BACILLUS PYOCYANEUS 581 



Bulloch and Hunter ' have recently been able to show that old 

 broth cultures of B. pyocyaneus contain a substance capable of 

 hemolyzing the red blood corpuscles of dogs, rabbits, and sheep. 

 This "pyocyanolysin" seems intimately attached to the bacterial 

 body. Prolonged heating of cultures does not destroy it. Heating of 

 hemolytic filtrates, however, destroys it in a short time. The filtration 

 of young cultures yields very little pyocyanolysin in the filtrate. In 

 old cultures, however, a considerable amount passes into the filtrate. 

 Whether or not the hemolytic pow^r is due to a specific bacterial 

 product or is dependent upon changes in the culture fluid, such as 

 alkalinization, etc., can not yet be regarded as certain. 



Gheorghiewski ' claims to have found a leucocyte-destroying ferment 

 in pyocyaneus cultures. 



' Bulloch und Hunter, Cent. f. Bakt., xxviii, 1900. 

 * Gheorghiewski, Ann. de I'inst. Pasteur, xiii, 1899. 



