Dr Chapple draws attention to the undeniable fact that there is a tendency on the part of those unfit to increase at a greater ratio than the fit. The rate of increase during the past twenty years has been so great and so disproportionate as to make the cost of their maintenance become an increasingly heavier one for the individual taxpayer to bear, and to cause for this and other reasons, a considerable amount of alarm in the minds of those who have the welfare of society at heart. The Doctor believes that the cause of this proportionate rate of increase is to be found in the methods adopted largely among certain classes for the prevention of child-birth. In the conclusion of his book he states that sexual inhibition on the part of the better classes accounts for their smaller rate of increase as compared with the rate of the inferior classes. We cannot accept this conclusion without more evidence. We want to know definitely whether the natural rate of increase among the better classes is really lower than that existing among the inferior classes. That is to say, are the ranks of the defective being swelled by the influence of heredity or by some extensive force recruiting from among the ranks of the fit? Another question is this: Since the use of preventives is available to both sections alike, the Doctor accounts for the supposed natural disproportion by assuming that the better classes restrain themselves. Is he right? Using the word "restrain" in its absolute sense we beg leave for most emphatic doubt. In an enquiry such as this is, the only factor of any real importance as accounting for a diminished birth-rate, is the use of preventives. If this method is confined to the better classes, we must refuse to call them any longer our "best stock," for, if they are not producing a defective offspring, they are, as the recent Australian Birth-Rate Commission has made abundantly plain, speedily making defectives of themselves, besides being guilty of lowering the social moral tone and hardening its sensibility. We are strongly of the opinion that the diminished birth-rate does not account for the increase in the number of criminals and defectives further than that the use of preventives discloses a species of criminality.