162 PATHOGENIC BACTERIA. 



in which Marmorek's serum was used terminated fatally 

 after rather distinct improvement. 



It would seem as if an antiphlogistic serum would 

 occupy an important place in the future of medicine. 



In some cases the pus evacuated from wounds exhibits 

 a peculiar bluish or greenish color, from the presence of 

 the Bacillus pyocyaneus (Figs. 50, 51). This is a short, 

 delicate bacillus of small size, frequently united in chains 

 of four or six. It has round ends, is actively motile, does 

 not form spores, and can exist with or without oxygen. 



The superficial colonies upon gelatin plates form small, 

 irregular, ill-defined collections, which produce a fluores- 

 cence of the neighboring 

 gelatin. The gelatin soft- 

 ens gradually, and about 

 five days elapse before 

 liquefaction is complete. 



The microscope shows 

 the colonies to be round, 

 coarsely-granulated masses 



FIG. 51. Bacillus pyocyaneus: colonies upon gelatin (Abbott). 



with notched or filamentous borders. They have a yel- 

 low-green color. Upon the surface they form a delicate 

 clump with a smooth surface, finely granular, distinctly 

 green in the middle and pale at the edges. The colonies 

 sink into the gelatin as the liquefaction progresses. 



In gelatin puncture-cultures most of the development 

 occurs at the upper part of the tube, where a deep saucer 

 of liquefaction forms. The growth slowly descends into 

 the medium, and is the point of origin of a beautiful 

 fluorescence. The bacterial growth sinks to the bottom 

 as it ages. At times a delicate mycoderma forms on the 

 surface. 



Upon agar-agar the growth is at first bright green, 



