PREFACE.
The problem with which Dr.Chapple deals in this book is one of extreme gravity.

It is also one of pressing importance.

The growth of the Criminal is one of the most ominous clouds on every national horizon.

In spite of advances in criminology the rate of increase is so alarming that the "Unfit" threatens to be to the new Civilization what the Hun and Vandal were to the old.

How to deal with this dangerous class is perhaps the most serious question that faces Sociologists at this hour.
And something must be done speedily, else our civilization is in imminent peril of being swamped by the increasingly disproportionate progeny of the Criminal.
Various methods have from time to time been suggested to ward off this danger.