BACILLUS PYOCYANEUS. 269 



may last from ten minutes to half an hour. This is 

 the " chameleon phenomenon" of Paul Ernst. 



In bouillon the green color appears, and the growth 

 is seen in the form of delicate flocculi. A very deli- 

 cate mycoderma is also produced. 



In milk it causes an acid reaction, with coincident 

 coagulation of the casein. 



On blood-serum and egg-albumin its growth is ac- 

 companied by liquefaction. The growth on coagulated 

 egg-albumin is seen as a dirty-gray deposit surrounded 

 by a narrow brownish zone; the remaining portion of 

 the medium is bright green in color. As the culture 

 becomes older the green may give way to a brown dis- 

 coloration. 



In peptone solution (double strength) it causes a 

 bluish-green color. In one of four cultures from differ- 

 ent sources there was a distinct blue color produced. 



It produces indol. 



It stains with the ordinary dyes, and its flagella may 

 be readily demonstrated by Loeffler^s method of staining. 



Inoculation into animals. As a rule, cultures of this 

 organism obtained directly from the discharges of a 

 wound are capable, when introduced into animals, of 

 lighting up diseased conditions; but cultures that are 

 kept on artificial media for a long time may in part, or 

 completely, lose this power. 



When guinea-pigs or rabbits are inoculated subcuta- 

 neously with 1 c.c. of virulent fluid cultures of this 

 organism, death usually results in from eighteen to 

 thirty-six hours. At the seat of inoculation there is 

 found an extensive purulent infiltration of the tissues 

 and a marked zone of inflammatory oedema. 



When introduced directly into the peritoneal cavity 



