204 BACTERIOLOGY. 



decolorized. The latter may then be given a 

 contrast stain with a green or blue dye. With 

 this treatment the red tubercle bacilli stand 

 out in sharp relief against a green or blue back- 

 ground. The leprosy bacteria when once 

 stained, behave in almost the same manner but, 

 according to Baumgarten, they differ from the 

 tubercle bacteria in staining quickly and well 

 in a simple watery solution of fuchsin without 

 mordant. The syphilis bacteria are easily de- 

 colorized by mineral acids, the smegma and ear- 

 wax bacteria by alcohol. 



Actinomycosis in man was referred by B. 

 Langenbeck as far back as 1845 to the growth 

 of a mould, but was first accurately described 

 by J. Israel in 1878 ; the microbes were ob- 

 tained in pure culture by Bostro'em, M. Wolff 

 and J. Israel. Actinomycosis in cattle was rec- 

 ognized in 1877 by Bollinger, and the disease 

 was communicated to calves by Ponfick. When 

 bones, such as those of the jaw or the mastoid 

 process, are attacked by the suppuration ac- 

 companying this disease there are found small, 

 gritty, yellowish granules which consist of a 

 central core of tangled filaments, from which 

 club-shaped rays shoot out peripherally. The 

 threads are often branched and have the char- 

 acter of true sheathed filaments inside of 

 which both rod and coccus forms are found. 



