xii CONTENTS 



CHAPTER VIII 



PAGE 



THE FRESH-WATER MUSSEL CHARACTERS OF THE PHYLUM 

 MOLLUSCA ENUMERATION OF THE CHIEF PHYLA OF THE 



ANIMAL KINGDOM 396 



PRACTICAL DIRECTIONS 412 



CHAPTER IX 



CHARACTERS OF THE PHYLUM VERTEBRATA THE LANCELET . 418 

 PRACTICAL DIRECTIONS 426 



CHAPTER X 



CHARACTERS OF THE CLASS PISCES THE DOGFISH 430 



PRACTICAL DIRECTIONS 472 



CHAPTER XI 



CHARACTERS OF THE CLASS MAMMALIA THE RABBIT .... 482 

 PRACTICAL DIRECTIONS . 542 



CHAPTER XII 



THE MINUTE STRUCTURE OF CELLS CELL DIVISION STRUC- 

 TURE OF THE OVUM SPERMATOGENESIS AND OOGENESIS 

 MATURATION AND FERTILIZATION OF THE OVUM 

 SEGMENTATION OF THE OOSPERM EFFECT OF FOOD-YOLK 

 ON DEVELOPMENT FORMATION OF THE CHIEF ORGANS 

 OF VERTEBRATES, AND OF THE AMNION, ALLANTOIS, 



AND PLACENTA 558 



PRACTICAL DIRECTIONS 603 



INDEX 607 



