226 GONORRHCEA, SOFT SORE, SYPHILIS. 



purposes of culture. The organism does not grow on gelatin,^ 

 potato, etc. 



Plate-cultures. — The following ingenious method of plate-culture was 

 introduced by Wertheim for the culture of the gonococcus. The medium of 

 culture is a mixture of human blood serum and of ordinary agar (2 per cent) 

 in equal parts. The serum, in a fluid and sterile condition, is put in suitable 

 quantities into two or three test-tubes and brought to a temperature of 45° C. 

 These are then successively inoculated with the pus or other material in the 

 same manner as gelatin tubes for ordinary plates {vide p. 54) . To each tube 

 is added an equal part Of ordinary agar which has been thoroughly liquefied 

 by heating and allowed to cool also to 45° C. The mixture is then thoroughly 

 shaken up and quickly poured out on a plate or Petri's dish and allowed to 

 solidify, the plates being then incubated at a temperature of 37° C. The 

 colonies of the gonococcus are just visible in twenty-four hours, and are seen 

 both in the substance of the medium and on the surface. The deep colonies 

 when examined with a lens are minute and slightly nodulated spheres, some- 

 times showing little processes, whilst those on the surface are thin discs of 

 larger diameter with wavy margin and rather darker centre. In this way the 

 gonococcus may be separated from fluids which are contaminated with a con- 

 siderable number of other organisms. 



Relations to the Disease. — The gonococcus is invariably 

 present in the urethral discharge in gonorrhoea, and also in 

 other parts of the genital tract when these are the seat of true 

 gonorrhoeal infection. Its presence in these different positions 

 has been demonstrated not only by microscopic examination 

 but also by culture. From the description of the conditions of 

 growth in culture, it will be seen that a life outside the body 

 in natural conditions is practically impossible — a statement 

 which corresponds with the clinical fact that the disease is 

 always transmitted directly by contagion. Inoculations of pure 

 cultures on the urethra of lower animals, and even of apes, is 

 followed by no effect, but a similar statement can be made with 

 regard to inpculations of gonorrhoeal pus itself. In fact, hith- 

 erto it has been found impossible to reproduce the disease by 

 any means in the lower animals. On a considerable number of 

 occasions inoculations of pure cultures have been made on the 

 human urethra, both in the male and female, and the disease, 

 with all its characteristic symptoms, has resulted. (Such 



1 Turro has announced that he has cultivated the gonococcus on acid gelatin, 

 i.e. ordinary peptone gelatin which has not been neutralised. We have failed to ob- 

 tain any growth of the gonococcus on this medium, even when inoculation was made 

 from a vigorous growth on blood agar. 



