DISSECTION OF THE ABDOMEN. 313 



kidney. The spleen is retained in the left hypochondrium by the gastro- 

 splenic omentum, and by a special sjilenic ligament. The gastro-splenic 

 omentum forms a loose connection between the left half of the greater 

 curvature of the stomach and the anterior border of the spleen. The 

 splenic ligament is a fold of peritoneum developed at the base of the 

 organ, and formed by the serous membrane in passing from around the 

 anterior end of the left kidney to envelop the spleen. 



The Pancreas (Plate 44) is a body having a lobulated structure and a 

 very irregular shape. It is placed across the roof of the abdominal cavity, 

 its central portion underlying the last dorsal vertebrae. Its upper face 

 is applied to the aorta, the coeliac axis, the vena cava, the pillars of the 

 diaphragm, and the right kidney, and is partly covered by peritoneum. 

 Its lower face towards the right is adherent to the crook of the caecum 

 and the termination of the double colon, while to the left it is covered 

 by peritoneum. Its anterior border is related to the stomach, the 

 duodenum, and the liver. Its posterior border is related about its centre 

 to the anterior mesenteric artery. Its right extremity, or head, is in 

 contact with the duodenum; while the left extremity, or tail, is related 

 to the base of the spleen. The entire thickness of the gland is perforated 

 by the portal vein, which passes from its lower to its upper surface 

 through what is named the pancreatic ring. The gland possesses two 

 excretory ducts, both of which leave it at its right extremity. The main 

 duct is named the duct of Wirsimg, and it perforates the wall of the 

 duodenum about six inches from the pylorus, and close by the point of 

 entrance of the bile duct. The accessory duct is much smaller, and pene- 

 trates the bowel at a point opposite the entrance of the duct of Wirsung. 

 The healthy fresh pancreas has a greyish-yellow colour ; but when 

 decomposition sets in after death, this speedily changes to an almost 

 black hue. 



The Liver (Plates 43 and 44) is the largest gland in the body. It 

 forms the bile and discharges it into the duodenum. In health it has a 

 reddish-brown colour and a moderately firm consistence. In form it is 

 not comparable to any common object, and its irregularity of shape makes 

 its description somewhat difficult. It should be observed, in the first 

 place, that inferiorly the rim of the organ is deeply indented, or 

 notched, and two of the largest of these notches serve to partially 

 divide the gland into its three main lobes, viz., a right, a left, and 

 a middle, or lobulus quadratus. Of these the middle lobe is always 

 the smallest, and its inferior border shows two or three minor indenta- 

 tions. The left lobe is generally the largest, but sometimes it is less 

 than the right. The liver possesses a fourth lobe, in the form of 

 a small projection of liver substance about the size of two or three 

 of the human fingers, and situated at the vipper part of the right lobe. 

 This is the homologue of the lobulus caudatus of the human subject. 



