It is common knowledge that during the period 1875–1939 a very drastic fall in fertility occurred in most of the civilised countries throughout the world. This fall was particularly marked in Germany and some of the countries of North-western Europe, such as Norway, Sweden, England, Scotland, etc. The causes which have produced such important changes in the rates of reproduction in these communities are doubtless complex, and are difficult to investigate directly. It is therefore all the more important that our knowledge of the actual course of events should be as complete as possible. A major social change, such as this fall in fertility over large and important regions of the earth, can be fruitfully studied from many points of view. The present communication concentrates on one particular aspect, namely the influence of different types of geographical regions with their various social environments, and confines itself to the experiences of Scotland.