

 m Moist Qhamber Rqos and by Kruse and Pasquale. In the 

 Preparations. same year Hartmann and von Prowazek 



(After James.) found an entamoeba in patients coming 



from Africa, which could be differentiated 

 by its nuclear structure from L. coli and L. histolytica, and this 

 they named E. africana ; but later Hartmann, finding quadri- 

 nucleate cysts, concluded that it was the same as E. tetragena, 

 which is an accepted fact. 



In 1908 Craig, drawing attention to variations in L. histolytica 

 and in L. coli, emphasized the difficulty in differentiation between 

 these organisms, and in the same year Werner confirmed the exist- 

 ence of L. histolytica and of E. tetragena. 



In 1909 Hartmann states that Schaudinn knew about E. tetragena, 

 and that of the three, L. coli, L. histolytica, and E. tetragena, 

 L. histolytica is the smallest, and has ectoplasm differentiated from 

 endoplasm even at rest. Its nucleus is excentric, can be distorted 

 and does not possess a double contoured achromatic membrane, 

 while its lack of chromatin is characteristic, there being only 

 little karyosome and a condensed layer of chromatin at the margi 

 of the nucleus, while nuclear cyclical changes are rare. In the 

 same year Noc wrote a paper mainly of an epidemiological 

 nature, but also dealing with this amoeba, and Elmassian described 



