ANTHRAX. 361 On potato the growth is white, creamy, sometimes rather dry in appearance. Sporulation is marked. Blood-serum cultures lack peculiarities; the culture- medium is slowly liquefied. The bacillus only grows between the extremes of 20° and 45° C., best at 37° C. The exposure of the organ- ism to the temperature of 42-43° C. for twenty-four hours is sufficient to destroy its virulence. The culture-media should always be faintly alkaline, as anthrax bacilli will not grow in the presence of free acid. The micro-organism under consideration is a parasitic microbe, yet is one which, because of its spores, can, in .a latent form, exist without the animal organism until .appropriate conditions for its natural development are presented. Ordinarily, the infection takes place either through the respiratory tract or through the alimentary canal. Buchner has shown that when animals are allowed to inhale anthrax spores they die of typical anthrax. The spores establish themselves in the alveoli of the lung, penetrate the epithelium, enter the vascular sys- tem, and soon give rise to typical lesions. Strange to say, the appearance caused by the inhalation of the bacilli in their perfect form is entirely different, for a rapid multiplication occurs without Sporulation, and causes a violent irritative pneumonia with serous or sero- fibrinous exudate in which large numbers of the bacilli occur. In these cases there may be no general infection. When the bacilli are taken into the stomach in food they meet with a rapid death because of the acidity of the gastric juice. Should spores, however, be ingested, they are able to endure the gastric juice, to pass into the intestine, and, as soon as proper conditions of alkalinity are encountered, to develop into bacilli. They develop rather rapidly, surround the villi with thick networks of bacillary threads, separate the epithelial cells, enter the lymphatics, and thus find the appropriate environ- ment for the production of a general infection.