of about 150,000 mental defectives which this country supports. The country owes it to itself as a matter of self-preservation that every imbecile of reproductive age should be held in such restraint that reproduction is out of the question. If this proves to be impracticable then sterilization is necessary - where the life of the state is threatened extreme measures may and must be taken.
Manic-depressivc insanity seems likewise due to a defect, in any case it is especially apt to occur in families in which both parental strains show the disease. I give a few cases. (A 2, 3.)
While, on account of the complexity of nervous diseases, all of the children even of two neurotic parents are not always neurotic, the chances of this result are much increased when the parents are related. This is illustrated by the family described by Karpas. Here all children are nervously defective. (A 4.)
The case of partial hermaphroditism is peculiar because it affects usually only the male sex. The inhibitor of complete sex differentiation seem to be dominant in the male - the embryo-
Fit and Unfit Matings
logically more advanced sex - though it may fail to activate in and is indeed irrelevant to the female sex. (A 6.) Since the abnormality is necessarily revealed only by the male sex the condition of the female is no test of her germ-plasm in respect to this characteristic. As a matter of fact the normal mother may easily represent the defective strain. A normal male belonging to the defective strain is usually without a trace of the inhibitor, yet a few cases are known of an apparently normal person with an inactive "inhibitor" having, by a normal consort, abnormal sons. But, in general, the marriage of females belonging to hermaphrodite (hypospadic) strains is unfit, while normal males of such strains may marry females from normal strains.
The case of Huntington's chorea is a striking one of inheritance of disease. This is a form of chorea that leads to dementia and death. A. S. Hamilton has worked up the pedigree of many cases. (A 1.) The mating of two parents with chorea is obviously highly unfit and should not be permitted.