278 2^^^ Philippine Journal of Science ms 



American soldiers and in 72 per cent of Filipino scouts in the 

 Philippine Islands. These figures for the Phihppines have been 

 confirmed by Craig and Ashburn who found 71 per cent of 

 healthy American soldiers parasitized. Evidence of the wide 

 distribution of Entamoeba coli is further substantiated by Mc- 

 Carrison in India, by Wenyon (1908) in Khartum, by Elmas- 

 sian (1909) in South America, by Whitmore (1911) in Manila 

 and Saigon, by Prowazek (1911) in Samoa, and by Darling 

 (1912) upon the Isthmus of Panama. 



Recently several other entamoebas of the coli type have been 

 described as distinct species. Prowazek (1911) found asso- 

 ciated with Entamoeba coli in human fseces in Suwaii and Sai- 

 pipi an entamoeba which he called Entamoeba williamsi. This 

 species is said to differ from Entamoeba coli in the presence 

 of "excretion crystals" in its cytoplasm, in its movements and 

 feeding habits, in its peculiar chromidia formation, and in that 

 it develops cysts containing 10 instead of 8 nuclei. 



Beaurepaire Aragao (1912) describes an entamoeba from the 

 stools of a child in Brazil which is said to differ from Entamoeba 

 coli by the presence of a bundle of "siderophile substance," some- 

 times double, which divides the cyst into two approximately equal 

 parts. The author designates this entamoeba by the name Enta- 

 moeba brasiliensis. 



Prowazek (1912) found another entamoeba associated with 

 Entamoeba coli in the stools of a woman in Sawaii, which he con- 

 siders a distinct species, and which he named Entamoeba hart- 

 manni. This entamoeba is said to differ from Entamoeba coli in 

 its small size, in the variable size of its nuclei, and by the very 

 characteristic minute chromidia in the cytoplasm. 



It is noteworthy that 2 out of these 3 so-called species have 

 been found but once, that 2 out of the 3 have been found asso- 

 ciated in the same patient with typical Entamoeba coli, and that 

 all 3 were found in regions where infections with Entamoeba 

 coli are common. The differential characters of these so-called 

 new species consist chiefly in differences in size and cytoplasmic 

 contents, variable size of the nuclei, and the number of nuclei 

 in the cyst. Such differences are not uncommon mingled with 

 typical coli forms. Abnormally large or small coli are frequently 

 met with, and within certain limits the size of the nuclei and the 

 cytoplasmic contents of entamoebse are exceedingly variable. 

 These variations represent chiefly metabolic and reproductive, 

 but sometimes degenerative, changes in the entamoeba. The 

 number of nuclei in the cysts of Entamoeba coli is also subject 



