Of the number of the distinctly homeless and vagrant youth in New York, it is difficult to speak with precision. We should be inclined to estimate it, after long observation, as fluctuating each year between 20,000 and 30,000. [The homeless children who come each year under the charitable efforts afterwards to be described amount to some 12,000.] But to these, as they mature, must be added, in the composition of the dangerous classes, all those who are professionally criminal, and who have homes and lodging-places. And again to these, portions of that vast and ignorant [It should be remembered that there are in this city over 60,000 persons above ten years of age who cannot write their names.] multitude, who, in prosperous times, just keep their heads above water, who are pressed down by poverty or misfortune, and who look with envy and greed at the signs of wealth and luxury all around them, while they themselves have nothing but hardship, penury, and unceasing drudgery. CHAPTER III. THE CAUSES OF CRIME. The great practical division of causes of crime may be made into preventible and non-preventible. Among the preventible, or those which can be in good part removed, may be placed ignorance, intemperance, over-crowding of population, want of work, idleness, vagrancy, the weakness of the marriage-tie, and bad legislation. Among those which cannot be entirely removed are inheritance, the effects of emigration, orphanage, accident or misfortune, the strength of the sexual and other passions, and a natural weakness of moral or mental powers. IGNORANCE. There needs hardly a word to be said in this country on the intimate connection between ignorance and crime. The precise statistical relation between them in the State of New York would seem to be this: about thirty-one per cent. of the adult criminals cannot read or write, while of the adult population at large about six (6.08) per cent. are illiterate; or nearly one-third of the crime is committed by six-hundredths of the population. In the city prisons for 1870, out of 49,423 criminals, 18,442 could not write and could barely read, or more than thirty-three per cent. [Illustration: THE FORTUNES OF A STREET WAIF. (Second Stage.)] In the Reformatories of the country, according to the statement of Dr. Bittinger before the National Congress on prison-discipline at Cincinnati, out of the average number of the inmates for 1868, of 7,963 twenty-seven per cent. were wholly illiterate. Very great criminality is, of course, possible with high education; but in the immense majority of cases a very small degree of mental training or intellectual tastes is a preventive of idleness and consequent crime and of extreme poverty. The difference between knowing how to read and not knowing will often be the line between utter poverty and a capacity for various occupations.