The day will certainly come when the whole of mankind will be forced to check the augmentation of the human species, because there will be no further possibility of adjusting the productivity of the soil to the perpetual increase in the population. Nature must then be allowed to use her own methods or man may possibly take the task of regulation into his own hands and establish the necessary equilibrium by the application of better means than we have at our disposal to-day. But then it will be a problem for mankind as a whole, whereas now only those races have to suffer from want which no longer have the strength and daring to acquire sufficient soil to fulfil their needs. For, as things stand to-day, vast spaces still lie uncultivated all over the surface of the globe. Those spaces are only waiting for the ploughshare. And it is quite certain