Impotence—absolute, 198; alcohol in, 182; atonic, 198; of copulation, male, 192; female, 206; diabetic, 193; drugs in, 181, 184; etiology, male, 169; female, 182; fear in, 181; by gonorrhoea, 181, 208; idiopathic, 182; libido in, 187; female, 208; organic, 192; by obesitas, 193; by over-estimation, 197; by over-excitation, 196; paralytic, 193; partial, 198; pathology, male, 185; female, 205; psychic, 194; relative, 195; by shocks, 197; symptomatic, 181, 193; temporary, 195; transitory, 194; of voluptas, 186; female, 206 Impotencies, four kinds, 186 Impregnation—process of, 67; place of, 83 Impulse—of attraction of mates, 125; of conjugation, 125; contrectation, 104, 109; contrectation in eunuchs, 186; of detumescence, 104, 109; of permanent mating, 125 Impurity—through chance acquaintances, 333; pleasure-seeking, 333; vanity, 333 Incest, 250; castration in, 251; immorality of, 368 Incontinence, male, 401 Incontinentia urinae, 205, 353 Index of sentimental love, 136 Individual allotments, 387 Individuality in love, 136 Infant, helplessness of, 126 Infatuation, 134, 138 Infusorium, 113 Inheritance in female line, 386 Inhibition, centre of—male, 40; female, 55; of libido, 97 Instinct—children’s sex, 106; definition of, 102, 104, 326; of propagation, 109, 112, 125; of reproduction in altruism, 12; of voluptas, 185; of female purity, 389 Instincts perfective, 140 Instruction in sex, 315 Intellect in libido, 93 Intelligence, in universe, 14; survival value of, 152 Intensity of libido, 95 Intercourse—in confinement, 356; frequency, 351; ideal, 222, 239, 244; in lactation, 356; in partial frigidity, 357; positions in, 350; in pregnancy, 355 Intermarriage, 385 Intermenstrual conception, 349, 358 Internal messages, 106, 108 Interval between confinements, 358 Intoxication—impurity by, 332; of work, 374 Invention of bow, 385 Inverts, mode of intercourse of, 288 Ireland, yonism in, 4 Israel, 371; sex worship in, 5 Jacobi, 165 Jacobs, 242 Jaeger, 98 Jagadis Chandra Bose, 380 James, 7 Janet, 133 Jealousy, 157; in children, 106; in homosexuality, 286; and rival, 157, 159 Jews, circumcision in, 16 Job, 275, 371 Joy, nature of, 139 Juda, 4 Judaism and Christianity, 371 Judeo-Christian creed, 370 Justice—social, 369, 371; retributory, 371 Justinus, 5 Juvenal, 279 Kant, 142, 146, 151, 155, 384, 389 Karsch, 311 Katabolism, 366 Katherine of Russia, 220 Keimepithel, 83 Key of love, 132 Key, Ellen, 139, 180 Kidney, primitive, 20 Kiernan, 264, 289, 294, 320 Kisch, 87, 234 Kiss, anal, 255 Kiss-literature, 247 Kissing, origin of, 96 Klein, 85