GENUS BACTERIUM 291 



Alkaline bouillon containing 1 per cent dextrose in the 

 fermentation tube becomes cloudy within twenty-four hours 

 after inoculating and strongly acid in reaction. Similar tubes 

 of bouillon containing saccharose and lactose become clouded 

 throughout but they remain alkaline in reaction. The degree 

 of alkalinity increases with age. Gas is not produced during 

 the growth in bouillon containing these sugars. 



Life conditions and properties. This organism develops 

 at a temperature from 20 to 41 C. It does not grow well in 

 acid media. It produces indol. 



Resistance. It is destroyed at 50 C. in fifteen minutes. 

 A \% solution of carbolic acid was fatal to it in 5 minutes. It 

 resists drying when in films on cover-glasses for from 7 to 15 

 days. 



Pathogenesis. This organism is fatal to fowls, pigeons, 

 rabbits, guinea pigs, and mice. Other animals have not been 

 tested. Excepting in intravenous injections, comparatively 

 large quantities of a pure culture were required to produce 

 fatal results. Fowls inoculated in the wing vein with 0.3 cc. 

 of a fresh bouillon culture died in from three to thirteen days ; 

 usually on the fifth or sixth day. The temperature begins to 

 rise on the second day after inoculation. It reaches 109 to 

 111 F. a few days before death occurs. In cases where the 

 fowls live from five to six days they appear perfectly well for 

 at least three days, when the feathers begin to have a slightly 

 ruffled appearance. Pigeons inoculated with 0.2 cc. of a bouil- 

 lon culture die in from four to five days. In rabbits the lesions 

 resemble very closely those produced by attenuated hog cholera 

 bacteria (B. suipestifer) . Guinea pigs inoculated in the ab- 

 dominal cavity with from 0.2 to 0.3 cc, of a bouillon culture 

 die in from five to eight days. 



BACTERIUM TRUTTAE MARSH. 



Synonyms. The bacterium of a specific disease of brook 

 trout. 



Place in nature. Marsh 1 discovered this organism as 

 1 Marsh. U. S. Fish Commission Bulletin, 1902, p. 411. 



