290 BACTERIOLOGY. 



behavior of the other pyogenic cocci when treated in 

 the same way ?) 



It does not grow upon ordinary nutrient media, 

 and has only been isolated in culture through the em- 

 ployment of special methods. Its growth under arti- 

 ficial conditions seems to depend upon some partic- 

 ular nutrient substance that is supplied by blood or 

 blood-serum, and in all the media that have been suc- 

 cessfully used for its cultivation this substance is 

 apparently an essential constituent. By many investi- 

 gators it is thought that only human blood possesses 

 this important ingredient, though this opinion is not 

 universal.^ 



It was first isolated in culture by Bumm, Avho used 

 for this purpose coagulated human blood-serum ob- 

 tained from the placenta. 



Wertheim improved the method of Bumm by using 

 a mixture of equal parts of sterile human blood-serum 

 and ordinary sterilized nutrient agar-agar, the latter 

 having been liquefied and kept at 50° C. until after 

 the mixture was made, when it was allowed to cool and 

 solidify. 



Other investigators have substituted for human blood- 

 serum certain pathological fluids from the human body, 

 such as ascites-fluid, fluid from ovarian cysts, and serous 

 efi^usions from the pleura and from the joint-cavities. 



The method used by Pfeiifer for the cultivation of 

 the bacillus of influenza is also said to have been suc- 

 cessfully employed. Abel recommends a needle-prick 

 in the finger as a most convenient source from which to 



' An instructive article on this subject is tliat by Foulerton: "On 

 Micrococcus Gonorrhcefe and Gonorrhoea! Infection," Transactions of 

 the British Institute of Preventive Medicine, 1897, series i. 



