ILLUSTRATIONS 



A portrait of the head of an Esquimo attacked by 



mosquitos ..... Frontispiece 



1. Periplaneta orientalis, male, dorsal view ... 2 



2. P. orientalis, male, side view ..... 6 



3. Mouth parts of P. orientalis ..... 9 



4. P. orientalis, female, dissected ..... 10 



5. Egg capsule of P. orientalis ..... 12 



6. Cast skin of the nymph stage of cockroach . . 18 



7. Nymph stage of cockroach escaping from old skin . 19 



8. Hypoderma bovis ....... 29 



9. Eggs of H. lineatum ....... 33 



10. Eggs of H. bovis 35 



11. Entrance hole of H. lineatum ..... 37 



12. Cow being chased by warble-fly ..... 40 



13. Side-view of head of Anopheles maculipennis, female . 44 



14. Section through proboscis of A. maculipennis, female . 45 



15. Piercing-lancets of A, maculipennis, female. . . 46 



16. A. maculipennis, female, sucking blood ... 58 



17. A. maculipennis, male ...... 66 



18. Stridulating organ of A. maculipennis ... 70 



19. Larva and eggs of A. maculipennis .... 78 



20. Side view of the head of larva of A. maculipennis . 81 



21. Under surface of head of larva of ^. «iacMZipenn»5 . . 82 



