548 PATHOGENIC MICROORGANISMS 



and others to take place in the free secretions, not in the depth of the 

 tissues. The intracellular position, which is of considerable diagnostic 

 importance, is lost to a great extent in secretions from chronic cases. 

 In smears made from pure cultures the arrangement in groups of two 

 may often be less marked than in pus, clusters of eight or more being 

 common. 



The gonococcus is non-motile and does not form spores. It is easily 

 stained with aqueous anilin dyes. Methylene-blue alone, or eosin 

 followed by methylene-blue, give good results. An excellent picture 

 is obtained with the Pappenheim-Saathof stain consisting of 



Methyl green 0.15 



Pyronin 0. 5 



96 per cent alcohol 5. 



Glycerin 20. 



2 per cent carbolic acid water ad 100. 



Fix; stain 1-2 min. 



Gram's method of staining, however, is the only one of differential 

 value, gonococcus being Gram negative. The Gram stain applied to 

 pus from the male urethra, while not absolutely reliable, is, for practical 

 purposes, sufficiently so to make a diagnosis. In exudates from the 

 vagina or from the eye the morphological picture is not so reliable, 



owing to the frequent presence in 

 these regions of other Gram-negative 

 cocci. The great scarcity of gono- 

 cocci in very chronic discharges 

 necessitates thorough cultural investi- 

 gation ; negative morphological exami- 

 nation in such cases can not be 

 regarded as conclusive. 4 



Cultivation. The gonococcus is 

 delicate and difficult to cultivate. 

 Bumm 5 obtained his first growths 



58.-GoNococcus. Smear u P on human blood serum which 

 from pure culture. had been heated to partial coagu- 



lation. 



The medium most commonly used at the present day was intro- 

 duced by Wertheim, 6 and consists of a mixture of two or three parts of 



4 Heiman, Medical Record, 1896. 



5 Bumm, Dent. med. Woch., 1885. 



6 Wertheim, Arch. f. Gynakol., 1892. 





t. 



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