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. _Amoeba_ 20 FIG. 9. _Euglina virdis_ 21 FIG. 10. _Spirocheta duttoni_ 21 FIG. 11. _Paramoecium_ 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