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 Repre- 

 sentative 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 Changes in Move- 



