These exponents of the school which contends that plague epidemics are little affected by rat-excluding, rat-destroying and rat-proofing efforts, believe that the waning and disappearance of epidemic plague in a given place depend in chief part upon the exhaustion of susceptible material among the rodent population. However appealing this argument may be, it is impossible for its exponents to duplicate American results with equal results in the cities of China, India, Java and elsewhere, where governmental control and adequate financial ability to carry out campaigns have been lacking, from one cause or another. Wherever our methods have been followed, at home and in the insular possessions of the United States, we have terminated human epidemics of plague and have apparently put an end to rat plague in comparatively short campaigns. So long as this discrepancy in results continues we shall favor the American plan. When we review the work and results of Blue and his fellows of the United States Health Service and the officers of the Bureau of Health of the Philippine Islands, we find little reason for us to favor a change to the expectant plan of waiting for an epidemic to run its course. While speaking of the Philippine Islands, the admirable work of Strong in Manila, covering years of study of the immunity problem, and his dangerous and highly valuable work as a member of the Commission which studied the Manchurian epidemic of pneumonic plague in 1911, must be mentioned. Some years ago I called attention to the fact that few, if any, American cities were prepared to meet an outbreak of plague with an adequate supply of antipest serum and that the preparation of antiplague serum was a neglected or overlooked branch of serum manufacture in the United States. Since that time, in the midst of a plague epidemic in Manila, where, for a time, the supply of locally prepared (Bureau of Science) serum threatened to become exhausted, I looked into the possibilities of getting a supply elsewhere and found that, to do so, in anything like a reasonable length of time, was impossible. Fortunately the threatened serum famine did not occur, the local supply in Manila proving adequate, although for a few weeks we were obliged to make use of a stock of Japanese serum which had been on hand for several years. Since the warning of some years ago, at which time the plague danger was an anticipated one, bubonic plague has actually appeared in the United States (New Orleans), the cases being sufficiently numerous to cause grave concern and to call forth the utmost repressive efforts of the authorities. The possibility of plague appearance in the coast cities of the United States, at any time, cannot be disregarded and provision for the treatment of human cases, as well as repressive (antirat) measures, is imperative. Antiplague serum is not producible upon a few hours' notice, nor is it manufactured in the United States. In view of present war conditions