iv Contents 



PAGE 



Visitors from the sea Birds of the moorland The cuckoo 

 Migration The purpose served by migration Causes of 

 migration How do migrants find their way ? "Homing" 

 Plumage coloration Courtship and mating Voice Song 

 Nesting habits Ground-nesting Cliff-nesting The use of 

 old nests Chicks and nestlings Transporting the young 

 The study of birds' eggs Behaviour of birds. 



XIII. NATURAL HISTORY. II. MAMMALS . . . 451 



Origin Earliest mammals Archaic mammals Modern types 

 The egg-laying mammals The pouch-bearing mammals 

 Playing 'possum The placental mammals Many habitats 

 Aquatic mammals Subterranean mammals Arboreal mam- 

 mals Aerial mammals Mammals of deserts and steppes 

 Mountain mammals The story of the snow-mouse Food-get- 

 ting among mammals Chewing the cud Weapons The 

 story of antlers Protective adaptations Nocturnal mam- 

 mals The story of the badger The hedgehog Hibernation 

 Sex dimorphism Family life Care of the young The 

 story of the otter The common hare The significance of 

 play The story of the weasel Social mammals The story 

 of the beaver Mutual aid Variety among mammals Gen- 

 eral characters Orders. 



XIV. NATURAL HISTORY. III. THE INSECT WORLD . 503 



Insects almost ubiquitous The success of insects Protective 

 adaptations Pedigree General characters Locomotion In- 

 stincts and intelligence Homing Intelligent behaviour 

 Ants Marvels of the ant-hill The wonderful leaf -cutting ant 

 Ways of army ants Bees The beehive The queen The 

 bees' diligence Nurseries The swarm Honeycomb Nup- 

 tial flight Massacre of the males Humble-bee The story 

 of wasps' nests How the wasp works and dies Cabbage 

 white butterfly Beetles An important linkage Life his- 

 tories Insects and man Locusts. 



XV. THE SCIENCE OF THE MIND: THE NEW PSY- 

 CHOLOGY; PSYCHO-ANALYSIS .... 539 



The senses The brain Mind in evolution Mind and matter 

 Mental processes The importance of complexes The 

 herd-complex Two main types Conflicts Psycho-analysis 

 Professor Freud's theories The subconscious Cases of 

 mental disorders Dreams. 



