596 APPLICATION OF METHODS OF BACTERIOLOGY 



Do the anthrax threads, as seen in a fresh, growing, 

 hanging drop, present the same morphological appearance 

 as when dried and stained upon a cover-slip? How do they 

 differ? 



Liquefy a tube of agar-agar, and when it is at the tem- 

 perature of 40 to 43 C. add a very minute quantity of an 

 anthrax culture which is far advanced in the spore-stage. 

 Mix it thoroughly with the liquid agar-agar and from this 

 prepare several hanging drops under strict antiseptic pre- 

 cautions, using the fluid agar-agar for the drops instead 

 of bouillon or salt solution. Select from among these 

 preparations that one in which the smallest number of 

 spores are present. Under the microscope observe the 

 development of a spore into a mature cell. Describe care- 

 fully the developmental stages. 



Prepare a 1 : 1000 solution of carbolic acid in bouillon. 

 Inoculate this with virulent anthrax spores. If no develop- 

 ment occurs after two or three days at the temperature of 

 the thermostat, prepare a solution of 1 : 1200, and continue 

 until the point is reached at which the amount of carbolic 

 acid present jwt permits of the development of the spores. 

 When the proper dilution is reached prepare a dozen of 

 such tubes and inoculate one of them with virulent anthrax 

 spores. As soon as development is well advanced transfer 

 a loopful from this tube into a second of the carbolic acid 

 tubes; when this has developed, then from this into a third, 

 etc. After five or six generations have been treated in this 

 way study the spore production of the organisms in that 

 tube. If it is normal, continue to inoculate from one car- 

 bolic acid tube to another, and see if it is possible by this 



