THE CULTIVATION OF MICRO-ORGANISMS IOy 



temperature anywhere between 28 and 40 C. Take a small 

 portion of the material to be examined pus, for example and- 

 introduce it with a sterilized platinum wire or loop into one of 

 the tubes. The plug of the test-tube is to be withdrawn, twisting 

 it slightly, taking it between the third and fourth fingers of the 

 left hand, with the part that projects into the tube pointing to- 

 ward the back of the hand. It must not be allowed to touch 

 any object while the inoculation is going on. Pass the neck of 

 the tube through the flame. If any of the cotton adheres to the 

 neck of the tube, pull the cotton away with sterilized forceps, 

 while the neck of the tube touches the flame, so that the threads 

 of cotton may be burned and not fly into the air of the room. 



FIG. 39. Method of inoculating culture media. 



The tube is held as nearly horizontal as possible. The tube is 

 to be held in the left hand between the thumb and forefinger, 

 the tube resting upon the palm, and the neck of the tube pointing 

 upward and to the right. Mix the material introduced thor- 

 oughly with the liquefied culture-medium, taking care not to wet 

 the plug. Now remove the plug again, and, having sterilized the 

 platinum wire, insert it into the liquefied medium. Carry three 

 loopfuls in sucession from thistube/whichisNo. i, into tube No. 2. 

 When two tubes are being used at the same time, they are 

 placed side by side between the thumb and forefinger of the left 

 hand. The two plugs are held between the second and third and 

 the third and fourth fingers of the left hand, respectively. The 

 wire may now be passed into the first tube, which we will suppose 



