Definition of a parasite, 1; examples among various animals, 2; Parasitism, 3; effect on the parasite, 4; how a harmless kind may become harmful, 5; immunity, 6; Diseases caused by parasites, 7; ancient and modern views, 7; Infectious and contagious diseases, 8; examples, 9; importance of distinguishing, 9; Effect of the parasite on the host, 9; microbes everywhere, 10; importance of size, 11; numbers, 11; location, 11; mechanical injury, 12; morphological injury, 13; physiological effect, 13; the point of view, 14.

Bacteria, 15; border line between plants and animals, 15; most bacteria not harmful, 15; a few cause disease, 15; how they multiply, 15; parasitic and non-parasitic kinds, 17; how a kind normally harmless may become harmful, 18; effect of the bacteria on the host, 18; methods of dissemination, 18; Protozoa, 19; Amoeba, 19; its lack of special organs, 19; where it lives, 19; growth and reproduction, 19; Classes of Protozoa, 20; the amoeba-like forms, 20; the flagellate forms, 20; importance of these, 21; the ciliated forms, 22; the Sporozoa or spore-forming kinds, 22; these most important, 23; abundance, 23; adaptability, 23; common characters, 24; ability to resist unfavorable conditions, 24.

Ticks, 26; general characters, 27; mouth-parts, 27; habits, 27; life-history, 27; Ticks and disease, 28; Texas fever, 28; its occurrence in the north, 28; carried by a tick, 29; loss and methods of control, 31; other diseases of cattle carried by ticks, 31; Rocky Mountain spotted fever, 32; its occurrence, 32; probably caused by parasites, 32; relation of ticks to this disease, 33; Relapsing Fever, 33; its occurrence, 34; transmitted by ticks, 34; Mites, 35; Face-mites, 35; Itch-mites, 36; Harvest-mites, 37.

Numbers, 40; importance, 41; losses caused by insects, 41; loss of life, 42; The flies, 43; horse-flies, 43; stable-flies, 44; surra, 45; nagana, 45; black-flies, 46; punkies, 46; screw-worm flies, 47; blow-flies, 48; flesh-flies, 48; fly larvÆ in intestinal canal, 49; bot-flies, 50; Fleas, 52; jigger-flea, 53; Bedbugs, 54; Lice, 54; How insects may carry disease, 55; in a mechanical way, 55; as one of the necessary hosts of the parasite, 56.

The old attitude toward the house-fly, 57; its present standing, 58; reasons for the change, 58; Structure, 59; head and mouth-parts, 60; thorax and wings, 61; feet, 62; How they carry bacteria, 62; Life-history, 63; eggs, 63; ordinarily laid in manure, 63; other places, 63; habits of the larvÆ, 64; habits of the adults, 64; places they visit, 65; Flies and typhoid, 65; patients carrying the germs before and after they have had the disease, 65; how the flies get these on their body and distribute them, 66; results of some observations and experiments, 66; Flies and other diseases, 68; flies and cholera, 68; flies and tuberculosis, 69; possibility of their carrying other diseases, 70; Fighting flies, 71; screens not sufficient, 71; the larger problem, 71; the manure pile, 72; outdoor privies, 72; garbage can, 72; coÖperation necessary, 72; city ordinances, 73; an expert's opinion of the house-fly, 73; Other flies, 75; habits of several much the same but do not enter house as much, 75; the small house-fly, 75; stable-flies, 75; these may spread disease, 75.

Numbers, 76; interest and importance, 76; eggs, 77; always in water, 77; time of hatching, 77; LarvÆ, 78; live only in water, 78; head and mouth-parts of larvÆ, 78; what they feed on, 78; breathing apparatus, 79; growth of the larvÆ, 80; PupÆ, 80; active but takes no food, 80; breathing tubes, 80; how the adult issues, 81; The Adult, 81; male and female, 81; how mosquitoes "sing" and how the song is heard, 82; the palpi, 82; The Mouth-parts, 83; needles for piercing, 83; How the mosquito bites, 84; secretion from the salivary gland, 84; why males cannot bite, 84; blood not necessary for either sex, 84; The Thorax, 85; the legs, 85; the wings, 85; the balancers, 85; the breathing pores, 86; The abdomen, 86; The digestive system, 86; The salivary glands, 87; their importance, 87; effects of a mosquito bite, 87; probable function of the saliva, 88; How mosquitoes breathe, 89; Blood, 90; in body cavity, 90; heart, 90; Classification, 91; Anopheles, 91; distinguishing characters, 92; eggs, 92; where the larvÆ are found, 93; Yellow fever mosquito, 94; its importance, 94; the adult, 95; habits, 95; habits of the larvÆ, 95; Other species, 96; some in fresh water, others in brackish water, 96; Natural enemies of mosquitoes, 97; how natural enemies of mosquitoes control their numbers, 98; mosquitoes in Hawaii, 98; Enemies of the adults, 99; Enemies of the larvÆ and pupÆ, 100; Fighting mosquitoes, 101; fighting the adult, 102; Fighting the larvÆ, 103; domestic or local species, 104; draining and treating with oil, 104; combatting salt-marsh species by draining, 105; by minnows or oil, 105.

Early reference to malaria, 106; its general distribution, 106; theories in regard to its cause, 107; insects early suspected, 107; The parasite that causes malaria, 108; studies of the parasite, 108; Life-history in human host, 109; its effect on the host, 110; the search for the sexual generation, 111; The parasite in the mosquito, 112; review of whole life-history, 115; malaria transmitted only by mosquitoes, 115; Summary, 117; experimental proof, 118.

A disease of tropical or semi-tropical countries, 120; outbreaks in the United States, 120; parasite that causes the disease not known, 121; formerly regarded as a contagious disease, 122; The yellow fever commission, 123; Dr. Finlay's claim, 124; experiments made by the commission, 125; summary of results, 129; what it means, 130; results in Havana, 131; the fight in New Orleans, 132; In the Panama canal zone, 135; in Rio de Janeiro, 136; claims of the French commission, 138; habits of stegomyia, 139; breeding habits, 139; possible results of war against the mosquitoes, 139; Danger of this disease in the Pacific Islands, 140.

Great scourges, 142; the "black death," 142; old conditions and new, 143; How plague was controlled in San Francisco, 143; Indian Plague commission, 144; Dr. Simond's claim, 145; The advisory committee and the new commission, 146; Results of Dr. Verjbitski's experiments, 147; Results of various investigations, 150; structure and habits of fleas, 151; feeding habits, 152; Common species of fleas, 153; Ground squirrels and plague, 155; squirrel fleas, 156; Remedies for fleas, 157; cats and dogs, 159.

Sleeping Sickness, 161; its occurrence in Africa, 161; caused by a Protozoan parasite, 162; the tsetse-fly, 163; Elephantiasis, 164; caused by parasitic worms, 164; their development, 165; how they are transferred to man, 165; effect on the patient, 166; Dengue, 168; other names, 168; probably transmitted by mosquitoes, 170; Mediterranean fever, 171; cause, 171; may be conveyed by mosquitoes, 171; Leprosy, 171; caused by a bacteria parasite, 171; possibilities of flies, mosquitoes and other insects transmitting the disease, 172; Kala-azar, 173; transmitted by the bedbug, 173; Oriental sore, 174; the parasite may be carried by insects, 174.

Parasites and parasitism, 175; Protozoa, 176; Bacteria, 177; Insects and disease, 178; Mosquitoes—systematic and general, 179; Mosquito anatomy, 182; Mosquitoes—life-history and habits, 183; Mosquito fighting, 183; Mosquitoes and disease, 185; Malaria, 186; Yellow fever, 189; Dengue, 192; Filarial diseases and elephantiasis, 193; Leprosy, 193; Plague, 194; Fleas, 198; Typhoid fever, 199; House-flies—anatomy, life-history, habits, 200; House-flies and typhoid, 202; House-fly and various diseases, 203; Human myiasis, 207; Stomoxys and other flies, 208; tsetse-flies, 209; Trypanosomes and Trypanosomiasis, 210; Sleeping sickness, 211; Rocky mountain fever and ticks, 212; Ticks and various diseases, 213; Kala-azar and bedbugs, 216; Text or reference books, 216; Miscellaneous articles, 218.