ILLUSTRATIONS
| An artificial lake, nearly dry and partly filled with rubbish, has become a breeding-ground for dangerous mosquitoes | [Frontispiece] | |
| PAGE | ||
| [Fig. 1.] | A lamprey | 2 |
| [Fig. 2.] | Sacculina | 2 |
| [Fig. 3.] | Trichina spiralis | 2 |
| [Fig. 4.] | An external parasite, a bird-louse (Lipeurus ferox) | 3 |
| [Fig. 5.] | An internal parasite, a tachina fly (Blepharipeza adusta) | 3 |
| [Fig. 6.] | Work of an internal parasite, puss-moth larva parasitized by a small ichneumon fly | 3 |
| [Fig. 7.] | Typhoid fever bacilli | 20 |
| [Fig. 8.] | Amœba | 20 |
| [Fig. 9.] | Euglina virdis | 21 |
| [Fig. 10.] | Spirocheta duttoni | 21 |
| [Fig. 11.] | Paramœcium | 22 |
| [Fig. 12.] | Vorticella | 22 |
| [Fig. 13.] | Pathogenic protozoa; a group of intestinal parasites | 22 |
| [Fig. 14.] | Castor-bean tick (Ixodes ricinus) | 28 |
| [Fig. 15.] | Texas fever tick | 28 |
| [Fig. 16.] | Texas fever tick (Margaropus annulatus) | 29 |
| [Fig. 17.] | Amblyomma variegatum | 29 |
| [Fig. 18.] | Ornithodoros moubata | 36 |
| [Fig. 19.] | The follicle mite (Demodex folliculorum) | 36 |
| [Fig. 20.] | Itch-mite (Sarcoptes scabiei) | 37 |
| [Fig. 21.] | Harvest-mites or "jiggers" | 37 |
| [Fig. 22.] | Horse-fly (Tabanus punctifer) | 44 |
| [Fig. 23.] | Stable-fly (Stomoxys calcitrans) | 44 |
| [Fig. 24.] | A black-fly (Simulium sp.) | 45 |
| [Fig. 25.] | Screw-worm fly (Chrysomyia macellaria) | 45 |
| [Fig. 26.] | Blow-fly (Calliphora vomitoria) | 45 |
| [Fig. 27.] | Blue-bottle fly (Lucilia sericata) | 50 |
| [Fig. 28.] | Flesh-fly (Sarcophaga sp.) | 50 |
| [Fig. 29.] | "The little house-fly" (Homalomyia canicularis) | 51 |
| [Fig. 30.] | Horse bot-fly (Gastrophilus equi.) | 51 |
| [Fig. 31.] | Oxwarble fly (Hypoderma lineata) | 51 |
| [Fig. 32.] | Sheep bot-fly (Gastrophilus nasalis) | 51 |
| [Fig. 33.] | Chigo or jigger-flea, male (Dermatophilus penetrans) | 54 |
| [Fig. 34.] | Chigo, female distended with eggs | 54 |
| [Fig. 35.] | Bedbug (Cimex lectularis) | 55 |
| [Fig. 36.] | Body-louse (Pediculus vestimenti) | 55 |
| [Fig. 37.] | One use for the house-fly | 57 |
| [Fig. 38.] | The house-fly (Musca domestica) | 58 |
| [Fig. 39.] | Head of house-fly showing eyes, antennæ and mouth-parts | 60 |
| [Fig. 40.] | Proboscis of house-fly, side view | 60 |
| [Fig. 41.] | Lobes at end of proboscis of house-fly showing corrugated ridges | 61 |
| [Fig. 42.] | Wing of house-fly | 61 |
| [Fig. 43.] | Wing of stable-fly (Stomoxys calcitrans) | 62 |
| [Fig. 44.] | Wing of house-fly showing particles of dirt adhering to it | 62 |
| [Fig. 45.] | Last three segments of leg of house-fly | 62 |
| [Fig. 46.] | Foot of house-fly | 63 |
| [Fig. 47.] | Larva of house-fly | 63 |
| [Fig. 48.] | Barn-yard filled with manure | 64 |
| [Fig. 49.] | Dirty stalls | 65 |
| [Fig. 50.] | Pupa of house-fly | 76 |
| [Fig. 51.] | Head of stable-fly | 76 |
| [Fig. 52.] | Mass of mosquito eggs (Theobaldia incidens) | 76 |
| [Fig. 53.] | Mosquito eggs and larvæ (T. incidens) | 77 |
| [Fig. 54.] | Mosquito larva (T. incidens), DORSAL VIEW | 77 |
| [Fig. 55.] | Eggs, larvæ and pupæ of mosquitoes (T. incidens) | 78 |
| [Fig. 56.] | Larva of mosquito (T. incidens) | 78 |
| [Fig. 57.] | Mosquito larvæ and pupæ (T. incidens) | 79 |
| [Fig. 58.] | Anopheles larvæ (A. maculipennis) | 79 |
| [Fig. 59.] | Mosquito pupæ (T. incidens) | 80 |
| [Fig. 60.] | Mosquito pupa (T. incidens) | 80 |
| [Fig. 61.] | Mosquito larvæ and pupæ (T. incidens) | 80 |
| [Fig. 62.] | A female mosquito (T. incidens) | 81 |
| [Fig. 63.] | A male mosquito (T. incidens) | 81 |
| [Fig. 64.] | Head and thorax of female mosquito (Ochlerotatus lativittatus) | 82 |
| [Fig. 65.] | Head and thorax of male mosquito (O. lativittatus) | 82 |
| [Fig. 66.] | Head of female mosquito | 83 |
| [Fig. 67.] | Cross-section of proboscis of female and male mosquito | 83 |
| [Fig. 68.] | Wing of mosquito (O. lativittatus) | 86 |
| [Fig. 69.] | End of mosquito wing highly magnified | 86 |
| [Fig. 70.] | Diagram to show the alimentary canal and salivary glands of a mosquito | 87 |
| [Fig. 71.] | Salivary glands of mosquitoes | 87 |
| [Fig. 72.] | Heads of culicinæ mosquitoes | 90 |
| [Fig. 73.] | Heads of anophelinæ mosquitoes | 90 |
| [Fig. 74.] | Wing of Anopheles maculipennis | 90 |
| [Fig. 75.] | Wing of Theobaldia incidens | 90 |
| [Fig. 76.] | A non-malarial mosquito (T. Incidens), MALE, STANDING ON THE WALL | 91 |
| [Fig. 77.] | Female of same | 91 |
| [Fig. 78.] | A malarial mosquito (A. maculipennis), MALE, STANDING ON THE WALL | 91 |
| [Fig. 79.] | Female of same | 91 |
| [Fig. 80.] | Egg of Anopheles, SIDE VIEW | 92 |
| [Fig. 81.] | Egg of anopheles, dorsal view | 92 |
| [Fig. 82.] | Anopheles larvæ | 92 |
| [Fig. 83.] | Anopheles larvæ | 93 |
| [Fig. 84.] | Anopheles larva, dorsal view | 93 |
| [Fig. 85.] | Anopheles pupæ resting at surface of water | 93 |
| [Fig. 86.] | Salt-marsh mosquito (Ochlerotatus lativittatus); MALE | 98 |
| [Fig. 87.] | Salt-marsh mosquito (O. lativittatus); FEMALE | 98 |
| [Fig. 88.] | Top-minnow (Mollienisia latipinna) | 99 |
| [Fig. 89.] | Dragon-flies | 99 |
| [Fig. 90.] | The Young (nymph) of a dragon-fly | 100 |
| [Fig. 91.] | The cast skin (exuvæ) of a dragon-fly nymph | 100 |
| [Fig. 92.] | Diving-beetles and back-swimmers | 101 |
| [Fig. 93.] | Killifish (Fundulus heteroliatus) | 102 |
| [Fig. 94.] | Stickleback (Apeltes quadracus) | 102 |
| [Fig. 95.] | An old watering-trough, an excellent breeding-place for mosquitoes | 103 |
| [Fig. 96.] | Horse and cattle tracks in mud filled with water | 108 |
| [Fig. 97.] | A malarial mosquito (Anopheles maculipennis)MALE | 108 |
| [Fig. 98.] | A malarial mosquito (A. maculipennis) FEMALE | 109 |
| [Fig. 99.] | Diagram to illustrate the life-history of the malarial parasite | 110 |
| [Fig. 100.] | Malarial mosquito (A. maculipennis) ON THE WALL | 111 |
| [Fig. 101.] | Malarial mosquito (A. maculipennis) STANDING ON A TABLE | 111 |
| [Fig. 102.] | Salt-marsh mosquito (O. lativittatus) STANDING ON A TABLE | 118 |
| [Fig. 103.] | Anopheles hanging from the ceiling | 118 |
| [Fig. 104.] | Yellow fever mosquito (Stegomyia calopus) | 122 |
| [Fig. 105.] | Rat-flea (Læmopsylla cheopis); MALE | 152 |
| [Fig. 106.] | Rat-flea (L. cheopis); FEMALE | 152 |
| [Fig. 107.] | Head of rat-flea showing mouth-parts | 153 |
| [Fig. 108.] | Human-flea (Pulex irritans); MALE | 153 |
| [Fig. 109.] | Human-flea (P. irritans); FEMALE | 156 |
| [Fig. 110.] | Mouse-flea (Ctenopsyllus musculi); FEMALE | 156 |
| [Fig. 111.] | Trypanosoma gambiense | 164 |
| [Fig. 112.] | Tsetse-fly | 164 |
INSECTS AND DISEASE
CHAPTER I
PARASITISM AND DISEASE
PARASITES