_Criminality in the Illegitimate._--Private and official statistical data combine to prove that in illegitimate children criminality is considerably more common than it is in the legitimate. In individual countries, and in respect of different criminal offences, the relationships are very variable; but there is not a single civilised country in which we fail to find that the average criminality-rate of illegitimate children is considerably higher than the average criminality-rate of the legitimate. We see this difference maintained, alike in respect of the number of punishable offences committed on the average by each convicted person, in respect of particular offences in the case of those who experience only one conviction, and finally in respect of the percentage of convicted offenders among the two respective classes. Not a single punishable offence can be mentioned, in respect of which we fail to find that the percentage of illegitimates convicted of that offence is larger than the percentage of legitimates so convicted. Moreover, if we compare recidivists and major offenders with other criminals, we find that the unfavourable influence of illegitimacy is especially marked in the case of the former. The conclusions drawn from the criminal statistics are confirmed by those obtained from reformatories and similar institutions; everywhere we find a higher criminality-rate among the illegitimate. One circumstance, however, which is commonly overlooked, has to be taken into account. Among those convicted of criminal offences, a certain percentage are persons of illegitimate birth (_a_); a certain percentage of all births are those of illegitimates (_b_); a certain percentage of persons who have attained the age at which they become legally liable to punishment for their actions are persons of illegitimate birth (_c_). It is not the ratio between the numbers in class (_a_) and the numbers in class (_b_) that we have to consider, but the ratio between the numbers in class (_a_) and the numbers in class (_c_). For the death-rate among illegitimate children is much higher than the death-rate of the legitimate; and the number of the illegitimate diminishes through legitimisation. Thus a much smaller proportion of young persons and of adults consists of persons of illegitimate birth than in the case of the new-born. The proper method of comparison would be to ascertain whether the percentage of illegitimate children at a certain age convicted of criminal offences or undergoing education in a reformatory is greater than the percentage of legitimate children of like age found to be undergoing the same punishment or the same education.