PSEUDOMONAS PYOCYANEUS 75 



EXERCISE XXVI 



PSEUDOMONAS PYOCYANEUS 



111. Pseudomonas pyocyaneus, commonly known as the 

 bacillus of green pus, blue pus, or blue-green pus, is quite 

 widely distributed in nature. While ordinarily it has been 

 considered of little pathogenic importance, it is known to pos- 

 sess at times, and under certain conditions, marked infecting 

 powers. This organism has been called the honey bacillus, 

 on account of the peculiar odor emitted from its cultures. It 

 is to be differentiated from Ps. fluorescens liquefaciens and its 

 varieties which frequently appear in water. 



REFERENCES. Chapters on this organism in text-books. 

 Barker, The clinical symptoms, etc., The Jour, of the Am. Med. 

 Asso., July 31, 1897. Lartigau, Study of pathogenesis, Jour, of 

 Exp. Med., 1898, p. 595. Jordan, Pigments produced by, Ibid., 

 1899, p. 627. Ruzicka, Arch, fur Hygiene, Bd. XXXIV, S. 149, 

 andBd. XXXVII, S. I. 



112. Work for this exercise. Examine very carefully and 

 describe fully the cultures of Ps. pyocyaneus made during the 

 last exercise. 



Make and examine a hanging-drop and a stained cover- 

 glass preparation from each of the bouillon and agar cultures. 



Describe the appearance of the bacteria in each. 



Measure and make a drawing of a few organisms in the 

 preparation from the agar culture. Magnify 500 diameters. 



Reexamine the cultures of the streptococcus and the micro- 

 coccus studied in the last exercise and note all appreciable 

 changes which have taken place. 



Inoculate a tube of each of the media in Groups A and D 

 from a culture of B. coli communis (furnished) for study at 

 the next exercise. 



