258 DISEASES OF CATTLE, SHEEP, GOATS, ETC. 



No. 439, killed March 29, 1909, after having been exposed about 

 16 months to a tuberculous environment. Tubercles in the posterior 

 mediastinal glands, which on guinea-pig inoculation caused general- 

 ized tuberculosis. 



TEST ACCORDING TO PEARSON'S METHOD. 



On June 2, 1906, the first 9 calves, and on June 12, the tenth 

 calf in the following list were given each an intrajugular injection of 

 3 c. c. of a suspension of tubercle bacilli of the human type. The 

 tubercle culture used to make the suspension was "Case 32," and each 

 cubic centimeter of the suspension was equal to 0.0013 gram of 

 tubercle bacilli. 



Heifer -calf No. 412, about 4 months old; heifer calf No. 413, 

 about 3 months old; bull calf No. 425, about 2 1 / to 3 months old; 

 bull calf No. 426, about 2V 2 to 3 months old; bull calf No. 428, about 

 2% to 3 months old; heifer calf No. 430, about 2 1 /2 to 3 months old; 

 bull calf No. 433, about 2V 2 to 3 months old; bull calf No. 440, about 

 2V 2 to 3 months old; heifer calf No. 442, about 2^ to 3 months old; 

 heifer calf No. 445, about 3 months old. 



The ages of the calves as given above refer to the date on which 

 the injections were made. On July 18, 1906, the 10 calves were given 

 a second intrajugular injection of a suspension of tubercle bacilli in 

 all respects relative to dose and strength similar to the first injection. 



On September 11, 1906, the calves received a third intrajugular 

 injection of a suspension of tubercle bacilli. The third dose, like the 

 other two, was 3 c. c., but the suspension was stronger, 1 c. c. being 

 equal to 0.002 gram of tubercle bacilli. 



With the exception of some elevation in temperature, most 

 marked after the third injection, the calves showed no pronounced 

 symptoms as the result of the injections. Of the 10 calves, 1 (No. 

 445) was killed and examined post-mortem without being exposed to 

 tuberculosis, to determine what lesions, if any, had been caused by the 

 three injections of tubercle bacilli. The remaining 9 calves were ex- 

 posed to a tuberculous environment, as follows : 



Nos. 412 and 425, October 30, 1906 ; Nos. 413 and 426, February 

 21, 1907; Nos. 428 and 430, April 25, 1907; No. 440, November 8, 

 1907. 



Control animals were added at the time of each exposure. The 

 character of the tuberculous environment has already been described. 



The dates on which the 10 calves were killed and a short memo- 

 randum of the lesions found on autopsy follow: 



No. 445, treated but not exposed, reacted to tuberculin Octo- 

 ber 17, 1907 (about 13 months after last bovo-vaccination injec- 

 tion), killed November 7, 1907. No lesions of disease. 



No. 412, killed April 23, 1908, after having been exposed to 

 a tuberculous environment about 18 months. No lesions of dis- 

 ease. 



No 425, died December 18, 1906, after having been exposed to 

 a tuberculous environment about 6 weeks. Cause of death, inflam- 

 mation of the intestines. No lesions of tuberculosis. 



