THE INFECTIOUS DISEASES. 217 



Characters of the Gonococcus. 



The gonococcus is apt to occur in pairs, the apposed sides being more or less dis- 

 tinctly flattened (Fig. 102). It stains readily with the anilin dyes, and differs from most 

 known cocci which might be mistaken for it in that it is decolorized by the iodin solu 

 tion in the Gram method of staining. It is well after the decolorization by this 

 method, and before mounting in balsam, to make a contrast stain with a dilute aqueous 

 solution of Bismarck brown. Then the gonococci will be of light-brown color, while 

 most other germs will retain the violet color. 



The gonococcus does not grow at ordinary room temperatures nor on the ordinary 

 solid or fluid culture media. It may, however, be cultivated at the temperature of the 

 body on human blood serum or on a combination of this with agar. Heiman has found 

 that it grows readily on the clear exudate or transudate 



from the pleural cavities in man when this is mixed ^ * % * \ 



with peptonized agar. ' * 



In this "chest-serum agar" the surface growth of * , _ 



the gonococcus is in the form of small circular, sharp- ' i * % ' *^ 



edged, slightly raised, nearly transparent colonies, ** 



coarsely mottled in the central portion, finely granular 



toward* the borders. The life of the colonies under arti- FIG. 102.-MicRococcrs GOXOR- 

 ficial culture is short, but by frequent transference to 



fresh media it may be maintained indefinitely and grad- From culture, 



ually adapts itself to the artificial environment. It is 



probable that the organism has no natural habitat outside the bodies of human beings. 

 The lower animals are not, as a rule, susceptible to inoculations of the mucous mem- 

 branes with the gonococcus, but suppurative inflammation has been induced in mice 

 and guinea-pigs by intraperitoneal injections. 



Inoculations of pure cultures of the gonococcus upon the urethral 

 mucous membranes of man have been repeatedly made and were fol- 

 lowed by a characteristic catarrhal inflammation. Thus the evidence is 

 complete that the gonococcus is an excitant of the inflammation with 

 which it is so constantly associated. But in what measure this germ, in 

 what measure others are responsible for the complicating inflammations 

 when both germs occur together, is yet to be determined. 



Inasmuch as one or more forms of cocci and diplococci occurring in 

 the normal and in the inflamed urethra are morphologically similar to 

 the gouococcus, great caution should be exercised in doubtful cases in 

 deciding upon the nature of suspicious micro-organisms in urethral dis- 

 charges or other exudates. But the pronounced tendency of the gono- 

 coccus to gather within cells ; the sometimes conspicuous but often ill- 

 defined flattening of the apposed sides of the gonococci ; the decolorization 

 by Gram's method, which leaves most other germs apt to be associated 

 with the gonococcus still stained, and whenever practicable" the artificial 

 culture characters these all should be considered in the summary of 

 evidence. * 



1 Heiman, Medical Record, June 22d, 1895, bibl. 



2 Von Hibler, Centralbl. f. Bakteriologie, etc., Bd. xix., p. 120, 1896. For sum- 

 mary of studies on the gonococcus with bibliography consult Jfeitser and W. Scholtz in 

 Kolle and Wassermann's "Handbuch der Mikroorgauismen,'' Bd. ii., p. 148. 



A comprehensive biblioeraphv may be found in an article by Elting, Albany 

 Medical Annals, March. 1900. 



