List of Illustrations. 



FIO. PACK 



25. TASTE-BODS OF RABBIT . . . . . . . . . . 250 



i LE OF CRAYFISH .. .. .. .. i!.v.i 



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



28. TAIL OF MTSIS . . . . . . . . . . 266 



29. LEO OF GRASSHOPPER .. .. .. .. ..266 



30. DIAGRAM OF SEMICIRCULAR CANALS .. .. .. -JTn 



31. THE HUMAN EYE . . . . . . . . . . . . 274 



32. RETINA OF THE EYE . . . . . . . . . . -274 



33. VARIATION IN THE LIMITS OF COLOUR-VISION . . . . . . 281 



34. PINEAL EYE . . . . . . . . . . . . 288 



35. SKILL OF MELANERPETON . . . . . . . . . . 288 



36. EYES AND EYELETS OF BEE . . . . . . . . 289 



37. EYE OF FLY . . . . . . . . . . . . 290 



38. DIAGRAM OF MOSAIC VISION .. .. .. .. 291 



39. DIRECTION-RETINA . . . . . . . . . . . . 295 



40. ANTENNAUY STRUCTURES OF HYMENOI-TKKA 297 



