See e.g. Havelock Ellis, The Criminal, 4th ed., 1910, chap IV.

R.L. Dugdale, The Jukes, 4th ed., 1910. It is noteworthy that Dugdale, who wrote nearly forty years ago, was concerned to prove the influence of bad environment rather than of bad heredity. At that time the significance of heredity was scarcely yet conceived. It remains true, however, that bad heredity and bad environment constantly work together for evil.

Jörger, Archiv für Rassen-und Gesellschafts-Biologie, 1905, p. 294. Criminal families are also recorded by Aubry, La Contagion du Meutre.

Even during school life this burden is serious. Mr. Bodey, Inspector of Schools, states that the defective school child costs three times as much as the ordinary school child.

I have set forth these considerations more fully in a popular form in The Problem of the Regeneration of the Race, the first of a series of "New Tracts for the Times," issued under the auspices of the National Council of Public Morals.