THE ABDOMEN, INTERIOR. 485 



duodenum by its duct, which opens into this part of the 

 bowel. 



The pancreas arises from budding cells posterior to the 

 duodenum and between the two layers of the mesoduode- 

 num ; its duct opens into that of the bile duct. 



The spleen arises posterior to the stomach, and also be- 

 tween the two layers of the mesogaster. 



(10) After the rotation of the intestines and the change 

 to the oblique position by the stomach, the great omentum 

 is formed by the pouching of the mesogaster, below the 

 spleen and as far as the first part of the duodenum, to the 

 left and forward, to form a bag that hangs down in front of 

 the rest of the intestines. Diags. 36, 37. 



(i i) In the formation of the great omentum, the attach- 

 ments of the primary mesogaster and transverse meso- 

 colon are altered, until the great omentum seems, in the 

 adult, to come from the lower border of the stomach to 

 the anterior border of the colon, having looped down to 

 form the apron. Consequently there is only one process 

 of peritoneum which forms the posterior attachment of the 

 great omentum, and it is between the folds of this the great 

 omentum that the colon is situated, and the part of the 

 great omentum passing to the backbone is called the trans- 

 verse mesocolon. Diags. 38 and 40. 



(12) If the fcetal form remains throughout life the pos- 

 terior fold of the omentum returns to the backbone for a 

 separate attachment above the attachment of the meso- 

 colon. Diag. 37. 



The description of the abdominal viscera will be brief 

 and only include the gross anatomy. The descriptions will 

 also be given consecutively, and their dissection later. This 

 is to avoid unnecessary repetition. 



