ACID-FAST BACILLI IN BUTTER AND MILK 363 



" granular " centre is surrounded by a light blue zone, but slightly 

 raised above the medium (see Plate) ; on glycerine potato, there is 

 at first a white creamy growth very little raised above the surface of 

 the medium, but as it grows older the culture becomes wrinkled ^and 

 of a deep yellowish tint, almost red. The bacillus grows quickly and 

 luxuriantly in milk, forming an ochre-yellow ring round the surface 

 edge of the medium. The organism was found to produce nodules in 

 the organs of inoculated animals. 



Korn isolated two acid-fast bacilli from Friburg butter. B. fri- 

 buryensis, No. 1, varies in morphology under different circumstances. 

 In preparations made from the organs of an inoculated animal, the 

 bacilli resemble in shape and size the B. tuberculosis of Koch. In 

 bouillon, the shape very much resembles the B. coli, but is a little 

 longer and slightly curved. On agar the bacilli are slightly thinner. 

 In old cultures upon agar and serum, they assume the aspect of 

 " Coccothrix." Upon potato they appear under form of cocci, diplo- 

 cocci, and specially of short, stout bacilli slightly curved. Upon 

 cooked beetroot at the end of three or four days the organisms 

 resemble staphylococci. They are shorter when grown at ordinary 

 temperature than when grown at 37 C. In culture media 

 the older growths generally exhibit some orange or red coloration, 

 though on almost all media the growth is at first white and 

 non-wrinkled. Upon glycerine-agar a thick, white, brilliant growth 

 occurs with deposit in the water of condensation, which is soon 

 covered with a veil adherent to the walls of the tube. Later 

 on the growth becomes slightly folded. At the age of about three 

 weeks the culture is creamy, presenting a few, light folds, and 

 of yellow-orange colour. In older cultures the growth is very 

 abundant, raised considerably above the surface, and irregularly 

 folded and convoluted, the colour varying in depth from light to 

 dark orange or even red brick (see Plate). Milk is not coagu- 

 lated, but at the end of three weeks possesses a yellowish-brown 

 colour. Subcutaneous or intraperitoneal injection of pure cultures 

 produce only an abscess at site. If injected with butter itself in 

 white mice, granulations are produced in thoracic and abdominal 

 viscera, showing no giant cells, but commencing caseation. 



B. friburgensis, No. 2, consists of a small rod two or three times 

 longer than broad, often irregular and sometimes clubbed. It is 

 much less sensitive to decolorisation by acid than No. 1 ; grows 

 feebly on ordinary laboratory media, with the exception of glycerine 

 agar, in which growth appears in twenty-four hours, and eventually 

 becomes abundant. The culture is creamy, glistening, and a 

 yellowish colour (see Plate). Milk turns of a dirty red colour in 

 about three weeks time. 



Markl, Tobler, Coggi, Binot, and Grassberger have also isolated 



