RHIZOPODA 425 



animals by injecting feces containing amebse into the rectum or, 

 by feeding fecal material containing cysts; and further, the fact 

 that abscesses occur in the liver in amebic dysentery, in which the 

 amebae are present and in which it has been impossible to demon- 

 strate the presence of bacteria. The causal relation seems highly 

 probable, but it must be recognized that the evidence is very in- 

 conclusive and admits of other possible explanations. Even 

 the relationships of the various forms seen in the microscopic 

 preparations require a certain amount of speculation for their 

 determination, and the possibility of error, even by the experienced 

 protozoologist, must be recognized and has been' well illustrated 

 by the divergent views of Schaudinn and of Hartmann in study- 

 ing the same slides. Greater certainty , would doubtless be 

 derived from the study of artificial cultures if such could be made 

 available. 



Numerous cultures of amebae have been obtained from the 

 stools of cases of dysentery, and some from the pus of amebic 

 abscesses of the liver, the growth taking place on agar in the pres- 

 ence of a single . species of bacteria. With these cultures it has 

 been possible to cause enteritis in monkeys. Such cultures have 

 also been grown at 37° C. by A. W. Williams^ in pure culture on 

 agar streaked with brain substance and with blood, and in these 

 cultures she finds that the am abas approach in their structure 

 the tjqjical endamebse, not only in nuclear structure and cyst 

 formation, but also in the utiHzation of red blood cells as food. 

 WMtmore^ has carefully studied a number of cultures of amebae 

 obtained from case? of dysentery, one of them from a liver abscess, 

 and has concluded that in every instance the amebae were free- 

 living saprophytic forms belonging to the genus Amoeba and not 

 in any case parasitic species. 



' Soc. Amer. Bact., New York Meeting, Jan. 2, 1913. Science 1913, Vol. 

 XXXVJII, p. 451; Williams, A. W., and Calkins, G. N., Journ. Med. Rsch., 1913, 

 Vol. XXIX, pp. 43-S6. 



^Archivf. Protistenkunde, 191 1, Bd. XXIII, S. 71-80; ibid., pp. 81-95. 



