Mention of the declining native birth rate in the United States had already been made (Chapter XI), with some consideration of the causes thereof. The fact needs to be called attention to in this connection as another element in the changed aspect of immigration. It is unfortunate that our census figures do not give us positive data as to the respective birth rates of the native-born and foreign-born, so that we have to rely upon estimates. All of these estimates, however, agree that there has been a marked decline in the rate of native increase, though the causes assigned vary. The population of the United States in 1810 was 1.84 times as great as in 1790, and that of 1840, 1.77 times as great as twenty years earlier. Since the immigration during all this period was relatively slight, this increase may be taken as representing a very high native birth rate. In 1900, in spite of the large element of foreign-born with a high birth rate then in the country, and the large immigration of the previous twenty years, the population of the country was only 1.52 times as large as in 1880. This must represent a tremendous fall in the native birth rate. Mr. S. G. Fisher has estimated that the rate of native increase by decades has fallen from 33.76 per cent in the decade ending 1820 to 24.53 in the decade ending 1890. Some eminent authorities, as previously mentioned, are of the opinion that at the present time the native population of parts, if not the whole, of New England is not even maintaining itself. Thus our present immigrants are being received by, and are mingling with, a people, not vigorous and prolific as in the early days, able to match the crowds of aliens with a host of native-born offspring, but weak in reproductive power, and constantly decreasing in the ability to maintain itself. In this connection it is significant that during the last intercensal decade the total foreign-born population increased 30.7 per cent, while the native-born population increased only 19.5 per cent. This fact, in connection with the high birth rate of our now large foreign-born population, puts a new face on the question of the elimination of the native stock.