CHAPTER V. 



METHODS OF INOCULATION. 



HAVING now in test-tubes and small flasks sterile material 

 ready for inoculation, it is necessary to describe the mode of 

 inoculating the same. 



1. Inoculations from Artificial Cultures. The first and 

 simplest is the case where it is required to inoculate a new 

 tube or flask with a definite organism that has been growing 

 previously in a culture-tube ; that is to say, where it is 

 required to establish from an artificial cultivation a new and 

 further artificial cultivation. Take a freshly drawn-out 

 capillary pipette, with a fine point, as described in a former 

 chapter ; draw up with clean forceps slightly the top part of 

 the cotton- woo I plug of the old tube or flask, push carefully 

 and gently one of the pointed ends of the capillary pipette 

 the other can be broken off blunt through the remaining 

 part of the cotton- wool plug, and push it downwards till it 

 emerges into the culture-fluid, or, if this be solid material, till it 

 reaches the spot or place where the organism is growing ; allow a 

 small droplet to ascend into the capillary pipette, which it 

 readily does by capillarity ; or if a larger quantity is required 

 draw it up by gently sucking at the outer end of the capillary 

 pipette. Then draw the capillary pipette altogether out of the 

 tube and cotton- wool plug, and push this latter down with the 

 forceps into its former position. Immediately after this pro- 

 ceed to inoculate the new culture-tube by doing exactly the 

 same as before, viz., draw up slightly with the forceps the top 

 part of its cotton- wool plug, push through the remainder of 

 this plug the pointed end of the capillary pipette, i e. the one 

 containing the droplet of the material to be sown, and push 

 it into the material at the bottom of the test-tube or flask. A 

 trace of the sowing material flows out by itself, or, if a large 



