After having shown in the first chapter of his work, “Verbrechen und Prostitution”, [260] the relation between criminality and prostitution, and the increase of the two at the same time, the author gives, in his second chapter, a short exposition of the doctrine of criminal anthropology, and in the third chapter he takes up the doctrine of the social environment. Here he treats first of the encouragement of prostitution and crime by the marriage restrictions. Marriages increase or decrease as economic conditions grow better or worse. So, for example, in Prussia there were, from 1866 to 1870, 1605 marriages to 100,000 of the population; this number rose to 1896 in the period of prosperity between the years 1870 and 1875, only to fall, in 1888, to 1624. In bad times the number of illegitimate births makes a consequent increase. It is very comprehensible that natural children furnish a greater number of criminals than legitimate children, since they have more difficulty in enduring the combat of life than the others. Then he sets forth as a cause of crime the influence of domestic relations. When the parents belong already to the class of criminals, it is almost inevitable that their children should fall into the hands of justice while still young. And the present system of production brings it about that the education of the children of the proletariat is almost nil, since it obliges the father, and very often the mother also, to work away from home during a great part of the day and often of the night. The situation is still more unfavorable for the children who have lost their parents when they were still quite young. Starke says that about 57% of the legitimate children among the juvenile prisoners in Plötzensee were orphans or had been abandoned by their parents.