388 Tetanus 



Park,* following the suggestion of Kitasato, covers the 

 surface of the bouillon with a layer of paraffin about i to 2 cm. 

 thick. This melts in the sterilization and forms a firm layer, 

 through which the bouillon is inoculated, warmed until 

 the paraffin melts again, then stood away until develop- 

 ment in the air-free bouillon occurs. If the paraffin be 

 found too brittle, some albalene may be mixed with it until 

 it is flexible when cool. 



The colonies of the tetanus bacillus, when grown upon 

 gelatin plates in an atmosphere of hydrogen, resemble those 



Fig. 120. Bacillus tetani; five-day-old colony upon gelatin-containing 

 glucose. X 1000 (Frankel and Pfeiffer). 



of the well-known hay bacillus. There is a rather dense, 

 opaque central mass surrounded by a more transparent 

 zone, the margins of which consist of a fringe of radially 

 projecting bacilli. Liquefaction occurs slowly. 



Bouillon. The organism can be grown in bouillon, and 

 attains its maximum development at a temperature of 

 37 C. Gas is given off from the cultures, and they have a 

 peculiar odor, very characteristic, but difficult to describe, 

 The bouillon is clouded and contains a sediment. 



* "Jour. Med. Research," N. S., vol. i, No. i, p. 298. 



