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Now carefully remove the wire without touching the 

 microscope or some other portion of the gelatin. A tube 

 of solid gelatin is held in the left hand in an almost hori- 

 zontal position, the plug is then removed by grasping it 

 with the little finger of the right hand, and the platinum 

 wire, which has a small portion of the colony attached to 

 it, is slowly forced down the centre of the gelatin to the 

 bottom of the tube. The cotton plug is at once replaced, 

 the wire sterilized and the tube set aside. 



The stich culture thus made is a pure culture and is 

 now labelled with the name of the organism and date and 

 set aside to develop. In a few days development takes 

 place along the line of inoculation and more or less char- 

 acteristic growth results. 



The manner of growth should be daily observed. 

 Hanging-drop and stained preparations can, of course, be 

 made if desired, from tube cultures. When the gelatin 

 is very old, and hence too solid, it tends to split as soon as 

 the platinum wire is forced into it. This is remedied by 

 melting the gelatin and allowing it to re-solidify. 



LABORATORY WORK. Examine carefully the colonies 

 with the eye and under the microscope. Make hanging- 

 drop and stained preparations from the colonies. Prac- 

 tice "fishing" and make stich cultures from each of the- 

 different colonies. 



The line of study of the Micrococcus prodigiosus and 

 Bacillus Indicus and of the various bacteria to be pres- 

 ently taken up, consists first, in making plate cultures. 

 Colonies are thus obtained, the characteristics of which 

 are to be thoroughly studied. Hanging-drop examination! 

 and stained preparation are next made, thus becoming; 

 familiar with the organism itself. Stich cultures in gela 

 tin are then made and also streak cultures on potato or 

 agar which will be presently described. Finally drawings 

 should be made showing the form of the colony, the form 

 of the organism, the appearance of the stich culture, etc. 



4 



