M. Chamberland, a pupil who became intimately associated with this work on anthrax, has defined as follows what Pasteur had now achieved: “By his admirable process of culture outside organism, Pasteur shows that the rods which exist in the blood, and for which he has preserved the name of bacteridia given them by Davaine, are living beings capable of being indefinitely reproduced in appropriate liquids, after the manner of a plant multiplied by successive cuttings. The bacterium does not reproduce itself only under the filamentous form, but also through spores or germs, after the manner of many plants which present two modes of reproduction, by cuttings and by seeds.” The first point was therefore settled. The ground suspected and indicated by Davaine was now part of the domain of science, and preserved from any new attacks. Yet Jaillard and Leplat’s experiments remained to be explained: how had they provoked death through the blood of a splenic fever victim and found no bacteridia afterwards? It was then that Pasteur, guided, as Tyndall expressed it, by “his extraordinary faculty of combining facts with the reasons of those facts,” placed himself, to begin with, in the conditions of Jaillard and Leplat, who had received, during the height of the summer, some blood from a cow and a sheep which had died of anthrax, that blood having evidently been abstracted more than twenty-four hours before the experiment. Pasteur, who had arranged to go to the very spot, the knacker’s yard near Chartres, and himself collect diseased blood, wrote to ask that the carcases of animals which had died of splenic fever should be kept for him for two or three days. He arrived on June 13, 1877, accompanied by the veterinary surgeon, M. Boutet. Three carcases were awaiting him: that of a sheep which had been dead sixteen hours, that of a horse whose death dated from the preceding day, and that of a cow which must have been dead for two or three days, for it had been brought from a distant village. The blood of the recently diseased sheep contained bacteridia of anthrax only. In the blood of the horse, putrefaction vibriones were to be found, besides the bacteridia, and those vibriones existed in a still greater proportion in the blood of the cow. The sheep’s blood, inoculated into guinea-pigs, provoked anthrax with pure bacteridia; that of the cow and of the horse brought a rapid death with no bacteridia. Henceforth what had happened in Jaillard and Leplat’s experiments, and in the incomplete and uncertain experiments of Davaine, became simple and perfectly clear to Pasteur, as well as the confusion caused by another experimentalist who had said his say ten years after the discussions of Jaillard, Leplat and Davaine.