On examining the blood of animals, the subjects of "splenic fever," some French pathologists had discovered the presence of certain minute transparent filaments which, by the investigations of a German physician named Koch, were proved to be a fungoid plant developed from germ particles of microscopic minuteness. By gradual extension these minute particles, termed "microbes," attain the form of small threads or rods, to which the name of "bacilli" has been given, from the Latin _bacillus_, a rod or staff. These rods were found to be in fact hollow tubes, divided at intervals by partitions, which, on attaining full growth, break up into fragments, the interiors of which are found to be full of minute germs similar to those from which the rods were at first developed. These germs were found by Koch and his collaborateurs to be capable of cultivation by being immersed in some suitable organic liquid kept at a proper temperature, and the supply could be kept up by introducing even a few drops of such impregnated fluids into other fluids, and repeating the process again and again. The next step to test the potency of these germs to generate the disease in animals whence they were originally obtained, was to vaccinate animals with a few drops of the fluid thus artificially infected. Accordingly it was found that the bodies of guinea-pigs, rabbits, and mice thus inoculated became infected, and developed all the characteristic symptoms of splenic fever or carbuncular disease. Pasteur, whose enthusiasm in the pursuit of investigations which had already been crowned with such signal success kept him awake to all that was being done by other inquirers, and made him watchful of every event that transpired relative to the epidemic diseases of cattle, was struck with the fact that some of the most fatal outbreaks of "charbon" among flocks of sheep occurred in the midst of apparently the most healthy pastures. His sagacity led him to inquire what had been done with the carcasses of animals that had died from previous outbreaks of the disease in these localities, when he found that they had been buried in the soil and often at great depths, of the same pastures. But how could the disease germs make their way to the surface from a depth of eight or ten feet? Earthworms, he guessed, might have conveyed them. And notwithstanding the incredulity with which his explanation was received, he forthwith proceeded to verify his supposition. Having collected a number of worms from the ground of the pastures in question, he made an extract of the contents of the alimentary canal of the worms, and with this he inoculated rabbits and guinea-pigs, gave them the "charbon" in its most fatal form, and proved the identity of the malady by demonstrating that the blood of the victims swarmed with the deadly "bacillus." And here we cannot but stop to notice the remarkable confirmation that is thus given to the wonderful and beautiful