226 BACTERIA 



ture grows down into the agar, and the medium darkens. Old 

 cultures 'are dark and crumbly looking, adhere firmly to the agar, 

 and have a downy dust-like covering. On blood serum the colo- 

 nies appear as dewdrops, which later become brownish, then, 

 yellowish-orange, or brick-red. In bouillon the growth is at the 

 bottom in ball-like masses that cohere firmly. Clubs do not form 

 in this medium. The supernatant bouillon is clear, with no sur- 

 face growth. In milk it produces no chemical change. On 

 potato it grows in knot-like colonies. 



Pathogenesis. Causes in cattle the disease known as "lumpy 

 jaw." The fungus reaches the jaw from the teeth and gums, the 

 latter first being injured by sharp spines in the food. In man, the 

 internal organs, lungs, intestines, and, rarely, the brain become 

 infected. The liver often is abscessed. In both cattle and man 

 universal actinomycosis sometimes occurs. The lesions produced 

 are rather massive at times; the nidus is often surrounded by 

 enormous numbers of polynuclear leucocytes, which, no doubt, 

 play a defensive role in the tissues. The disease is often fatal to 

 cattle and to man. It is hard to inoculate laboratory animals 

 with the disease, though Wright succeeded in so doing. No 

 useful immunity reactions seem to occur.- Vaccines have been 

 used in treatment with encouraging results but no cures. Potas- 

 sium iodide internally is always indicated. 



ACTINOMYCES MADURA 



Actinomyces Madura. 



Streptothrix Madura, Vincent. 



Morphology and Stains. A non-motile, non-flagellated organ- 

 ism said to have spores. Its growth resembles that of A ctinomyces 

 boms. It consists of long threads that are clubbed. These stain 

 by all the basic aniline dyes and by Gram's method. There are 

 three recognized forms of this organism, white, black and red, 

 which have been found in various cases but the interrelation of 



