In a closed country, producing all its own necessities of life and incapable of expansion, a high birth-rate would eventually increase the struggle for existence and would lead to overpopulation, always provided that, firstly, the high birth-rate is accompanied by a low death-rate, and secondly, that the high birth-rate is maintained. For example, although a birth-rate was high, a population would not increase in numbers if the death-rate was equally high. Therefore, a high birth-rate does not of necessity imply that population will be increased or that overpopulation will occur. Again, if the birth-rate fell as the population increased, the danger of overpopulation would be avoided without the aid of a high death-rate. For a moment, however, let us assume that the Malthusian premise is correct, that a high birth-rate has led to overpopulation, and that the struggle for existence has therefore increased. Then obviously the death-rate would rise; the effect of the high birth-rate would be neutralised; and beyond a certain point neither the population nor the struggle for existence could be further increased. On these grounds Neo-Malthusians argue that birth-control is necessary precisely to obviate that cruel device whereby Nature strives to restore the balance upset by a reckless increase of births; and that the only alternative to frequent and premature deaths is regulation of the source of life. As a corollary to this proposition they claim that, if the death-rate be reduced, a country is bound to become overpopulated unless the births are artificially controlled. Fortunately it is possible to test the truth of this corollary, because certain definite observations on this very point have been recorded. These observations do not support the argument of birth controllers. (a) _In the Suez Canal Zone_ In the Suez Canal Zone there was a high death-rate chiefly owing to fever. According to Malthus it would have been a great mistake to lower this death-rate, because, if social conditions were improved, the population would rapidly increase and exceed the resources of the country. Now, in fact, the social conditions were improved, the death-rate was lowered, and the subsequent events, utterly refuting the above contention, are thus noted by Dr. Halford Ross, who was medical officer in that region: