82 EXPERIMENT STATION RECORD. 



found altogether too expensive and too elaborate for application to the average 

 farm. For this reason it is utilized less and less even in Denmark, where gov- 

 ernment aid is secured in carrying it out. The chief objection to Bang's 

 method is the great increase in the amount of labor necessary to maintain two 

 separate herds on different parts of the fann and prevent infection from spread- 

 ing from one to the other. Moreover, the repetition of the tuberculin test at 

 frequent intervals has been found to l)e a considerable hardship. The author 

 believes that Bang's method is practical in localities where only a few herds are 

 affected or in herds where the number of tuberculous animals is not great. In 

 Saxony, however, with two-thirds of the cattle tuberculous, the method is con- 

 sidered quite unpractical. 



Ostertag's system of eradication consists simply in the destruction of cattle 

 affected with tuberculosis to such an extent that it may be readily recognized 

 by physical symi)tonis and the rearing of calves under conditions which prevent 

 infection. This method does not require the separation of the herd into tubercu- 

 lous and healthy groups, but merely reciuires, as soor; as the disease becomes 

 advanced far enough so that the animals may spread it by coughing or other- 

 wise, that such animals be destroyed. The c-alves are reared on ])asteurized or 

 sterilized milk or on the milk of other healthy cows. While Ostertag's method 

 may not seem to satisfy sanitary requirements so strictly as that of Bang, 

 it is much less expensive, more easily put in operation by the average farmer, 

 and. as experience has shown, almost if not equally effective. The author 

 believes that Ostertag's method is not capable of eradicating tuberculosis, at 

 least within a short time, in a herd without separation of diseased animals, but 

 that it does prevent a further infection and that the method is particularly 

 applicalile to the conditions in Saxony. 



Experiments with milk artificially infected with tubercle bacilli, E. C. 

 ScHKOEDER and W. PI Cotton {U. S. Dept. Ai/r., Btir. Aiiiiti. Indus. Bid. SO, pp. 

 18). — Three degrees of infectiousness were artificially in'oduced in milk l)y 

 adding 1 loop of a culture of tubercle bacilli to 10 cc. of milk from which other 

 degrees of infectiousness were obtained by diluting 10 times and 100 limes. 

 Guinea pigs fed on the milk which contained the largest number of tubercle 

 bacilli became infected without exception after feeding on this material 30 days 

 and in 33i per cent of cases after being fed 1 day. Guinea pigs fed on milk 

 containing a more dilute infection did not become diseased. Evidence was 

 obtained, however, that guinea pigs ai"e not very susceptible to infection with 

 tuberculosis through the alimentary tract. 



Hogs were inoculated subcutaneously with cultures of tubercle bacilli obtained 

 from man and animals. In all 12 hogs were used in the experiments. It 

 appears from these experiments that the high susceptil)ility of guinea pigs to 

 tuberculosis liolds good only when infection is made in the abdominal cavity, 

 veins, thorax, or subcutaneous tissue. During the experiments, 52 guinea pigs 

 and hogs were fed on milk containing small quantities of tubercle bacilli, with 

 the result that none of the guinea pigs were affected, while 5 out of the G hogs 

 contracted tuberculosis. The experiments indicate clearly that the localization 

 of tuberculosis in the lung gives no hint as to the point at which infection took 

 place. The lung may readily become infected by tubercle bacilli which enter the 

 body at some other point. The authors conclude that the experiments "direct 

 special attention to the danger sustained through exposure to tuberculous mate- 

 rial that enters tlic body with the food. This fact can not be too strongly 

 emphasized." 



Behavior of the cows' udder toward artificial infection with human and 

 bovine tubei'cle bacilli, L. Meyer (Ztschr. Tienned., 10 (1906), Xus. 3. pp. 



