CULTIVATION OF THE BACILLUS 8S 



Holth inoculated the following media, on which he 

 obtained good growths : 



(a) Blood-serum (horse) with 4 per cent, glycerine 

 and 2 per cent, dead tubercle bacilli added. The 

 bacilli were obtained from a two months' old broth 

 culture, and, before being added to the medium, were 

 mixed with a small quantity of salt solution and heated 

 to 100° C. for one and a half hours. The bacilli were of 

 the human type. 



{b) Blood -serum with a quarter volume of liver 

 broth, 2 per cent, dead tubercle bacilli, and 4 per cent, 

 glycerine. 



{c) Serum agar with 2 per cent, dead tubercle bacilli 

 and I per cent, glycerine. 



{d) Egg medium as used by ourselves. 



The tubes were sealed with paraffin and placed at 

 37° C, and in six weeks multiplication of the bacilli 

 was found to have taken place. 



Holth found that the best growth occurred on {b). 

 At the end of six weeks the whole surface of the 

 medium was covered with colonies visible to the naked 

 eye and varying in size from J to i millimetre. Sub- 

 cultures on to other similar media showed good growth 

 after four weeks. To avoid the presence of tubercle 

 bacilli in the medium, a glycerine extract was prepared. 

 The bacilli from the growth on about 200 c.c. of a two 

 months' broth culture were mixed with about 40 c.c. 

 of glycerine, and, after shaking, the mixture was heated 

 for an hour at 100° C. After standing at room tem- 

 perature for several days, the pale yellowish-brown 

 liquor was decanted. The addition of 5 per cent, of 

 this liquid to the media in place of the tubercle bacilli 

 was found to give good results. 



Holth states in his paper that the bacilli cultivated 

 agreed in their morphology and staining reactions with 



