The congenital character and hereditary transmission of criminal tendencies in these individuals fully justify the words of Quetelet, that ``moral diseases are like physical diseases: they are contagious, or epidemic, or hereditary. Vice is transmitted in some families in the same way as scrofula or consumption. The greater number of crimes come from a comparatively few families, which need a special supervision, an isolation like that which we impose on sick persons suspected of carrying the germs of infection.'' So Aristotle speaks of a man who, being accused of beating his father, answered: ``My father beat my grandfather, who used to beat his father cruelly; and you see my son--before he is grown up he will fly into passions and beat me.'' And Plutarch added to this: ``The sons of vicious and corrupt men reproduce the very nature of their parents.'' This is the explanation of Plato's idea, who, ``admitting the principle that children ought not to suffer for the crimes of their parents, yet, putting the case of a father, a grandfather, and a great-grandfather who had been condemned to death, proposed that their descendants should be banished, as belonging to an incorrigible family.'' Carrara called this a mistaken idea, but it seems to us to be substantially just. It may be remembered that when De Metz in 1839 founded his agricultural penal colony at Metray, once celebrated but now in decay (for the whole success of these foundations depends on the exceptional psychological qualities of their governors), out of 4,454 children, 871, or 20 per cent., were the children of convicts. We quite agree with Crofton's proposal to <p 252>place the children of convicts in industrial schools or houses of correction. A special establishment for the perpetual or indefinite seclusion of incorrigible criminals has been proposed or approved in Italy by Lombroso, Curcio, Barini, Doria, Tamassia, Garofalo, Carelli; in France by Despine, Labatiste, Tissot, Leveill<e'>; in Russia by Minzloff; in England by May; in Germany by Kraepelin and Lilienthal; in Austria by Wahlberg; in Switzerland by Guillaume; in America by Wines and Wayland; in Holland by Van Hamel; in Portugal by Lucas; &c. But I believe that, in order to establish the fact of incorrigibility, the number of relapses should vary in regard to different criminals and crimes. Thus, for instance, in the case of murders, especially by born criminals, the first crime should lead to an order for imprisonment for life. In the case of less serious crimes, such as rape, theft, wounding, swindling, &c., from two to four relapses should be necessary before the habitual criminal is sentenced to such imprisonment. These ideas are approximately carried out, especially in the countries which, having made no great advance in the criminal sciences, meet with less of pedantic opposition to practical reforms.