It is of great interest to the British reader to look at the question briefly from his point of view. At the present time our wheat production is no more than one-eighth of our needs, and in twenty-five years, when the supply from the United States will probably have ceased, we shall require 40,000,000 quarters of wheat per annum. Yet already, in time of peace, careful observers such as the Rt. Hon. Charles Booth and Mr. Seebohm Rowntree declare that thirty per cent. of our own population are living on the verge of starvation. Our available supply of food of all kinds at any moment would last us about three weeks. How many of us realise what a war would mean for this country? Yet in the face of facts such as these, the majority of those who attempt to guide public opinion are urging us to increase our birth-rate and still pin their faith to quantity rather than quality of population as our great need. =The theory of Malthus.=--The reader who is interested in general biology will realise, of course, that we are here back to the great argument of Malthus, advanced in 1798 in his _Essay on the Principle of Population_. Malthus was a great and sincere thinker, a high and true moralist, and the people who have a vague notion that his name has some connection with immoral principles of any kind have no acquaintance with the subject. It is of the deepest interest for the history of thought to know that it was the work of Malthus which suggested, independently, both to Charles Darwin and to Dr. Alfred Russel Wallace, that principle of natural selection, the survival of the fittest and their choice for parenthood, the discovery of which constituted one of the great epochs in the history of human knowledge, and which is the cardinal principle underlying the whole modern conception of eugenics or race-culture.