IN SUSCEPTIBLE ANIMALS. 503 



passages of such domesticated animals as cattle, dogs, and cats" 

 (Smith). 



BACILLUS OF CHOLERA IN DUCKS. 



Obtained by Cornil and Toupet (1888) from the blood of ducks, in the 

 Jardin d'Acclhnation at Paris, which had died of an epidemic disease charac- 

 terized by diarrhoaa, feebleness, and muscular tremors, and which resulted 

 fatally in two or three days. 



Morphology. Does not differ in its morphology from the bacillus of 

 fowl cholera (Bacillus septicaemias hsemorrhagicae) ; short rods with rounded 

 ends, from 1 to 1.5 11 in length and 0.5 ju broad. 



Stains with the usual aniline colors, but not by Gram's method ; the ends 

 stain more deeply than the central portion. 



Biological Characters. An aerobic, non-liquefying, non-motilebacillus. 

 Does not form spores. Grows in the usual culture media at the room tem- 

 perature. In its growth in various media, as well as in its morphology, Cornil 

 and Toupet found this bacillus to correspond with the bacillus of fowl 

 cholera. In gelatin stab cultures the growth upon the surface consists of a 

 thin, grayish layer, and along the line of puncture as small, semi transpa- 

 rent, slightly yellowish, spherical colonies. Upon agar, in the incubating 

 oven, at the end of twelve hours small, lentil shaped, waxy colonies are 

 formed, which later may have a diameter of three to four millimetres. 

 Upon potato circular, yellowish colonies are formed, which become con- 

 fluent and form a somewhat depressed, pale-yellow layer. 



Pathogenesis. According to Cornil and Toupet, this bacillus is patho- 

 genic for ducks, but not for chickens or pigeons, and only kills rabbits when 

 injected in considerable quantity. Ducks die in from one to three days 

 from subcutaneous injections, or by the ingestion of food to which the bacil- 

 lus has been added. 



BACILLUS OF HOG CHOLERA (Salmon and Smith). 



Synonyms. Bacillus of swine plague (Billings) ; Bacillus of swine- 

 pest (Selaiider). 



According to Smith, this bacillus was first described by Klein 

 (1884) ; it was first obtained in pure cultures and its principal char- 

 acters determined by Salmon and Smith (1885), and has since been 

 studied in cultures and by experimental inoculations by Selander, 

 Billings, Frosch, Welch, Caneva, Bunzl-Federii, and others. 



The bacillus is found in the blood and various organs of hogs 

 which have succumbed to the infectious disease known in this country 

 as hog cholera ; and also in the contents of the intestine, from which 

 it may be obtained by inoculations into rabbits, but is not easily iso- 

 lated by the plate method owing to the large number of other bac- 

 teria present (Smith). 



Morphology. Short bacilli with rounded ends, 1.2 to 1.5 /* in 

 length and 0. 6 to 0. 7 /* in breadth ; usually united in pairs. 



This bacillus is easily stained by the aniline colors usually em- 

 ployed, but does not retain its color when treated by Gram's method. 

 When the staining agent is allowed to act for a very short time the 

 ends of the rods may be stained while the central portion remains 

 unstained. 



