PSEUDOMONAS ^RUGINOSA 363 



the rates ran from 20 to 25 per cent. For success, therefore, 

 early diagnosis and early administrations of the serum are 

 essential. 



PSEUDOMONAS ^RUGINOSA (SCHROTER, 1872), 

 MIGULA, 1900. 



Synonyms: Bacterium jEruginosum, Schroter, 1872; Bacillus jEru- 

 ginosus, Schroter, 1872; Bacillus Pyocyaneus, Gessard, 1882; Pseudo- 

 monas Pyocyanea, Migula, 1896. 



Another common organism that may properly be men- 

 tioned at this place, though perhaps not strictly pyogenic, 

 is a pseudomonas frequently found in discharges from 

 wounds, viz., pseudomonas aeruginosa, or bacillus pyocyaneus 

 or "bacillus of green pus," or of blue pus, or of blue-green 

 pus, as it is by custom variously designated. Pseudomonas 

 aeruginosa is a delicate rod with rounded or pointed ends. 

 It is actively motile; does not form spores. As seen in 

 preparations made from cultures, it is commonly clustered 

 in irregular masses. It does not form long filaments, there 

 being rarely more than four joined end to end, and most 

 frequently occurs as single cells. 



It grows readily on all artificial media, and gives to some 

 of them a bright-green color that is most conspicuous where 

 it is in contact with the air. This green color, which becomes 

 more and more marked as growth advances, is not seen in 

 the growth itself to any extent, but is diffused through the 

 medium on which the organism is developing. Ultimately 

 this color becomes much darker, and in very old cultures 

 may become almost black (sometimes very dark blue-green, 

 at others brownish-black, at others more or less of a claret 

 red). 



