ISOLATION OF THE BACILLUS 



375 



pares the colonies in gelatin plates to those of the b. subtilis. 

 They consist of a thick 

 centre with shoots radi- 

 ating out on all sides. 

 They liquefy the gelatin 

 more slowly than the b. 

 subtilis. This method 

 of isolation is not always 

 successful, partly because 

 along with the tetanus 

 bacilli, both in its 

 natural habitats outside 

 the body and in the pus 

 of wounds, other spore- 

 forming obligatory and 

 facultative anaerobes oc- 

 cur, which grow faster 

 than the tetanus bacillus, 

 and 'thus overgrow it. 



(2) If in any dis- 

 charge the spore-bearing 

 tetanus bacilli be seen 



1 



JfP 



. 



FIG. 126. Spiral composed of numerous 



twisted flagella of the tetanus bacillus. 

 Stained by Kd. Muir's method. x 1000. 



\ 



^ 



on microscopic examination, then a 

 method of isolation 

 based on the same prin- 

 ciple as the last may 

 be adopted. Inocula- 

 tions with the suspected 

 material are made in 

 half a dozen deep tubes 

 of glucose agar, previ- 

 ously melteTand kept at 

 a temperature of 100 

 C. After inoculation 

 they are again placed in 

 boiling water and kept 

 for varying times, say 

 for half a minute, for 

 one, three, four, five, 

 and six minutes respect- 

 ively. They are then 

 plunged in cold water 

 till cool, and thereafter 

 placed in the incubator at 37 C., in the hope that in one 

 or other of the tubes all the organisms present will have been 



FIG. 127. Tetanus bacilli ; some of which 

 possess spores. From a culture in glucose 

 agar, incubated for three days at 37 C. 

 Stained with carbol-fuchsin. x 1000. 



