132 ILLINOIS STATE DAIRYMEN'S ASSOCIATION 



No. 4. Microscopical Examination of a Smear Preparation from 



the Swab. 



From every fresh sample a number of smear preparations 

 were made and stained according to Ziehl. 



No. 5. Animal Inoculation Experiments. 



Whereas in the beginning we merely washed the swab in a 

 sterile normal salt solution, which was subcutaneously injected 

 into Guinea Pigs. From No. 30 on, the entire swab was used 

 after taking only enough for a smear preparation. The reason 

 for this change was that very often after washing and inocu- 

 lating this material into guinea pigs, they would not contract 

 the disease while microscopical examinations of the material 

 showed tubercle bacilli. On the other hand the inoculation of 

 the entire swab into guinea pigs showed eight positive results 

 where the existence of the tubercle bacilli in the smear prepara- 

 tion could not be found. It is therefore advisable in nearly all 

 cases to resort to animal inoculation and to use the whole swab 

 inasmuch as our observations have shown that animals stand this 

 method very well. 



No. 6. Post Mortem Examination of Animals Six Weeks Later. 



The general plan of observing animals inoculated six weeks 

 can be terminated much sooner. In six cases the symptoms were 

 prominent in ten days (cases Nos. 32, 36, 46, 49, 51 and 53). 



The following table shows our experimental data and we 

 wish to again emphasize that the first twenty-nine (29) cases 

 of inoculations were those of a washed solution and all remain- 

 ing ones were inoculated with the whole swab. Of the fifty- four 

 (54) cattle physically examined and declared tubercular, fifty- 

 two (52) cases upon post mortem examination revealed more 

 or less tuberculosis, thirty-five (35) had lung tuberculosis, eleven 

 (11) had tuberculosis of the lung and other organs, especially 

 the pleura, three (3) had tuberculosis of the serous membrane 

 (Miliary) while only three had tubercular lymphatic glands. In 



