BUREAU OF ANIMAL INDUSTRY. 



641 



injections of heated cultures until a large amount had been intro- 

 duced into the system would be more efficacious in producing im- 

 munity. For this purpose the culture liquids were concentrated, by 

 using a 2 per cent, solution of meat extract with 2 per cent, peptone 

 for some of the injections; for the remainder a 2 per cent, solution 

 of peptone in beef infusion. The cultures were made in Erlenmeycr 

 flasks, 23lugged with cotton wool. 



The table given below gives the date of the injection and the quan- 

 tity used each time. It will be noted that I^os. 191 and 194 received 

 two. Nos. 210 and 218 three, and Nos. 219 and 221 four doses each of 

 the heated culture liquid. The injections were made two days apart, 

 the exposure in the infected pen and among diseased animals about 

 one week after the last inoculation. Nos. 220, 232, and 235 were 

 placed in the infected pen at the same time, to determine the virulence 

 of the infection upon jDigs which had not received any injection. 



* Checlis. 



All of the inoculated and control animals died within periods rang- 

 ing from thirteen to nineteen days, only one living thirty-nine days, 

 and this one a control animal. Of those that had received two doses. 

 No. 191 died May 23 (nineteen days after exposure), with considerable 

 ulceration in caecum and colon. No. 194 died May 19, with extensive 

 and deep congestion of the lymphatic glands in general, of the kidney, 

 stomach, and large intestine. In the latter, ulceration was not yet 

 begun. No. 216, which had received three doses, died very unex- 

 pectedly thirteen days after exposure. The lesions were of the hem- 

 orrhagic type, involving extravasations and ecchymoses of the intes- 

 tinal tract, more especially of the large intestine, heart, lungs, lym- 

 phatic and subcutaneous fatty tissue. Ulceration in large intestine 

 very slight, the congestion being intense. No. 218, treated like the 

 former, died fifteen days after exposure. The lesions were like those 

 of No. 216, but not so severe. Ulceration as yet very slight. 



No3._ 217 and 221, which had received four injections, died fifteen 

 and nineteen days after exposure, respectively. The lesions in No. 

 217, which died very suddenly, were of hemorrhagic character, the 

 ulceration in the csecum and colon being quite superficial. In No. 

 221 the ulceration was more pronounced, the general congestion and 

 extravasation much less so. 



Of the control animals the lesions of No. 220 were of the hemor- 

 rhagic type, resembling those of No. 194 very closely. In No. 232 

 there was extensive ulceration of the mucous membrane of the large 

 intestine. In No. 235, which lived for thirty-nine days after expos- 

 ure, the mucosa of the caicum and upper portion of the colon was 

 involved in complete necrosis nearly 5"™ thick. Beyond this the ne- 

 41 AG^'80. 



