xiv TABLE OF CONTENTS. 
CHAPTER VIII. 
Some Insect Adaptations. 
CHAPTER IX. 
A Spider’s Activities, 
CHAPTER X. 
Homologies among Crustacea. 
CHAPTER XI. 
The Activities of One-Celled Animals and Sponges. 
CHAPTER XII. 
The Hydra and Some Ccelenterates which Live in Colonies 
CHAPTER XIII. 
The Starfish and Closely Related Animals. 
CHAPTER XIV. 
The Earthworm and His Work. 
CHAPTER XV. 
Mussels and Snails, 
CHAPTER XVI. 
The Structure and Activities of a Fish. 
CHAPTER XVII. 
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IOI 
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155 
169 
Tadpoles and Frogs 
179 
