130 Journal of Agricultural Research voi. xiii, no. 2 



cholera-infected pigs. The two rats were then killed; the bodies were 

 chopped up in their entirety and, mixed with bran mash, were fed to two 

 susceptible pigs, No. 11 18 and 11 19. 



The two pigs were kept under observation from November 4 to 24, a 

 period of 20 days, and remained well. They were exposed to hog cholera 

 by virus injection on November 24, showed the first symptoms of sickness 

 on November 29, developed the usual cholera symptoms, and were killed 

 for virus on December i. Both pigs showed slight but characteristic 

 lesions at autopsy. 



Experiment XVIII. — Two gray rats which were caught on the Sta- 

 tion premises were fed daily from October 31 to November 20, a period 

 of 21 days, with the meat of cholera-infected pigs. The two rats were 

 killed on November 21. They were then chopped up, mixed with bran 

 mash, and fed to two susceptible pigs, No. 1174 and 1175. The pigs 

 were under observation from November 21 to December 8, a period of 

 17 days, and remained well. The pigs were exposed to hog cholera by 

 virus injection on December 8, showed the first visible symptoms on 

 December 11, developed the usual cholera symptoms, and were killed 

 for virus on December 15. Each pig showed hemorrhagic lesions of hog 

 cholera at autopsy. 



In these experiments rats which had been fed on the meat of cholera 

 pigs for 5 days and 21 days, respectively, were killed and the entire 

 carcasses fed to susceptible pigs without producing sickness. 



GENERAL SUMMARY AND CONCLUSIONS 



Although the data obtained from these experiments are not sufficient 

 to warrant sweeping conclusions, the results are nevertheless quite sug- 

 gestive, and they serve to bring out some interesting points which may 

 be summarized as follows : 



(i) The eye and nose secretions, the blood, the urine, and the feces of 

 cholera-infected pigs were tested on the first, second, third, fifth, seventh, 

 and ninth days after infection. When injected, the eye and nose se- 

 cretions and fecal suspensions, were found to be infectious on the 

 third day; the urine was quite regularly infectious by the fourth or 

 fifth day and the blood was infectious as early as the first day. When 

 fed and when scattered in pens, the freshly collected secretions 

 and excreta were noninfectious as a rule. Secretions and excreta 

 which were held at room temperature (60° to 85° F.) for 24 hours re- 

 mained infectious when injected. When the secretions and excreta were 

 held at the same temperature for 48 hours the urine and feces re- 

 mained infectious, but the eye and nose secretions were no longer so. 

 It might appear, therefore, that outside the animal body the virus 

 in the eye and nose secretions succumbs more quickly than the virus 



