192 



Xo. 3. Grade Jersey cow, six or seven years old, and in poor 

 condition. Reaction niedinni in size. Lesions : The mediastinal 

 lyniph glands contained nodular masses of tuberculous material. 

 The diaphragmatic lobes of both lungs contained large masses of 

 inspissated tuberculous material with cavities opening directly into 

 the bronchial tubes. 



No. 4. Holstein heifer, two years old and in prime condition; 

 reaction medium size. Lesions : The only lesion which could be 

 found after a careful post-mortem examination was in the left 

 retro-pharyngeal lymph gland, which was greatly enlarged and 

 filled with small nodules about a quarter inch in diameter. 



No. 5. Pure-bred Jersey bull in fine condition and dressing 

 687 lbs. Reaction very large, a swelling the size of an orange 

 appearing at the point of injection. Lesions: The disease was in 

 Its earliest stage, there being few lesions. The retro-pharyngeal 

 and mediastinal glands contained a few small nodules. 



No. 6. Pure-bred Jersey bull in fine condition and dressing 

 about 700 lbs. Reaction very large, though slightly smaller than 

 in the previous bull. Lesions : The lesions were confined to the 

 retro-pharyngeal glands and consisted of five or six nodules all 

 about the same size, viz., three mm. in diameter. Lesions were 

 not observed in any other part of the body, thus showing the in- 

 fection to be of very recent origin. 



In the above six cases practically all grades of reactions were 

 observed, from the smallest to the largest, and with these reac- 

 tions the corresponding stages of the disease as disclosed by the 

 lesions on post-mortem examination, with the one exception of the 

 generalized case, and a reaction in such a case would be of the 

 small type. 



A study of the different types of reactions to the intradermal 

 test in connection with the amount of disease found on post- 

 mortem examination has established a certain definite relation 

 between the size of the swelling at the ])oint of inoculation and 

 the amount of disease present in the animal system, so that it 

 may be laid down as a rule that the more recent the infection and 

 conse(|uently the fewer and smaller the number of lesions the 

 larger will be the reaction. 



Reactions of this method of testing. dei)ending as they do on 

 the anaphylactic conditiou of the tissues, will vary as this hyper- 

 sensitive condition varies, and naturally (he highesl slate of 

 anaphylaxis will obtain wlu-n the tissues of the IxkK- are making 

 their first fight against the invading organisms and the death- 

 d.ealing toxins first begin to circulate in the blood stream. 



When the disease has become established in the body and has 

 formed larger or small localized lesicms dv has l)eri>me generalized, 

 the tissues, through habit and llu' long continued presence of 

 toxins circulating through them, gradually lose their highly-sensi- 

 tized condition and so respond less to the injection of (uberoidin. 



