278 BACTERIOLOGY. 



then sealed in the flame and the material can thus be pre- 

 served for future use. At times, there is very little exudate 

 although the bacteria may be present in abundance. In 

 that case, if it is desired to inoculate direct into another 

 animal, some bouillon should be transferred by means of 

 a drawn-out pipette to the abdominal cavity. By rubbing- 

 the pipette over the surface of the peritoneum and drawing 

 up the liquid into the pipette, several times in succession, 

 a good bacterial suspension can be obtained. One of the 

 best methods of increasing the virulence of an organism is 

 by successive passage through animals. 



With sterile forceps and scissors, the spleen, liver and 

 kidneys can be transferred to sterile Esmarch dishes and 

 subsequently examined. Pieces of these organs can be 

 hardened and sectioned (Chapter XV). 



Fig. 49. a— The Roux spatula of nickeled steel; *— Nuttall's platinum needle. 



If it is desired to make transplantations from any of 

 these organs, the surface should first be seared with a hot 

 knife or with the searing iron (Fig. 48 a). Portions of the 

 organ can then be cut out with sterile instruments and 

 transferred to tubes. The sterile pipette can also be used 

 for removing a portion of the pulp to the culture media. 

 The spatula employed by Roux to remove diphtheritic 

 membranes is well adapted to pick up pieces of tissues. 

 These can then be thoroughly smeared over the surface of 

 the medium, or squeezed against the walls of the tube. 

 Nuttall's' platinum needle (Pig. 49 b) is likewise very use- 

 ful in transferring bits of tissue to the culture tube. 



The heart-blood, as a rule, contains the specific organ- 

 ism in the purest condition. A large amount of blood can be 

 drawn from the heart, especially if this is done immediately 



