viii CONTENTS 



CHAPTER PAGE 



36. ARTHROPODA (CLASSIFICATION) . . . . . . .257 



37. HENRI FABRE 280 



38. LEPIDOPTERA ..... , * . . . 286 



39. BEES . .293 



40. ANTS ... . . . * 299 



41. SCALE INSECTS 308 



42. GRASSHOPPERS AND THEIR RELATIVES 313 



43. PROCHORDATA AND CYCLOSTOMES 320 



44. THE STRUCTURE OF THE VERTEBRATES 328 



45. FISHES 342 



46. AMPHIBIANS 358 



47. REPTILES 364 



48. BIRDS 373 



49. MAMMALS 396 



50. THE EVOLUTION OF THE HORSE AND ELEPHANT . . -417 



51. THE EVOLUTION OF MAN 429 



52. THE CHARACTERS OF HOMO 435 



53. THE GEOGRAPHICAL DISTRIBUTION OF LIFE .... 442 



54. THE BIOLOGICAL REGIONS OF THE WORLD .... 447 



55. LIFE ZONES 454 



56. LIFE IN THE TROPICS . . 463 



57. LIFE IN THE ARCTIC AND ANTARCTIC REGIONS .... 467 



58. LIFE IN THE SEA . . 472 



59. Louis PASTEUR 479 



60. DISEASE IN RELATION TO HUMAN EVOLUTION .... 489 



61. HISTORY FROM A BIOLOGICAL POINT OF VIEW .... 492 



62. EUGENICS 500 



63. Louis AGASSIZ 508 



64. SPENCER FULLERTON BAIRD AND THE UNITED STATES NATIONAL 



MUSEUM . . . . . . . ...;.. 520 



65. SOCIOLOGY FROM A BIOLOGIST'S POINT OF VIEW . . . 530 



66. SOME GENERAL RESULTS . . . . .. . -535 



THE LAST LECTURE . . . . . .., ri.^; ;...; 538 

 INDEX -.- . . . . 541 



