PERICARDIUM, PLEUROPERITONEUM, DIAPHRAGM AND MESENTERIES. 379 



with the transverse mesocolon and transverse colon (Fig. 341). During the 

 first or second year after birth the two lamellae fuse with each other caudal 

 to the transverse colon to form the greater omentum of adult anatomy. 



Diaphragm . 



Lesser omentum 



Pancreas 

 Bursa omentalis 



Stomach 



Greater omentum 



Duodenum 



Transverse mesocolon 



Transverse colon 



Mesentery of 

 small intestine 



Small intestine ----- V\~ 



FIG. 339. 



Diaph. 



FIG. 340. FIG. 341. 



FIGS. 339, 340 and 341. Diagrams showing stages in the development of the bursa omentalis, the 

 greater omentum, and the fusion of the latter with the transverse mesocolon. Diagrams 

 represent sagittal sections. For explanation of lettering in Figs. 340 and 341 see Fig. 339. 



The Lesser Omentum. It has already been noted that the liver grows into 

 the caudal portion of the septum transversum (p. 374). Since the ventral 

 mesentery in the abdominal region, or the ventral mesogastrium, is primarily 



