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 OAMETOGENESIS '(SPERMATO- 



GENESIS AND OOGENESIS) .MATURATION AND FERTILISA- 

 TION OF THE OVUM DIFFERENT TYPES OF OVA AND OF 



SEGMENTATION -EFFECT OF FOOD-YOLK ON DEVELOP- 

 MENT 558 



PRACTICAL DIRECTIONS 575 



CHAPTER XIII 



DEVELOPMENT OK THE LANCELET : EARLY DEVELOPMENT OF 

 OTHER TYPES, INCLUDING THE CHICK AND RABBIT 

 FORMATION OF THE CHIEF ORGANS OF VERTEBRATES, 

 AND OF THE AMNION, ALLANTOIS, AND PLACENTA . . . 577 

 PRACTICAL DIRECTIONS 615 



INDEX 619 



