laws of, resulting in science of eugenics, 293-294;
traits influenced by, 297-298;
distribution of traits, 298-300;
desirable and undesirable traits, 300-301;
illustrations of laws of, by Andalusian fowl and by guinea pigs,
307-316;
application of principles to human race, 316-322.

Hill-climbing, as exercise, 94;
for overweight, 217.

Hodge, Clifton P., fly-trap invented by, 73-74.

Home exercise, 94.

Hookworm disease, preventive measures, 75.

Hot weather, diet in, 34.

Houses, disadvantages attached to invention of, 145-147.

Housing, hygiene of, 7-14;
disadvantages of the poor regarding, 128-129.

Humidity of air, how to secure, 11-12.

Hurry, habit of, in modern life, 114;
as a promoter of indigestion, 150;
excessive use of flesh foods due to, 151.

Hygiene, individual, ideals implied by, 1;
medieval views contrasted with modern ideals, 1-2;
good, ventilation the first rule, of, 7;
mental, 105-118;
unity of, 121-126;
obstacles to, 126-135;
possibilities of, 135-143;
and civilization, 143-156;
public versus individual, 157-159;
necessity for cooperation between public and individual, 159-161;
race, 163-168;
of immediate concern to the present generation, while eugenics is
important for future generations, 167-168.

Hypochondriacs, risk of becoming, 111.

Ice-cream, comparative food value of, 33.

Ideal food proportions, 173.

Ideals, of individual hygiene, 1;
contrast afforded by medieval, 1-2;
present-day establishment of more wholesome, 2;
as to labor, 3-4;
still further improvement needed in American, 4-6.

Idleness, evils of, 91.

Impairments, unsuspected physical, 136-139.

Inactivity, necessity for periods of, 89;
rest and sleep the two great forms of, 89.

Indians, bad effects of indoor living upon, 146-147.

Indigestible foods, digestibility of so-called, 49.

Individual hygiene, public hygiene versus, 157-159;
practice of, a remedy for degenerative tendencies, 292.

Indoor living, unnatural character and evils of, 145-147.

Industrial workers, unsuspected impairments among, 137-138;
calories of food consumed daily by different classes of, 195;
powers of, lessened by use of alcohol, 238, 244.

Infections of the body, by germs, 69-75;
importance of cleanliness for avoiding, 75;
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