pe CONTENTS 
CHAPTER. L1TI 
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— 
