LIST OF ILLUSTRATIONS. 



FIG. FAGB 



KENTISH PLOVER WITH EGGS AND YOUNG Frontispiece 



1 . SPIRACLES AND AIR-TUBES OF COCKROACH . . . . . . 3 



2. GILLS OF MUSSEL . . . . . . . . . . 4 



3. A CELL GREATLY MAGNIFIED .. .. .. ..11 



4. AMCEBA . . . . . . . . . . 12 



5. EGG-CELL AND SPERM-CELL . . 13 



6. DIAGRAM OF CIRCULATION .... 23 



7. PROTOZOA ...... 38 



8. HYDRA VIRIDES .... 43 



9. AURELIA : LIFE-CYCLE . . . . 45 



10. LIVER-FLUKE EMBRYONIC STAGES . . . . 47 



11. DIAGRAM OF DEVELOPMENT .. .. .. ..51 



12. WING OF BAT (PIPISTRELLE) . . . . . . . . 64 



1 3. VARIATIONS OF THE NOCTULE . . . . . . 67 



14. LONG-EARED BAT . . . . . . 68 



15. PIPISTRELLE .. .. .. ..69 



16. WHISKERED BAT . . . . . . 70 



17. VARIATIONS ADJUSTED TO THE STANDARD OF THE NOCTULE . . 73 



18. CATERPILLAR OF A MOTH ON AN OAK SPRAY . . . . 85 



19. LOCUST RESEMBLING A LEAF . . . . . . 86 



20. MIMICRY OF BEES BY FLIES . . . . . . . . 91 



21. EGG AND HEN .. .. .. .. .. ..141 



22. STAG-BEETLES .. .. .. .. .. .. 180 



23. TACTILE CORPUSCULES . . . . . . . . . . 247 



24. TOUCH-HAIR OF INSECT . . . . . . . . . . 248 



25. TASTE-BUDS OF RABBIT . . . . . . . . . . 250 



26. ANTENNULE OF CRAYFISH . . . . . . . . 259 



27. DIAGRAM OF EAR . . . . . . . . . . . . 263 



28. TAIL OF MYSIS .. .. .. .. .. 266 



29. LEG OF GRASSHOPPER .. .. .. .. .. 266 



SO.'DIAGRAM OF SEMICIRCULAR CANALS 270 



