We have now to answer the question as to the eugenical application of the laws of inheritance of defects. First, it may be pointed out that traits due to the absence of a determiner are characterized by their usual sparseness in the pedigree, especially when the parents are normal; by the fact that they frequently appear where cousin marriages abound, because cousins tend to carry the same defects in their germ plasm, though normal themselves; by the fact that two affected parents have exclusively normal children, while two normal parents who belong to the same strain, or who both belong to strains containing the same defect, have some (about 25 per cent) defective children. But a defective married to a pure normal will have no defective offspring. The clear eugenical rule is then this: Let abnormals marry normals without trace of the defect, and let their normal offspring marry in turn into strong strains; thus the defect may never appear again. Normals from the defective strain may marry normals of normal ancestry, but must particularly avoid consanguineous marriages. The sociological conclusion is: Prevent the feeble-minded, drunkards, paupers, sex-offenders, and criminalistic from marrying their like or cousins or any person belonging to a neuropathic strain. Practically it might be well to segregate such persons during the reproductive period for one generation. Then the crop of defectives will be reduced to practically nothing. 3. Inheritance of Acquired Nature: Tradition[77]