CONTENTS. XIX 



CHAPTER IX. 



AMNION AND ALLANTOIS DEVELOPMENT OF THE CHICK. 



PAGE 



Necessity for accessory organs in the development of birds and quadrupeds 

 Formation of amniotic folds Their union and adhesion Growth of allantois 

 from lower part of intestine Its vascularity Allantois in the egg of the 

 fowl Respiration of the egg Absorption of calcareous matter from the 

 shell Ossification of skeleton Fracture of egg-shell Casting off of amuion 

 and allantois . . . . . . 599-607 



CHAPTER X. 



DEVELOPMENT OF THE EGG IN THE HUMAN SPECIES FORMATION OF THE 



CHORION. 



Conversion of allantois into chorion Subsequent changes of the chorion 

 Its villosities Formation of bloodvessels in villosities Action of villi of 

 chorion in providing for nutrition of fretus Proofs that the chorion is formed 

 from the allantois Partial disappearance of villosities of chorion, and 

 changes in its external surface ...... 608-613 



CHAPTER XI. 



DEVELOPMENT OF UTERINE MUCOUS MEMBRANE FORMATION OF THE 



DECIDUA. 



Structure of uterine mucous membrane Uterine tubules Thickening of ute- 

 rine mucous membrane after impregnation Decidua vera Entrance of egg 

 into uterus Decidua reflexa Inclosure of egg by decidua reflexa Union 

 of chorion with decidua Changes in the relative development of different 

 portions of chorion and decidua ..... 614-620 



CHAPTER XII. 



THE PLACENTA. 



Nourishment of foetus by maternal and fcetal vessels Arrangement of the 

 vascular membranes in different species of animals Membranes of fcetal 

 pig Cotyledon of cow's uterus Development of foetal tufts in human pla- 

 centa Development of uterine sinuses Relation of foetal and maternal 

 bloodvessels in the placenta Proofs that the maternal sinuses extend 

 through the whole thickness of the placenta Absorption and exhalation 

 by the placental vessels ...... 621-629 



