ISOLATION OF THE BACILLUS 



423 



\ 



Fig. 121. — Spiral composed of numerous twisted 



flagella of the tetanus bacillus. 



. Stained by Ed. Muir's method, x 1000. 



bacilli, both in its natural habitats outside the body and in the 

 pus of wounds, other 

 spore - forming obliga- 

 tory and facultative 

 anaerobes occur, which 

 grow faster than the 

 tetanus bacillus, and 

 thus overgrow it. 



(2) If in any dis- 

 charge the spore-bearing 

 tetanus bacilli be seen 

 on microscopic examina- 

 tion, then a method of 

 isolation based on the 

 same principle as the 

 last may be adopted. 

 Inoculations with differ- ' 

 ent dilutions of the sus- 

 pected material are 

 made in half a dozen 

 deep tubes of glucose- 



bouillon, previously raised to a temperature of 100° C. After 



inoculation they are 



^" again placed in boiling 



/ x water and kept for 



/ jj varying ' times, say for 



/ i half a minute, for one, 



/ ^5 -"*- N three, four, five, and 



/ , six minutes respectively. 



They are then plunged 

 in cold water till cool, 

 and thereafter placed in 

 the incubator at 37° C, 

 f / in the hope that in one 



or other of the tubes 

 / all the organisms 



present will have been 

 killed, except the 

 tetanus spores which 

 can develop in pure 

 culture. A series 

 of deep glucose agar 

 tubes may also be in- 

 tubes. 



N 



A 



Fig. 122.— Tetanus bacilli; some of which 

 possess spores. From a culture in glucose 

 agar, incubated for three days at 37° C. See 

 also Plate IV., Fig. 20. 



Stained with carbol-fuchsin. x 1000. 



oculated from the series of bouillon 



