318 ANTHRAX 



of the blood in cases of anthrax in man usually gives negative 

 results, with the exception of very severe cases, when a few 

 bacilli may be found in the blood shortly before death, though 

 even then they may be absent. 



(b) Cultivation. A small quantity of the material used for 

 microscopic examination should be taken on a platinum needle, 

 and successive strokes made on agar tubes, which are then 

 incubated at 37 C. At the end of twenty-four hours anthrax 

 colonies will appear, and can be readily recognised from their 

 wavy margins by means of a hand lens. They should also be 

 examined microscopically by means of film preparations. 



(c) Test Inoculations. A little of the suspected material 

 should be mixed with some sterile bouillon or water, and 

 injected subcutaneously into a guinea-pig or mouse, or it may 

 be introduced into the subcutaneous tissue by means of a seton. 

 If anthrax bacilli are present, the animal usually dies within 

 two days, with the changes in internal organs already described. 



