Esquirol, quoted by Bucknill and Tuke, p. 58, says:—­“Of all diseases Insanity is the most hereditary.”

Bucknill and Tuke, p. 647, say:—­

“Of marriage it may be said that the celibacy of the insane is the prophylaxis of Insanity in the race, and although a well chosen mate and a happy marriage may sometimes postpone or even prevent the development of insanity in the individual, still no medical man, having regard to the health of the community, or even of that of the family, can possibly feel himself justified in recommending the marriage of any person of either sex in whom the insane diathesis is well marked.”

Again (pp. 647 and 648) “It is thus that the seeds of mental diseases and of moral evils are sown broadcast through the land; and other new defects and diseases are multiplied and varied with imbecilities, and idiocies, and suicidal and other propensities and dispositions, leading to all manner of vice and crime.  The marriage of hereditary lunatics is a veritable Pandora’s box of physical and moral evil.”

The least fit, then, are the most fertile, and the most fertile are subject to the common law of heredity, and the defects are transmitted to their offspring, often accentuated by the intermarriage which their circumstances favour or even necessitate.

But this is not all.  The least fit have the worst environment, and in the worst possible surroundings the progeny of the unfit multiply and develop.  They are born into conditions, well described by Dr. Alice Vicery, in a paper on “The food supplies of the next generation.”  “Conditions in which the food, warmth, and clothing which are necessary for the mere maintenance of the functions of the body in their normal state, cannot be obtained; in which men, women, and children are forced to crowd into dens wherein decency is abolished, and the most ordinary conditions of healthful existence are impossible of attainment; in which the pleasures within reach are reduced to bestiality and drunkenness; in which the pains accumulate at compound interest in the shape of starvation, disease, stunted development, and moral degradation in which the prospect of even steady and honest industry is a life of unsuccessful battling with hunger, rounded by a pauper’s grave.”

What possible hope can there be for the progeny of defectives born with vicious, criminal, drunken or pauper tendencies, into an environment whose whole influence from infancy to maturity tends to accentuate and develop these inherited defects?

In this pitiable stratum of human society, vice and misery, as checks to increase, reign supreme, but as no other check exists, fertility is at its maximum, and keeps close up on the heels of the positive checks.