DISEASES OF CATTLE 261 



Heifer No. 406, about 18 months old; Heifer No. 386, about 

 16 months old; Cow No. 336, about 3 years old; Cow No. 215, 

 about 6 years old. 



One of the above animals (cow No. 336) died about four 

 months after injection without additional exposure to tuberculosis. 

 The cause of death was inflammation of the intestines, but she 

 showed a well-marked tuberculous lesion in her tail at the seat of 

 injection and tuberculous lesions in four mediastinal glands. All 

 other parts of her body were free from tuberculosis. 



Heifers 406 and 386 and cow 215 were killed after having 

 been exposed to a tuberculous environment for quite a long time, 

 and showed tuberculous lesions which might have been caused in 

 part by the exposure, and which were certainly caused in part by 

 the injection of tubercle bacilli. 



Injection Under the Skin of the Neck. On June 21, 1906, 

 the following 5 calves were each injected with 3 c. c. of a suspen- 

 sion of virulent human tubercle bacilli. The dose in each case was 

 divided into two parts, and one part was introduced under the 

 skin on the right side of the neck and the other part under the 

 skin on the left side of the neck. Each 3 c. c. of the suspension 

 injected represented 0.01 gram of tubercle bacilli. 



Bull calf No. 456, about 2V 2 months old; Bull calf No. 457, 

 about 3 months old; Bull calf No. 458, about 2^ months old; 

 Heifer calf No. 459, about 2V 2 months old; Heifer calf No. 4'62, 

 about 2 1 /<3 months old. 



Calves 458 and 462 died in about two months as a result of 

 tuberculosis caused by the injection of tubercle bacilli. The re- 

 maining three animals were exposed to a tuberculous environment for 

 some time and were subsequently killed and examined post-mortem. 

 All showed extensive lesions of tuberculosis, no doubt almost entirely 

 due to the injection of tubercle bacilli, showing that either this 

 method of treatment was too severe or that the culture of tubercle 

 bacilli used was too virulent. 



In addition to the foregoing subcutaneous injection, 10 calves, 

 Nos. 446, 460, 463, 464, 465, 466, 469, 470, 473, and 474, were each 

 given two successive injections of virulent tubercle bacilli, with an in- 

 terval between the two injections. These calves all contracted tuber- 

 culosis from the treatment received, and simply emphasized that sub- 

 cutaneous injections, no matter what part of the body is used as the 

 seat of injection, are dangerous when the bacilli injected have a true 

 virulence for cattle. In a later and fuller report on this work it is ex- 

 pected that the lesions caused by the various injections may be given 

 and discussed in detail. 



Among the subcutaneous injections only those made into the 

 ends of the tails of calves 449, 452, 453, 454, and 455 with virulent 

 human cultures hold out any encouragement that a subcutaneous 

 method of protective inoculations against tuberculosis can be de* 

 veloped. The results with these animals, however, are quite encour- 

 aging and indicate the advisability of making tests of successive in- 

 jections into the tails of cattle, beginning with fairly virulent cultures. 



