PSEUDOMONAS ^RUGINOSA. 309 



needle toward the median line, rather than to make 

 lateral movements, with the danger of breaking the 

 needle or causing a hemorrhage. The smallest quantity 

 of blood obscures the macroscopic appearance of the 

 fluid by rendering it cloudy. The fluid is allowed to 

 drop into an absolutely clean test-tube, which previously 

 has been sterilized by dry heat to 150 C. and stop- 

 pered with cotton. The fluid should be allowed to 

 drop into the tube without running down the sides. 

 From 5 to 15 c.c. of fluid is a sufficient quantity for 

 examination." 1 



PSEUDOMONAS ^ERUGINOSA (SCHROTER, 1872), 

 MIGULA, 1900. 



Synonyms : Bacterium eeraginosum, Schroter, 1872 ; Bacillus seru- 

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

 inouas pyocyanea, Migula, 1896. 



Another common organism that may properly be 

 mentioned at this place, though perhaps not strictly 

 pyogenic, is a pseudomonas frequently found in dis- 

 charges from wounds, viz., pseudomonas ceruginosa, or 

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

 pus, as it is variously designated. Pseudomonas ceru- 

 ginosa 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 clus- 

 tered in irregular masses. It does not form long fila- 

 ments, 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 



1 For a comprehensive treatment of this subject from its etiological 

 and pathological standpoints, see the monograph of Councilman, Mai- 

 lory, and Wright, to which reference was made above, and to which 

 we are indebted for much contained in the foregoing sketch. 



