DISSECTION OF THE ABDOMEN. 323 



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 

 penetrates 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 indentations. The left lobe 

 is generally the largest in old subjects, but in early life it is smaller 

 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 upper part of the right lobe.. 

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



The exact form of the liver will be more distinctly seen when it has 

 been removed from the body ; but while it remains in situ the student 

 may endeavour to make out the following points : Viewing the organ 

 as a whole, it may be described as having an anterior and a posterior 

 surface, and a circumference divisible into an upper and a lower border. 

 The anterior surface is closely applied to the diaphragm, and is convex. 

 The posterior vena cava, in descending from the spine to the foramen 

 dextrum, passes between this surface and the diaphragm ; and its 

 course is marked on the liver by a vertical groove, which may be 

 termed the anterior fissure. The posterior surface, when the organ 

 is in situ, is concave ; but when the liver is removed from the body 

 this surface, like the anterior, is slightly convex. It presents the portal 

 fissure (L. porta, a gate), by which the portal vein, hepatic artery, bile 

 duct, and hepatic nerves and lymphatics enter the liver. The upper 

 border shows about its centre a rounded notch for the reception of 

 the short abdominal portion of the oesophagus. The lower border shows 

 the sharper and deeper indentations dividing the liver into its three 

 principal lobes, and the lesser indentations that partially subdivide the 

 lobulus quadratus. 



The liver is situated in the epigastric and right and left hypo- 

 chondriac regions. Its most important relations, besides those already 

 mentioned, are as follows : The anterior surface is applied to the 

 diaphragm, the right lobe, which has the highest point of contact, 



