The statistics of causes of death are available only for a certain portion of the United States, included in the so-called “death-registration area.” Unlike other civilized countries, the United States has no uniform laws for the registration of births and deaths. Moreover, the efficiency of enforcement of existing laws varies greatly in the different States. The Bureau of the Census in 1880 therefore established a “death-registration area,” which comprises “States and cities in which the registration of deaths is returned as fairly complete (at least 90 per cent. of the total), and from which transcripts of the deaths recorded under the State laws or municipal ordinances are obtained by the Bureau of the Census.” In 1880 this area included but 17 per cent. of the total population of the United States. As States and cities have passed better laws and obtained better enforcement they have been added to the registration area; the latter has increased greatly in size, but even in 1913 included only 65.1 per cent. of the population of the United States. For the remaining 34.9 per cent. of the population of the country we have no reliable statistics. This 34.9 per cent. includes the population of the greater number of the Southern States and of many Middle Western and Western States outside of certain registration cities in these States which are included in the area. No statements can be made, therefore, of the number of deaths from any cause in the United States as a whole; only an estimate can be made on the assumption that for any cause of death the same rate prevails in the remainder of the United States as in the death-registration area. PROVISIONAL BIRTH-REGISTRATION AREA The registration of births is still more incomplete in this country than is the registration of deaths. For 1910 the United States Bureau of the Census established a “provisional birth-registration area,” including the New England States, Pennsylvania, Michigan, New York City and Washington, D. C.