630 INFECTION AND IMMUNITY. 



later, Bellinger, in 1877, gave the first accurate de- 

 scription of the disease in cattle, and in 1878 J. 

 Israel described it as a new disease in man. A 

 short time later Ponfick demonstrated the identity 

 of bovine and human actinomycosis. 



The specific organism, Actinomyces bovis et 

 hominis, on culture media consists of a mass of del- 

 icate threads which exhibit "true branching" and 

 which, to a certain extent, segment to form 

 "spores." The radially arranged groups of cells 

 which occur as somewhat characteristic sulphur- 

 yellow macroscopic granules in the pus of the actin- 

 omycotic abscesses, and which give to the organ- 

 ism the name of "ray fungus," are essentially a 

 manifestation of parasitic existence, although col- 

 onies developing on media which contain serum 

 or ascitic fluid may show a degree of "club" for- 

 mation (Wright). Each granule represents a col- 

 ony of organisms the members of which possess 

 club-shaped extremities, and in the center of the 

 mass and extending from it are many of the deli- 

 cate threads found in cultures of the organism. It 

 grows on various culture media, often as a mold, 

 and stains by Gram's method. 



Resistance. The actinomyces is an organism of considerable 

 resistance. Cultures remain alive for one year or 

 more when in a dried condition and the spores in 

 one instance germinated after having been pre- 

 served for six years. A temperature of 80 C. 

 'or fifteen minutes kills the spores (Berard and 

 Vicolas). When suspended in bouillon, spores are 

 milled in fifteen hours by direct sunlight, but when 

 thoroughly dried, approximately ten days' expos- 

 ure produced no injury. 



