The world and the criminal’s friends are startled some day by a great crime, but that crime is linked on to a chain of slight, occasional, sporadic vices and offences. Sometimes we can trace out these links. Barré and Lebiez were two young French criminals who attracted attention some years ago. They were both of good family, both very intelligent, the former about to enter on a commercial life, the latter on the eve of becoming a doctor of medicine. At this point they murdered an old woman to rob her, and cut up the body to dispose of it. The crime was deliberate and carefully prepared; there was nothing romantic or obviously morbid about it, and a few days after the crime Lebiez delivered an able and eloquent lecture on Darwinism and the Church. In each of these young men there were, M. Joly observes, nine stages in the path of crime. Let us first note those of Barré:--1. His employer is obliged to dismiss him on account of misconduct with a servant girl. 2. He writes untruthful letters to his family, describing habits of work which do not exist. 3. He acquires an extravagant taste for speculation on the Stock Exchange. So far his course, though not exemplary, was one that has often enough been traversed by persons who have never reached the scaffold. 4. He speculates with the savings which two girls had entrusted to him for investment. 5. To obtain money from his father, to whom he talks of establishing himself, he forges letters. 6. He embezzles various sums of money by an aggravated form of the same process. 7. He steals a watch from a prostitute’s rooms. 8. He steals eight francs from the same. 9. He decides on the murder of the old milk-woman with whom he has had business relations, and whose savings, as he knows, are considerable. Lebiez went through the following stages:--1. His violent language to his mother is remarked. 2. He is, notwithstanding very small means, known to be living with a mistress, and he procures obscene photographs. 3. On account of irregularity he is sent away from an institution where he gave lessons. 4. He speculates on the Stock Exchange, which, being poor, he could only do by accepting profit and refusing to meet loss. 5. He steals books from his friends and sells them. 6. He several times leaves his lodgings clandestinely, without paying the rent. 7. He participates in the theft of the watch by Barré. 8. He shares the profits of the second theft. 9. They decide on the murder together. Such are the slow steps by which the occasional criminal becomes the _habitual criminal_ or the _professional criminal_. It must be remembered that the lines which separate these from each other, and both from the instinctive criminal, are often faint or imperceptible. “Natural groups,” as Mr. Galton remarks, “have nuclei but no outlines.” In the habitual criminal, who is usually unintelligent, the conservative forces of habit predominate; the professional criminal, who