BACTERIOLOGICAL TECHNIC 51 



be incubated at 37" for 24 hours, unless otherwise in- 

 structed. 



2. At the end of 24 hours make from each agar tube: 



a) A physical description of the culture (see Section 



9). 



b) A hanging-drop examination. 



c) A Gram stained preparation. 



d) An ordinary stained preparation. 



All stained preparations and all Gram stains should 

 be preserved. 



3. Transfer from agar culture to the following 

 media: 



Dextrose agar. 

 Gelatin. 

 Potato. 

 Broth. 



Litmus milk. 



Dunham's solution, if a test for indol is to be 

 made. 

 These transfers, excepting gelatin, are to be placed 

 in the thermostat, unless otherwise ordered. 



4. An accurate description and sketches are to be 

 made of each culture (see Section 9). These descrip- 

 tions should be made complete after 24 hours, and any 

 changes should be noted after 48 hours and after 6 

 days. (See culture charts.) 



5. Plates are to be made in agar from a 24-48-hour- 

 old broth culture of each culture, unless otherwise 

 directed. These plates are to be described once after 

 24-48 hours. (See Section 9.) 



Note. — ^The thermostat or incubator (Fig. 20) is a box 

 made of copper and having double walls, between which water 



