386 BACTERIOLOGY. 



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 which 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 carbolic acid tube into another, and see if it is possi- 

 ble by this means to influence in any way the production 

 of spores by the organism with which you are working. 

 What is the effect, if any? 



Prepare two bouillon cultures, each from one drop of 

 blood of an animal dead of anthrax. (Why from the blood 

 of an animal and not from a culture ?) Allow one of them 

 to grow for from fourteen to eighteen hours in the incu- 

 bator ; allow the other to grow at the same temperature 

 for three or four days. Remove the first after the time 

 mentioned and subject it to a temperature of 80 C. for 

 thirty minutes. At the end of this time prepare four 

 plates from it. Make each plate with one drop from 

 the heated bouillon culture. At the end of three or four 

 days treat the second tube in identically the same way. 

 How do the number of colonies which developed from 

 the two different cultures compare? Was there any 

 difference in the time required for their development 

 on the plates? 



From a potato culture of anthrax bacilli which has 

 been in the incubator for three or four days, scrape 

 away the growth and carefully break it up in 10 c.c. of 

 sterilized physiological salt solution. The more carefully 

 it is broken up the more accurate will be the experiment. 

 Place this in a bath of boiling water and at the end of 

 one, three, five, seven, and ten minutes make a plate 



