When a crop of offences of a similar kind startles a district there may be a common cause found if it is sought for; and when the offences cease their cessation may be found to have some relation to that cause; but the arrest and imprisonment of one here and there as examples have as little relationship to the cessation of offences as prayer had in the stopping of an epidemic of cholera. In the one case you have to break up the association of offenders and destroy their spirit; in the other you have to attend to your drains and your sanitation. The punishment and the prayer in either case may assist in so far as they direct attention to the need for right action. How then do these outbreaks originate, and what causes them to cease? In the first place, they are not the work of professional thieves, though these take advantage of them. They begin in horseplay among the lads at the street corner. None of them may be abnormally mischievous or wicked, but a crowd has a spirit of its own which is different from that of its members. Everybody has seen dignified citizens under the excitement of, say, an election, when they got the news that the country had been saved in the way they desired, behaving in a sufficiently ridiculous manner and inciting others to a like behaviour. If they had received the news when at home it would at most have caused a smile, but in a crowd one has stirred the other to do and say things that neither would ordinarily do or say. An orator may sway a crowd and utterly fail to move the members of it if he spoke to them individually. The lads at the corner will do things when they are together that none of them would think of doing if he were alone. Not only does each incite the other, but all incite each one to action. The horseplay is extended and indulged in by them at the expense of passers-by, and to their annoyance. If it stops there no noise is heard about "Hooliganism"; but if the lads, letting themselves loose, go further and injure a respectable citizen there is complaint. The culprit is at first frightened, but having done the thing he tries to make the most of it, especially if he sees his companions rather admire his temerity. He boasts of his daring and excites emulation. One tries to outdo another; other "corners" hear about and imitate the desperadoes; the newspapers take the matter up; and the place is in a state of terror. There is reason for the terror, too; for in the process unoffending and peaceful citizens have suffered serious injury. The professional criminal, who is quick to take advantage of any chance, hangs on to the tails of the foolish lads, and under cover of their depredations helps himself to what he can get. Anything that gathers a crowd helps him, but he knows better than to commit assaults of this purposeless kind himself. He has no objection to rob the assaulted or the threatened and terrorised parties, however, provided he can conceal himself. If he can get any of the lads who began