PLATE 5. 



SOURCES OF COXTAM I NATION IX MILK. 



I. Air of byre.— 30 minutps' exposure during milking time Agar plate. Incubation, 24 hours at 

 37' C. ; 48 hours at 1S° C. Size of plate, 13 x 11 inches. 

 II. Air of dairy.— (i hours' exposure, inclu'ling 2 working hours. Agar plate. Incubation, 24 

 hours at 37' C. ; 48 hours at 18' C. Size of plate, 13 x 11 inches. 



[Face page 24. 



