ILLUSTRATIONS 



Page 



Page-Heading 9 



The Dog Is a Civilized Wolf 13 



The Horse and One of Its Ancestors 19 



A Bayonet of the Wild Ox 22 



Children of the Sky 23 



The Camel's Backbone Is Straight 27 



The Jungle Fowl 30 



The Rock-Dove 33 



Appendix in Man, Ape and Rat 43 



Ruins of Hind Limbs in the Whale 44 



Unused Toes of the Cow 45 



The Call of the Wild 54 



Exercising Unused Muscles 56 



The Goose Covers Her Eggs 59 



The Stickleback Father Guarding His Nest 63 



Ducks "Bathing" in a Dry Lot 78 



I ""nds and Seas at the Beginning of the Eocene Period. . 86 



The Spread of Mankind 89 



Women, Among Savages, Do the Hard Work 100 



The Mother Instinct 125 



Every Antelope in South Africa Has to Run for Its Life 



Every Day or Two 132 



The Fear of Snakes Comes From the Far Past 134 



Some of the Things in Our Nature That We Would Be 



Better Off Without 143 



Nature's Schooling 153 



The Bee Does Not Dread Work 162 



The Spirit of Humanity 182 



Following the Leader 185 



