THE BACTERIOPHAGE IN THE HEALTHY INDIVIDUAL 231 



of isolating these bacteria may be due solely to this phenomenon 

 of commensalism, for we have seen that the agar on which mixed 

 cultures are planted sometimes remains free of bacterial colonies. 



TABLE 1 



January 15 



February 1 



February 15 . . . 



March 1 



March 15 



April 1 



April 15 



May 1 



May 15 



June 1 



June 15 



July 1 



July 15 



August 1 



August 15 



September 1 . . . 

 September 15 . . 



October 1 



October 15 



November 1 . . . 

 November 15 . . 

 December 1... . 

 December 15. . . 



Other organisms 



Salmonella-r-+4- 



B. enteritidis+ + 



However this may be, the table here given shows the results 

 of the tests made on the normal man in question. The examina- 

 tions are adequate to show that the bacteriophage is a normal 

 inhabitant of the intestine (table 1). 



During the course of this same year this individual showed at 

 two different times, July 3, and September 26, slight intestinal 



