EXERCISE XXIV. 



CLEANING USED CULTURE TUBES, FLASKS, AND PETRI 



DISHES. 



87. General directions. Describe the bouillon cul- 

 tures made from the colonies on the agar plates Exercise 

 XXIII. Describe the bacteria in the stained cover-glass 

 preparations and compare them with the bacteria in the 

 preparations made from the colonies. 



Reject and clean all tubes and Petri dishes that have been 

 used for cultures. 



Complete the notes on all work which has been done dur- 

 ing the fall term. 



Have all apparatus for individual use inspected by the in- 

 structor and released. 



EXERCISE XXV. 



PREPARATION OF GLASSWARE FOR CULTURE MEDIA. 



88. Explanatory note. It is desirable that the tech- 

 nique in plugging and sterilizing test tubes and flasks and in 

 making culture media should be thoroughly understood. On 

 this account this part of the work of the fall term is repeated, 

 but hereafter in the course, the janitor will clean all glass- 

 ware and the instructor will furnish all additional media re- 

 quired. It will be necessary in the following exercises to 

 overlap to a considerable extent by way of inoculating media 

 and in making the final examinations of cultures. 



89. General directions. Plug and sterilize the test 

 tubes and flasks and sterilize the Petri dishes. 



