48 Veterinary Medicine. 



teria given under hog cholera. It is a short rod, with rounded 

 ends, 0.8 to 1.5/u. x 0.6 to 0.8/x., staining readily in aqueous basic 

 aniline colors and bleaching in Gram's iodine solution. The 

 staining is distinctly polar, the colored portions being more or 

 less crescentic with the concave or straight border turned inward 

 toward the central clear space. It is destitute of flagella and dis- 

 tinctly nonmotile unlike the very active bacillus of hog cholera. 

 It further differs in its growth on potato which is slight, gray and 

 waxy. On gelatine, too, it gives a feeble growth (or none) un- 

 like the brownish colonies of the bacillus of hog cholera. It fails 

 to liquefy gelatin. On agar the growth is more active, being 

 grayish, translucent or brown. Those forming under the surface 

 are like flat horizontal discs with a small microscopic elevation or 

 knob in the center. It grows in milk producing little or no acid 

 and no clot. It produces gas with none of the sugars — glucose, 

 lactose, saccharose — in contrast with the gas production in glu- 

 cose by the hog cholera bacillus. It shows much less vitality and 

 hardihood than the hog cholera bacillus, growing but feebly 

 between 65 and 7o°F., and most actively at 97° to ioo°F. ; dying 

 in 7 minutes at a temperature of 58 (moist ); dying in 3 days 

 when dried, in 4 to 6 days in the soil, in 10 to 15 days in water 

 and instantly in 0.04 per cent solution of lime water. 



Pathogenesis. It is pathogenic to swine, hens, pigeons, pheas- 

 ants, sparrow, mice, guinea pigs, rabbits, cattle, deer, etc., show- 

 ing not only a wider range than the hog cholera bacillus, but a 

 more deadly action outside the genus suis. Inoculated birds die 

 in 2 days, rabbits in 16 to 20 hours and guineapigs in 1 to 4 days. 



Accessory Causes. These agree in the main with those of hog 

 cholera already described so that it is needless to repeat them 

 here. The principal distinctions depend on the lesser vitality 

 of the swine plague bacillus outside of the animal body, and its 

 wider range of pathogenesis outside the genus suis. Infecting 

 materials that have been thoroughly dry for a week may be con- 

 sidered harmless, also that which has been more than two weeks 

 in water, and that which has been more than a week in the soil. 

 If, therefore, the buildings have been thoroughly disinfected, the 

 simple disuse of yards and pastures for a fortnight, and of ponds 

 of water for three weeks may suffice. In the case of hog 

 cholera it may be necessary to abandon such places for 5 months 

 or for the season. 



