_Epidemic meningitis._—On the contrary the disease may well be compared with epidemic meningitis. The germ of this disease, distributed throughout the world, is usually in an avirulent form and produces no epidemic of meningitis. Only an occasional case arises. There are certain localities in which the disease is particularly prevalent at all times. We may speak of these as endemic foci, but must remember that at the same time the virus is distributed elsewhere. Thus South Carolina, Missouri and Kansas have been shown to be localities in which meningitis has been more or less widely distributed for some years. We can carry the analogy still farther. During the concentration of forces early in the war, camps were established at Columbia, S. C. and at Fort Riley, Kansas. In these camps, Jackson and Funston, there very rapidly developed quite extensive epidemics of cerebrospinal meningitis. Here and in Camp Beauregard, the incidence of the disease was out of all proportion to that in the other camps. Just as the exaltation of virulence of the influenza virus has been favored by gross changes in the environment, the occupation, the density of, and the disease incidence in the host as a community, so also do these appear to have been factors in the development of a meningitis prevalence in the army. It was more prevalent in those camps situated in the territories where the disease was particularly endemic, but was also present in all camps. Had the meningococcus been able to assume the high degree of virulence and invasiveness possessed by the influenza virus it is reasonable to assume that a pandemic spread would have begun in one of the two or three camps where the disease was especially prevalent. It would have spread thence and have attacked those camps in which a mildly virulent meningococcus had already been causing disease. Just as in influenza the pandemic spread would have been due not to the universally distributed virus, but to the one or few which finally acquired the greatest exaltation of virulence. We see then that the followers of both theories—that of the single focus and that of an extensive distribution—can quote other infectious diseases in support of their theory, but the evidence in favor of similarity to Asiatic cholera is not complete. The disease is not similar. The mode of transmission is entirely different. The infection is chiefly of the gastro-intestinal tract, while that in influenza is chiefly respiratory. Since 1816 there have been five pandemics of Asiatic cholera, the last occurring in 1883 and all of them traceable to a primary focus in India. Frequently it was carried from India by the faithful, to Mecca and from there was readily distributed throughout Europe. In the last pandemic the disease spread throughout the old world and reached New York harbor, but was refused admission.