CONTENTS ix 



CHAPTER PAGE 



LVI. SEX 296 



LVII. FLOWERS 300 



LVI 1 1. POLLEN ATION 304 



LIX. ADAPTATIONS OF FLOWERS 310 



LX. FRUIT AND SEED DISTRIBUTION 315 



LXI. ALTERNATION OF GENERATIONS ........ 320 



LXII. REPRODUCTION 'IN ANIMALS 327 



LXIII. INFANCY AND PARENTAL CARE . 331 



PART IV. ORGANISMS IN THEIR EXTERNAL RELATIONS 



LXIV. OBSTACLES TO LIFE 337 



LXV. THE CONFLICT OF LIFE WITH LIFE 341 



LXVI. PROTECTIVE ARMORS OF ORGANISMS 345 



LXVIL PROTECTIVE PIGMENTS AND APPEARANCES . . . . 351 



LXVIII. PROTECTIVE MOVEMENTS 360 



LXIX. PROTECTIVE ACTIVITIES . 368 



LXX. THE FOREST IN RELATION TO MAN 377 



LXXI. BACTERIA AND HEALTH 386 



LXXII. CONTROL AND USE OF BACTERIA 394 



LXXI 1 1. INSECTS AS SPREADERS OF DISEASE 398 



LXXIV. INSECTS AS INTERMEDIATE HOSTS 404 



LXXV. INSECTS AND HUMAN WEALTH 412 



LXXVI. INSECTS AND OTHER ORGANISMS . . . . . . .417 



LXXVII. BIRDS IN RELATION TO MAN 425 



LXXVI II. SOCIAL LIFE OF ORGANISMS 430 



PART V. HEREDITY AND EVOLUTION 



LXXIX. VARIATION . 437 



LXXX. HEREDITY 443 



LXXXI. APPLICATIONS OF THE PRINCIPLES OF HEREDITY . 450 



LXXXII. HEREDITY AND PROTOPLASM 457 



LXXXIII. EVOLUTION 463 



LXXXIV. APPLICATIONS AND THEORIES OF EVOLUTION . . . 471 



