Progress in Birth Control.

Population growth is not a new phenomenon, what is new is the rate of growth. In pre-scientific times populations expanded by only a few ,tenths of I per cent annually, excluding slaves and then mainly in their "golden ages." This rate amounted to perhaps 15 to 25 per cent per generation. The family grouping is the link through which reproduction and the nurture of children are related to other features of the social system. Looked at in one way, a society is an aggregation of families with a language, an economy, a religion, or a political system in common-often it is all of these at once and more.