278 



THE BACILLUS OF BLUE PUS 



similar effect. In broth containing boric acid the bacillus assumes a spiral 

 form, and in media containing creosote it looks like a coccus (figs. 174 to 177). 



FIG. 174. Culture in 4 per cent, 

 alcohol broth. 



FIG. 175. Culture in 0'015 per cent, 

 potassium bichromate broth. 



FIG. 176. Culture in 0'70 per cent, 

 boric acid broth. 



FIG. 177. Culture in O'lO per cent. 

 creosote broth. 



FIGS. 174-177. Different morphological appearances presented by the Bacillus 

 pyocyaneus when grown in broth containing traces of antiseptics (after Guignard 

 and Charrin). 



2. Cultural characteristics. 



Conditions of growth. The bacillus pyocyaneus is a facultative aerobe but 

 the pigment is only formed in presence of air. It grows at all temperatures 

 between 15 and 43 C., the optimum temperature being about 35-37 C. 



FIG. 178. Bacillus 

 pyocyaneus broth cul- 

 ture 1st day. 



FIG. 179. Bacillus 

 pyocyaneus broth cul- 

 ture 3rd day. 



FIG. 180. Bacillus 

 pyocyaneus broth cul- 

 ture 7th day. 



Characters of growth on various media, (i) Broth. After incubating at 

 37 C. for 8 hours the medium becomes cloudy, and then a greenish 

 fluorescence appears at first limited to the upper part of the medium then 





