Armstrong’s survey has also thrown some light on the effect of the influenza on previously tubercularized individuals. In a survey of 700 individuals who had had the acute disease there were ten arrested cases of tuberculosis, or 1.4 per cent. All these had been known to be arrested cases previous to the epidemic, and in none of them did the disease appear to have been actively and permanently lighted up. Some had manifested a slight activity, but all seemed to be on the way to a rearrest of the disease. On the other hand, thirteen cases, or 2 per cent. of the 700, were found to have active tuberculosis which had hitherto been undiagnosed, and an additional eight cases, with indefinite broncho-pulmonary signs, were designated as incipient tuberculosis cases. This is to be contrasted with an incidence of active tuberculosis in the pre-epidemic examination of approximately one per cent. These figures would indicate an increase in tuberculosis incidence. How may this be explained? The accuracy of these results will depend on how the 700 cases were selected. If, for example, individuals who feared tuberculosis because of known exposure, requested examination, the results might be influenced by their inclusion. It has long been known that individuals with measles will not react to tuberculin tests, even though they have been positive before developing the measles, and though they will become positive again after recovery. The same may be said of vaccination. Individuals vaccinated against smallpox, who have measles, and are during their illness revaccinated, will not show an immediate reaction. The test will remain entirely negative, while after recovery, the immediate reaction may be obtained. Normally, it will appear in 95 per cent. of cases, while among those with measles the phenomenon remains absent in 90 per cent. The same phenomenon is present in certain other acute illnesses, particularly scarlet fever. It has been variously explained. von Pirquet, who was the first to observe it in measles, believed that the acute disease created a temporary inability to produce antibodies, and therefore designated the condition by the name “anergie.” The same phenomenon of anergie has been found recently to hold in the case of influenza. Debré and Jacquet, Lereboullet, Bloomfield and Mateer, as well as Berliner and Schiffer, have brought forth abundant evidence to this effect, following the 1918 pandemic. It has also been shown by Cayrel and others that there is a diminution of typhoid agglutinins in the serum of influenza patients vaccinated against typhoid. The agglutinin titer again increases after recovery. It is true that the agglutinin titer is not a measure of immunity, but it is frequently used as such and serves to give us some information on the subject. If, then, influenza is an anergic disease, a “maladie anergisante,” we have a theoretical explanation of the increase in severity of tuberculosis following the acute infection. We have long