ILLUSTRATIONS XI 



PAGE 



Worthless Camembert. Showing Pores Produced by Gas- 

 forming Bacteria 252 



Penicillin m roqiicforti 254 



Test Tubes Board of Health Pattern 264 



Pipette and Glass Tube for Holding Same when Sterilized 266 



Hot Air Sterilizer 266 



Steam Sterilizer 269 



Filtering Culture Media 270 



Filling Test Tubes with a Measured Amount of a Culture 



Medium 271 



Hardening Agar Slants 273 



Vials for Milk Dilution 274 



Autoclav for Sterilizing under Steam Pressure .... 275 



Peri Dish 276 



Counting-box 277 



Platinum Needles 282 



Forceps for Holding Cover-glasses 283 



Centrifuge for Milk Testing 285 



Making Gelatin Stabs 290 



Cutter for Making Potato Plugs, Method of Cutting Them 



and Placing in Tubes 293 



Types of Gelatin Stab Growths 294 



Types of Gelatin Liquefaction 294 



Types of Surface Elevation 296 



