362 MICROBIOLOGY 



is stained by aniline gentian violet, carbol fuchsin and by 

 Gram's method. 



In the discharges of actinomycotic lesions the ray fungus 

 may be detected as very fine yellowish granules. When ex- 

 amined microscopically, these appear as rosettes, sometimes 

 showing central filaments with the terminal rays radiating 

 apparently from a common center. They can be seen in the 

 fresh preparation but frequently they appear with greater 

 clearness if a few drops of a 10% caustic potash solution are 

 added. 



The natural habitat of Actinomyces bovis is thought to 

 be on certain grasses, especially the barley (Hordeum 

 murinum). It is quite widely distributed but the disease ap- 

 pears more frequently in some localities than in others. Its 

 most common seats are in the jaw (lumpy jaw), in the tongue 

 (wooden tongue) and in the lymph glands. The lesions, how- 

 ever, may occur in any organ. Assmann 5 has collected 11 

 cases of generalized actinomycosis in cattle and hogs. 



ACTINOMYCES PULMONALIS BURNETT. 



Place in nature. In 1910, Burnett described an acti- 

 nomyces (streptothrix) which he had isolated from the lesions 

 in two bovine lungs which were thought by those making the 

 post mortem to be tuberculous. He obtained the organism in 

 pure culture on potato. It grew, however, in bouillon, forming 

 at first a delicate membrane on the surface and minute whitish 

 spherical colonies in the depth and clinging to the sides of 

 the tube. These are composed of long branched filaments. On 

 agar minute translucent colonies appeared. The growth be- 

 comes thicker and finally presents a flat whitish raised mass. 

 On glycerin agar its growth was less vigorous than on plain 

 agar. On potato the young colonies are convex in form and 

 translucent. Later they become confluent, the surface cov- 

 ered with a much convoluted, lemon yellow growth which later 

 becomes chalky white, this being due to short threads growing 



5 Assmanru Deutsche tierartz. Wochenschrift, 1904. 



6 Burnett. Ann. Kept. N. Y. State Vet. College, 1910, p. 167. 



