CONTENTS OF VOLUME I. 



INTRODUCTION. Pp. i 16. 

 CHAPTER I. THE OVUM AND SPERMATOZOON. 



(leneral history of the Ovum, pp. 17 15. Special history of the Ovum in 

 different types, pp. 3665. The Spermatozoon, pp. 6567. 



CHAPTER II. THE MATURATION AND IMPREGNATION OF THE OVUM. 



Maturation of the Ovum, and formation of the polar bodies, pp. 68 79, 

 Impregnation of the Ovum, pp. 79 86. Summary, pp. 86. 



CHAPTER III. THE SEGMENTATION OF THE OVUM. 



Internal phenomena of Segmentation, pp. 88 91. External features of 

 Segmentation, pp. 91 in. 



INTRODUCTION TO SYSTEMATIC EMBRYOLOGY. Pp. 125 130. 



CHAPTI.K IV. DICYEMID/E AND OKTHONECTID/E. Pp. 131137. 

 CHAPTER V. PORIFERA. Pp. 138 151. 

 CHAPTER VI. CCELENTERATA. 



Hy.lro/oa, pp. 153 167. Actinozoa, pp. 167 173. Ctcnophora, pp. 173 

 178. Summary, etc., pp. 178181. Alternations of generations, pp. 181 

 187. 



CHAPTER VII. PLATYELMINTHES. 



Turbellaria, pp. 189 196. Ncmcrtea, pp. 196104. Trematoda. pp. 105 

 no. Cestoda, pp. 110118. 



CHAPTER V11I. ROTIFERA. Pp. aai 224. 



