in, 122.
university of, 14.

Man's place in Nature, 6, 7.

Marriage, antecedents to, 238, 239.
restrictions in, 228-232.

Mediocrity, 61.

Mendel, Gregor, 83, 84.

Mendelian formula of heredity, 80-102.

Mendelism and eugenic practice, 97, 233.

Mendel's law, and unit characters, 95-99.
characteristics inherited according to, 98, 99.
human, 142, 143.
complications of, 100.
present limitations of, 100-102.

Mental ability, pedigrees of, 176-181.

Mental defect, heredity of, 147, 160, 165, 162-169.

Mental traits, heredity of, 143-147.

Models, illustrating variability and variation, 59, 63-64.

Murders, number of, 30.

Mutation, 63-66.

National Association of British and Irish Millers, 133.

Natural selection, 21-23, 45.

Nettleship, pedigree of night blindness, 158-163.

Night blindness, heredity of, 143.
pedigrees of, 157, 158, 161, 163.

Normal frequency curve, 56-60.

Nurture, 17, 76.

Oedema, pedigree of angio-neurotic, 168-170.

Ohio Institution for the Feeble-Minded, superintendent quoted, 33.

Oneida community, 10.

Ontogeny, 51.

Ooephorectomy (ooephorotomy), 218-222.

Order of birth and pathological defect, 123-126.

Oxford, mental heredity in graduates of, 146, 147.

Paupers, United States census of, 34.

Pearson, Karl, 14, 27, 36.
heredity in school children, 143, 144.
quoted, 127-130, 216-218, 225-227.

Pedigrees of ability, 176-181.

Pedigrees of angio-neurotic oedema, 168, 170.
of brachydactylism, 150-153.
of cataract, 157, 159.
of deaf-mutism, 160, 167.
of feeble-mindedness, 162-169.
of Huntington's chorea, 160, 165.
of infertility, 174, 175.
of lobster claw or split hand, 155-157.
of night blindness, 157-163.
of polydactylism, 155, 156.
of tuberculosis, 168-171.

Plato, 3, 9.

Ploetz, Dr. Alfred, 230.

Poellman, family described by, 181.

Polydactylism, heredity of, 142.
pedigree of, 155, 156.

Population, of Europe and North America, 25, 26.

Practice of Eugenics, 192-240.

Prisoners, number of, in United States, 29, 30.

Probability, law of, 56-59.

Pure bred, 97.

Pure line, 67, 72.

Recessive characteristics, 85.

Regression, 105-108.

Regression line, 106, 107.

Rentoul, statistics of defectives, 31.

Rentoul's operation, 218-222.

Research, i