282 MICROBIOLOGY 



in this country. It is closely related to swine erysipelas. In 

 its morphology and cultural characters this organism does not 

 seem to differ from that of swine erysipelas except in the fol- 

 lowing points. Morphologically, the bacteria of mouse septi- 

 cernia are about one and one-half times as thick as those of 

 rouget ; the filaments are much shorter and less tortuous. On 

 agar there is no appreciable difference in the character of the 

 growth ; the colonies are slightly smaller in cultures of the 

 bacterium of rouget. In gelatin needle cultures the growth is 

 more dense, and not so diffuse as that of mouse septicemia. In 

 roll cultures the colonies of rouget bacteria consist of a central 

 opaque, nucleus with a hazy periphery, the whole about 3 mm. 

 in diameter, when the colonies are not crowded, and situated in 

 a liquefied area of gelatin, extending slightly beyond the border 

 of the colonies. The development in roll cultures is especially 

 interesting, as the solid nucleus is observed in a considerable 

 number of colonies of mouse septicemia. The bacterium of 

 mouse septicemia is more virulent for mice than that of rouget. 

 There seems to be a marked tendency on the part of both of 

 these organisms to invade the white blood corpuscles. 



It is interesting to note that in Europe where swine 

 erysipelas is more or less common, mouse septicemia is not rare. 



BACTERIUM OF CASEOUS LYMPH-ADENITIS. 



Synonyms. Bacillus of pseudo-tuberculosis Preisz and 

 Guinard 1 ; bacillus of caseous lymph-adenitis Norgaard and 

 Mohler 2 ; bacillus of Preisz. 



Place in nature. This organism is supposed to be the 

 cause of a disease known as caseous lymph-adenitis in sheep. 

 Old sheep suffer most with it. It has been described as pseudo- 

 tuberculosis by a number of writers. Norgaard and Mohler 

 give a full description of the disease, the bacterium and bibli- 

 ography. The organism was first described by Preisz and 



1 Preisz and Guinard. Jour, de med. vet. et de zoolich, Vol. XVI, 

 p. 563. 



2 Norgaard and Mohler. Annual Report B. A. I., U. S. Dept. 

 Agric., 1899, p. 638. 



