76 PARASITIC AMOEBA OF MAN. 



the examination of healthy American soldiers sta- 

 tioned at San Francisco, California. The examina- 

 tions were made largely among the members of the 

 Hospital Corps of the U. S. Army, recruited from 

 almost every portion of the United States, and who 

 were on duty at the General Hospital, and under 

 constant observation. Over 200 men were examined 

 and it was found that, after the administration of 

 magnesia sulphate in ounce doses, the f eces of 65 per 

 cent, showed the presence of Entamceba coll., although 

 in many instances repeated examinations were neces- 

 sary in order to demonstrate the parasite. It is the 

 writer's belief that the small percentage of positive 

 results in the demonstration of this parasite, reported 

 by some observers, are due to the examination of only 

 one or two preparations. At least eight specimens 

 should be examined before one can be sure that En- 

 tamoeba coli is absent. 



Believing that geographic distribution might have 

 something to do with the proportion of infected in- 

 dividuals, the locality from which each individual 

 came was ascertained, but there was apparently no 

 great variation due to this cause. However, this 

 negative result cannot be considered as conclusive and 

 the question can only be settled when we have data 

 concerning the examination of a large number of in- 

 dividuals in different localities. All the men examined 



