many certainly unfit matings would be prevented and other fit matings, that are avoided through false scruples, would be happily contracted. I propose briefly to consider what is the present state of our knowledge of the inheritance of various characteristics.
The limitations in the scope of this booklet must be made clear at the outset. As a biologist, not a physician, [underscored by hand]I shall not consider many acquired conditions which render unfit for marriage.[end underscore] Governments spend scores of thousands of dollars and establish rigid inspections to prevent the spread of the coitus disease of the horse but the Spirochete parasite that causes the corresponding disease in man and entails endless misery on hundreds of thousands of innocent children may be disseminated by anybody, and is being disseminated by scores of thousands of persons in this country, unchecled, under the protection of the "personal liberty" flag. Alas! that so little thought is had to the loss of liberty of the infected children. Marriage of persons with venereal disease is not only unfit; it is a hideous and dastardly crime; and its frequency
Fit and Unfit Matings
would justify a medical test of all males before marriage, innocent as well as guilty. Fortunately there exists for syphilis at any rate a test so simple that there can be no more objection on any sentimental ground to it than to vaccination.
Nor do I propose to consider in any detail the effects of [handwritten underscore]drugs[end underscore] on germ-plasm. The matter awaits further investigation. Meanwhile experience indicates that the marriage of alcoholists certainly and probably the users of any drug to extremes is associated with defective development of offspring and is, in so far, unfit. Also the class of cases in which, as in tuberculosis, a weakened person is quickly finished by the drain of reproductive processes bears on marriage fitness but does not belong to my topic in the narrow limits I assign it. For my topic deals rather with the result of the union of [handwritten underscore]two uninfected germ plasms[end underscore] with their [undescore]inherent[end underscore] peculiarities.
Under these limitations, then, I may say that recent developments in the study of heredity, commonly associated with the name of Mendel, enable us to formulate more precisely than hitherto the working of heredity. Three funda-