The present-day high incidence and severe nature of staphylococcal infections, as conditions sui generis or as complications upon other conditions, are not new phenomena; they are old phenomena that were for some years abated by initial high efficacy of antibiotics and chemotherapeutic agents against staphylococci. Recent years have seen a recrudescence of staphylococcal infections in quantity and of quality that may be equal to, or may be worse than what obtained before the era of modern antimicrobial agents. It is easy nowadays to find statements announcing that the crack of doom is at hand because, it seems, races of staphylococci have arisen that defy the action of "antibiotics" that we have naively grown to depend upon. Awakening to the facts of biologic struggle need not be so rude; it should be expected that the inheritance of the earth will continue to be bitterly contested. There is no question that staphylococcal