22 



First, sterilize six glass plates by placing them in an 

 iron box and heating this in the dry heat sterilizer, at a 

 temperature of 150-175 0., for one hour. Then remove the 

 box and allow it to cool. 



PJace three of the sterilized gelatin tubes in a water- 

 bath which has been warmed to about 30-35 0. When 

 the gelatin melts the tubes are ready for inoculation. 

 With a sterilized, cooled platinum wire pick up a minute 

 amount of the growth of the potato culture of Micrococcus 

 prodigiosus. Place one of the liquefied gelatin tubes 

 between the thumb and index finger of the left hand, so 

 that it is almost horizontal. The neck of the tube with 

 its plug, as well as the palm of the left hand, is turned to 

 the right. While still holding the platinum wire in the 

 right hand, grasp the cotton plug with the little finger of 

 that hand, and remove it by slight rotation. Now pass 

 the inoculated wire into the tube and thoroughly mix the 

 bacteria, thus introduced, with the gelatin. Then with- 

 draw the wire, replace the cotton plug, and sterilize the 

 platinum wire in a flame. 



With a colored wax pencil mark the tube thus inocu- 

 lated with J. Likewise mark another liquefied gelatin 

 tube with 2. Place tube 1 in the left hand in the same 

 position as before, and then next to it, tube 2. Remove 

 the cotton plug of tube 2 and place it between the adjoin- 

 ing index and middle fingers. Then remove the cotton 

 plug of tube 1 and place it between the ring and little 

 finger. Now, with a sterilized cooled platinum wire, the 

 end of which is provided with a small loop, transfer a 

 loopful of gelatin from tube 1 to tube 2 and mix well. 

 Return the platinum wire to tube 1 and again transfer a 

 loopful of gelatin to tube 2. Repeat this once more, so 

 that all told, three transfers of inoculated gelatin have 

 been made. Replace the cotton plugs into their respect- 

 ive tubes, sterilize the platinum wire and set the tubes in 

 a tumbler having a layer of cotton on the bottom. 



Mark a new liquefied gelatin tube with 3. Then place 

 2 in the same position in which No. 1 was just held, and 



