ANTHRAX 



6l 



The other culture is made by blowing a drop or two of the 

 fluid into a tube of gelatin melted at the body temperature. The 

 two are to be thoroughly mixed together and then poured into 



Fig. ig, — Petri's Dish. 



a Petri dish (Fig. 19), previously sterilized by dry heat and 

 allowed to cool. 



Both cultures are incubated at a temperature of about 20° C. 

 In about two days the gelatin stab-tube will show a very 

 characteristic appearance if the anthrax bacilli 

 are present in pure culture. The growth 

 takes place in lines which project nearly 

 at right angles to the line of inoculation, 



^« 



Fig. 21. 



-Young Colony of Anthrax Bacillus 

 ( X 15). (Crookshank.) 



Fig. 20. — Stab Cul- 

 ture OF Anthrax 



Bacillus. 



SHANK.) 



(Crook- 



and grow more vigorously the nearer they 

 are to the surface. The result is the de- 

 velopment of a culture which has a strong 

 resemblance to an inverted fir-tree (Fig. 20). 

 In another day or two the gelatin will begin 

 certain amount of liquefaction, which begins at the 



to show a 

 surface. 



The appearances in the plate culture are perhaps not quite so 

 characteristic, but they are manifested in impure cultures. The 



