264 ' WALKER. 



■and life-cycle from' Entamoeba coli, Eritamceha histolytica, 2in& Entamaihu tetra- 

 -gina. Noc believes this amoeba to be the ca-use of the amoebic dysentery and 

 liver abscesses of that country. The cysts of this amoeba, he says, are especially 

 abundant in the surface waters of Indo China during the rainy season which 

 corresponds with the exacerbation of endemic dysentery. However, he was unable 

 to produce dysentery in kittens or monkeys with his cultures from water or dysen- 

 teric stools. 



Werner (1908) was unable to obtain vegetative forms of either Entamoeba 

 histolytica or Entamozba tetragina, but did secure growth and cyst formation of 

 Amosba Umax, a common water amoeba, in his cultures from dysenteric stools on 

 Musgrave and Clegg's medium. Therefore, he is of the opinion that the amoebae 

 cultivated by Musgrave and Clegg (1904), Walker (1908), and others from the 

 intestinal tract of man and other animals are cysts of similar free-living amoebae 

 which have been ingested with water or food, have passed unchanged through the 

 intestine, and have found conditions favorable for development when the faeces 

 have been placed on the culture medium. 



Whitmore (1911) has also come to the conclusion that the amoebae cultivated 

 by him at Manila from dysenteric stools are free-living amoebae of the Umax 

 type and not parasitic amoebae. 



AM(EBJ3 IN THE MANILA WATEK SUPPLY. 



In. consideration of the somewhat general belief in the Orient that 

 the axnoebge in the water are the source of infection in amoebic dysentery, 

 and in consequence of the cultural and experimental work of Noc 

 (1909) Williams and Gurley (1909), and especially of Musgrave and 

 Clegg (1904), who state that they have produced dysentery in monkeys 

 and man with amosbse cultivated from the Manila water supply, it has 

 seemed desirable that a study be made of these for comparison with 

 those found in the intestinal tract of man. 



The Manila water supply comes from an uninhabited watershed of the Mari- 

 quina River and its tributaries. The water is stored in a reservoir on the water- 

 shed by a dam constructed across a narrow gorge in the Mariquina Valley at 

 Montalban about 24 kilometers from Manila. It is conducted from this reser- 

 voir in closed water-mains to Manila, where it is distributed in branch mains 

 and pipes to the various taps in the city. The water, therefore, is presumably 

 free from faecal contamination and should contain only the normal amoebic fauna 

 of that watershed. 



Samples of this water have been collected at different times from different 

 taps in Manila for examination. In each case about 200 cubic centimeters of 

 the water have been drawn directly from the tap into a sterile Erlenmeyer flask 

 and about 2 cubic centimeters of ordinary nutrient bouillon added to enrich it 

 and favor the multiplication of organisms present in the sample. The flasks, 

 plugged with sterile cotton, were kept at room temperature and the contents 

 examined from day to day for amoebae. In two or three days a scum forms on 

 the surface of the water which, if examined microscopically, will be found to 

 consist of bacterial and protozoan growth, among the latter amoebae are usually 

 present. If a loop-full of this material containing amoebae be transplanted to 

 the surface of solidified Musgrave and Clegg's medium in a Petri dish an abundant 

 growth of amoebae will be obtained in a few days. 



