FILLING THE TUBES. \\\ 



may be allowed to flow into the tubes held under its 

 opening. 



It is not necessary to sterilize the funnel, for the 

 medium is to be subjected to this process as soon as it 

 is in the test-tubes. 



FIG. 22. 



Funnel for filling tubes with culture media. 



Care should be taken that none of the medium is 

 dropped upon the mouth of the test-tube, otherwise the 

 cotton plug becomes adherent to it, and is not only 

 difficult to remove, but presents a very untidy appear- 

 ance, and interferes, indeed, with the proper manipula- 

 tions. 



As soon as the tubes have been filled they are to be 



