1104 



SPLANCHNOLOGY 



colon is termed the mesocolon (Fig. 985). About the sixth week a diverticulum 

 of the gut appears just behind the opening of the vitelline duct, and indicates 



Rathke's pouch 



Lung diverticulum /- 



Stomach - 

 Liver - 



Opening into _ 

 yolk-sac 



Allantois I *| -- 



, Mandibular 

 arch 



Postallantoic part 

 of hind-gut 



Wolffian duct 



Lung diverticulum 

 Esophagus ^ *S 



Stomach 

 Pancreas 



Bile-duct 



Vitdline duel" 

 Allantois - 



Thyroid gland 



Mandibular arch 

 i Notochord 



Rathke's pouch 



Postallantoic part 

 of hind-gut 



-/ Wolffian duct 



Fra. 982. Sketches in profile of two stages in the development of the human digestive tube. (His.) 



A X 30. B X 20. 



the future cecum and vermiform process. The part of the loop on the distal side 

 of the cecal diverticulum increases in diameter and forms the future ascending 



