ROUTINE STUDY OF VARIOUS GROUPS 55 



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- 



FlG. 26 



Thermostat or Incubator 



old broth-culture of each bacterium, unless otherwise 

 directed. These plates are to be described once after 

 24-48 hours. (See Chap. X.) 



Note. — The thermostat or incubator (Fig. ?6) is a box 

 made of copper and having double walls, between which water 



