GENUS BACTERIUM 283 



Guinard and later by Preisz." The disease is found in Europe, 

 Australia, South America and the United States. It is prob- 

 ably widespread in sheep-raising districts. In addition to its 

 presence in this disease it has been found by Nocard 4 in a case 

 of ulcerative lymphangitis in horses. Kitt 5 found it in a case 

 of caseous broncho-pneumonia in cattle. The further distribu- 

 tion of the organism is not known. 



Morphology. This bacterium varies somewhat in size 

 and shape according to the medium in which it has grown. It 

 seems to be characterized by its variation in shape. It is short 

 and thick with rounded ends. In tissues it is reported to ap- 

 pear often as nearly spherical bodies although dumb-bell or 

 club-shaped forms may be present. They vary from 1.3 to 

 1.6 p in length. They are about 0.5 //, thick. In young cultures 

 longer forms are observed. The ends may be swollen and 

 somewhat refractive and stain more deeply than the other part. 

 In old agar cultures ovoid forms appear often in clumps. It 

 does not form spores. Vacuoles and capsules have not been 

 observed. 



Staining 1 . It stains w r ell with carbol fuchsin and alkaline 

 methylene blue. It takes the Gram stain. 



Cultivation. It is readily cultivated on agar and in 

 bouillon by inoculating tubes of these media with portions of 

 the caseous lymph glands. The growth is very slow at first but 

 subcultures develop more quickly. 



Agar. The growth on slant agar is quite characteristic. 

 If a loopful of the caseous material is drawn over the surface 

 there will appear in the course of four or five days a limited 

 number of well isolated colonies, showing at first as grayish 

 white points. On about the twelfth day they will have attained 

 their full size, that is, 4 to 6 mm. in diameter, appearing as a 

 thick white expansion, more or less rounded, with a shiny, wax- 

 like, slightly granular surface marked by wavy concentric 

 rings arranged parallel to the margin. The colonies have 



3 Preisz. Ann de 1'Inst Pasteur, Vol. VIII (1894) p. 231. 

 ^ 4 Nocard. Compt. rend, de la Soc. de Biol., Vol. I (1899) p. 608. 

 Kitt. Monatshefte f. prak. Thierheilkund, Vol. I (1890) p. 145. 



