That this free distribution of the protective virus for tuberculosis of cattle has been completely justified is seen by the report of Koch’s Institute, entitled, “_Ueber Immunisierung gegen Tuberculose_.” To be sure, this report contains nothing positive that, as a result of a large number of experiments, I had not already maintained for some years. And it lacks, what is especially important in the practical immunization of cattle, namely, proof in the form of protocols. Possibly these were omitted because they would fail to substantiate Neufeld’s assertion that Koch, previous to my publication regarding protective inoculations of cattle with living tubercle bacilli, had already made use of the same procedure. I cannot refrain from observing that Neufeld treats this question of priority in rather unusual fashion, for he now claims for Koch an immunizing procedure which I had published as long ago as 1901. It would surely have been more reasonable to have made these claims sooner, before the success of the method became so generally recognized in agricultural circles. Finally I must criticise the author for making similar uncalled-for claims for the English investigator Macfadyan. As the one most concerned, such claims might have been made by Macfadyan himself, yet, so far as I know, that investigator has not even suggested such a thing. In the case of my diphtheria-serum discovery I can entirely overlook similar baseless and unjust claims for Roux and for Ehrlich. Such claims have often been made by medical authors, but neither Roux nor Ehrlich has ever authorized such a perversion of facts. However, apart from these inaccuracies, the report of Neufeld regarding Koch’s tubercular immunizing experiments shows an agreement with my results which extends into the smallest details. This, then, must demonstrate to the world the absolute reliability of my immunizing principle. The entire suppression of bovine tuberculosis is now only a question of conscientious and properly conducted protective inoculations, and, of course, also a matter of time. Just now I am studying the important practical point which for a long time occupied the attention of students of vaccination. We now know that protection against variola is only then secured when the vaccination is followed by a typical inflammatory reaction. Are the requirements the same for bovine tuberculosis? This I cannot yet definitely answer; and even under the most favorable conditions I shall be able to answer it only after a lapse of two years. By that time the calves that were injected only once and that did not, so far as we could ascertain, react to the inoculation, will have grown to maturity.