TABLE OF CONTENTS. 



Introduction 



External form 



Integument 



Nervous system . . . 



Brain 



Medullary tube . 



Xeuromeres. . . . 



Cerebral nerves 



Ganglionic crest. 

 Digestive system . . 



Mouth . . 



PAGE, 

 127 



128 

 130 

 131 

 131 

 131 

 131 

 133 

 134 

 135 

 13.5 



Foregut 135 



Pharynx 135 



Pulmonary diverticulum 137 



Gastric 1 region 138 



Hepatic diverticulum 138 



Yolk stalk and sac 140 



Hindgut and cloaca 140 



Allantoic duct. . . . 141 



Cloacal membrane 141 



Caudal intestine .... 141 



Histological structure of the digestive tube 141 



Somites 142 



Chorda dorsalis ... 144 



Nephric system. . . 147 



Vascular system . . 149 



Heart 149 



Veins 152 



Vena cardinalis anterior. . . . 152 



Vena cardinalis posterior. ... 154 



Vena cardinalis communis 155 



Vense umbilicales 155 



Vascular system continued. 

 Veins continued. 



Vena' vitellina* 



Sinus venosus 



Arteries 



Aorta vent rails 

 Aortic arches .... 



Aorta- dorsales 



Branches of the dorsal aorta*. 

 Anterior branches 



156 

 157 

 157 

 157 

 157 

 158 

 158 



158 



Dorsal segments! arteries 159 



Ventral segment al arteries 160 



Lateral scgmental arteries. . . 160 



Terminal branches 160 



Arteria- umbilicales Kil 



Co-loin . . . 161 



Pericardia! cavity . . 161 



Pleuro-peritoneal cavity .... 161 



Mesot helium. 162 



Septum transversum , 163 



Embryonic membranes 163 



Amnion 163 



Line of reflection . . . 163 



Histological structure. 164 



Chorion 165 



Cliorionic membrane 165 



Chorionic villi 16.1 



Histological structure 165 



Explanation of figures 166 



Abbreviations 167 



Bibliography . .... 168 



126 



