CONTENTS xi 



PART II 

 CHAPTER I " 



PAGE 



AMCEBA UNICELLULAR AND MULTICELLULAR ANIMALS . . . 22Q 

 PRACTICAL DIRECTIONS 238 



CHAPTER II 



SPH^RELLA AND EUGLENA MONADS AND BACTERIA DIF- 

 FERENCES BETWEEN ANIMALS AND PLANTS SAPROPHYTES 240 

 PRACTICAL DIRECTIONS 259 



CHAPTER III 



PARAMCECIUM : VORTICELLA AND ITS ALLIES COLONIAL ORGAN- 

 ISMS 26l 



PRACTICAL DIRECTIONS 277 



CHAPTER IV 



OPALINA : MONOCYSTIS PARASITES BIOGENESIS AND ABIO- 

 GENESIS CLASSIFICATION OF THE UNICELLULAR ORGAN- 

 ISMS EXAMINED 28o 



PRACTICAL DIRECTONS 293 



CHAPTER V 



HYDRA : OBELIA SYMBIOSIS ALTERNATION OF GENERATIONS 



CHARACTERS OF THE PHYLUM CCELENTERATA ..... 294 

 PRACTICAL DIRECTIONS 322 



CHAPTER VI 



THE EARTHWORM : NEREIS CHARACTERS OF THE PHYLUM 



ANNULATA . . . 326 



PRACTICAL DIRECTIONS 354 



CHAPTER VII 



THE CRAYFISH CHARACTERS OF THE PHYLUM ARTHROPODA . 360 

 PRACTICAL DIRECTIONS 386 



