n, 140.

Coefficient of variability, 62, 63.
human, 69.

Color blindness, heredity of, 142.

Connecticut, vasectomy statute of, 220-222.

Conservation of human protoplasm, 136.

Correlation, 103, 104.
coefficient of, 110, 111.
social status and birth rate, 116-123.

Cousin marriage, regulation of, 154, 155.

Criminality, and order of birth, 125, 126.
increase in, 29.

Darwin, pedigree of, 181, 183.
quoted, 6, 184.

Data, need for and collection of, 192.

Davenport, quoted, 192-195.

Deaf, United States census of, 34.

Deaf and dumb, United States census of, 34.

Deaf-mutism, heredity of, 143.

Deaf-mutism, pedigree of, 160, 167.

Defect, and order of birth, 123-126.

Defectives, number of, in Great Britain, 31.
United States census of, 34.

Dependents, United States census of, 34.

Determiners, absence of, 143.
in germ, 54.
in Mendelian heredity, 88-95.

Development of the individual, 51.
as a form of reaction, 52, 53.

_Die Familie Zero_, 184-187.

Differential fertility, 113-121.

Dominance, in Mendelian heredity, 84.
irregular and incomplete, 87.

Dominant characteristics, 85.

Drapers' Company, 14.

Dugdale, account of "Jukes" family, 182-184.
quoted, 236, 237.

Education, 20, 71.
heritable effects of, 200.

Edwards, Jonathan, descendants of, 187, 188.

Elderton, quoted, 209-211.

Employer's liability laws, effects of, 211.

England, falling birth rate in, 122.
number of defectives in, 31, 32.

Environment, effects of, 197-207.

Eugenics, aims of, 5, 42-45, 114, 123.
as a factor in religion, 239, 240.
definition of, 3.
encouragement of ideals of, 234-240.
history of, 10-13.
objections to, 191.
practice of, 215-234.
program of, 189-240.

Eugenics Committee of American Breeders' Association, 15, 196.

Eugenics Education Society, 14.

Eugenics Laboratory, 14.

Eugenics Record Office, 15.

_Eugenics Review_, 14.

External conditions, effects of, 199-203.

Eye color, heredity of, 140, 142, 143.

Fabian Society, 122.

_Familie Zero_, 184-187.

Family histories. _See_ Pedigrees.

Feeble-minded, in Great Britain, 32.
in United States, 34.

Feeble-mindedness, pedigree of, 162-169.

Fellows of the Royal Society, mental heredity in, 145, 146.

Fertility, and social status,