CONTENTS. 9 



CHAPTER XV. 



SEGMENTATION OF THE VITELLUS AND FOEMATION OF THE MEMBRANES 

 AND PLACENTA. 



Deformation and gyration of the vitellus Polar globule Vitelline nucleus 

 Segmentation of the vitellus Primitive trace of the embryon Blastoder- 

 mic layers Formation of the membranes Formation of the amnion 

 Amniotic fluid Formation of the umbilical vesicle Formation of the al- 

 lantois and the permanent chorion Umbilical cord Membranae deciduae 

 Development and structure of the placenta Structure of the fully-devel- 

 oped placenta Blood-vessels of the placenta, . . . Page 354 



CHAPTER XYI. 



DEVELOPMENT OF THE EMBEYON THE OSSEOUS, MTJSCTJLAK, CUTANEOL'S, 

 AND NEKVOUS SYSTEMS. 



General view of the development of the embryon Development of the cavities 

 and layers of the trunk in the chick External blastodermic membrane 

 Intermediate membrane, in two layers Internal blastodermic membrane 

 Neural canal Chorda dorsalis Primitive aortae Vertebrae Origin of the 

 Wolffian bodies Pleuro-peritoneal cavity Development of the skeleton 

 Ossification of the skeleton Development of the muscles Development of 

 the skin Development of the nervous system Development of the enceph- 

 alon Development of the organs of special sense Cartilage of Meckel, 387 



CHAPTER XVII. 



DEVELOPMENT OF THE ALIMENTAEY SYSTEM, THE EESPIEATOEY SYSTEM, 

 AND THE FACE. 



First appearance of the intestinal canal Formation of the mesentery Forma- 

 tion of the stomach Development of the large intestine Appearance of 

 the intestinal villi Formation of the pharynx and esophagus Develop- 

 ment of the anus The liver, pancreas, and spleen Development of the 

 respiratory system Development of the face Visceral arches, and their 

 development Malformations of the face Development of the teeth, 405 



CHAPTER XVIII. 



DEVELOPMENT OF THE GENITO-UEINAEY AND OF THE CIECULATOEY 



SYSTEM. 



Development of the Wolffian bodies Ducts of the Wolffian bodies and ducts of 

 Miiller Development of the Wolffian ducts into the vasa deferentia, and 



