x CONTENTS 



CHAPTER III 

 THE GREAT DEEPS 



PAGE 



The Challenger Expedition The Deep Deep Sea 

 Great Pressure Very Cold Very Dark 

 Very Calm and Silent Monotony No Depth 

 Limit to Life No Plants in the Deep Sea 

 No Rottenness A Representative Fauna 

 Fitnesses of Deep-Sea Animals Puzzle of 

 Phosphorescence Big Eyes and Little Eyes 

 Origin of Deep-Sea Animals Hunger and 

 Love in the Deep Sea Retrospect . . .104 



CHAPTER IV 

 THE FRESH WATERS 



Variety of the Fresh Waters Similar Animals in 

 Widely Separated Places From Salt Water 

 to Fresh Origin of Fresh- Water Animals 

 Circulation of Matter in the Fresh Waters 

 The Web of Life in the Fresh Waters The 

 Danger of Drought The Danger of Frost 

 The Danger of Flood Parental Care among 

 Fresh-Water Animals The Story of the Eel 

 The Story of the Salmon The Story of 

 the Lamprey Water Insects The Story of 

 the Fresh- Water Spider 136 



CHAPTER V 

 THE CONQUEST OF THE DRY LAND 



Tell-tale Evidences of Marine Ancestry Origin of 

 Land Plants The Three Great Invasions of 

 the Dry Land New Ways of Breathing 





