=The Relative Importance of Heredity and Environment in This Field Uncertain.--=The whole question of crime and delinquency is a highly complex one. Here, perhaps, more than in any other phase of race betterment we find the greatest difficulty in separating the effects of hereditary predisposition from the results of unfavorable environment. While there is no longer a reasonable doubt about such nervous disorders as epilepsy, feeble-mindedness and certain forms of insanity being rooted largely in ancestral taints, the degree to which crime or delinquency is based on heredity is far more questionable. Every student of genetics knows that we may have dwarf plants because the constitution of the germ is of a nature to produce only such individuals, or we may have dwarfed plants because of adverse conditions of soil and lack of an opportunity to climb or rise to their full capacity. Bateson pertinently remarks, "The stick will not make the dwarf pea climb, though without it the tall can never rise. Education, sanitation, and the rest are but the giving or withholding of opportunity." The important sociological question for us to determine is which of these lowly peas of the human family are really dwarfs and which are dwarfed simply because the stick of opportunity on which to climb is lacking. Beyond doubt a considerable portion of crime and degeneracy is due in large measure to innate inclination, but with just as little doubt much is the effect mainly of vicious habits acquired through an unwholesome environment. A normal appetite or impulse may be given a pathological trend by bad influences. And one has to reckon, moreover, with degrees of hereditary aptitude to crime. Just what is the measure of normality? To what extent by developing to their highest point certain inhibitive or opposing tendencies, can we counteract certain inherent proclivities for wrong-doing? By what means shall we sift the congenital defectives from the victims of suppressed opportunities? These and kindred questions confront us at the very outset of our studies of crime and delinquency. It is obvious that although we may institute the strictest elimination of the socially unfit, unless we can provide a wholesome environment for the fit, lapses into unfitness are sure to recur.