THE PANCREAS. THE LIVER. 187 



The spleen varies in weight from two drachms to forty 

 pounds ; its average is from five to seven ounces. Its size 

 may be averaged at five inches in length by three or four 

 in width, and one to two inches in thickness. Within the 

 folds of the peritoneum, in the neighborhood of this viscus, 

 it is not uncommon to find supplementary spleen*, small 

 rounded bodies, varying from the size of a pea to that of a 

 pigeon's egg; in structure these are similar to that of the 

 pleen proper. 



THE PANCREAS. 



The PANCREAS is an irregularly shaped viscus, some six 

 inches in length, lying transversely upon the vertebrae, 

 behind the stomach. It is a conglomerate gland, the sub- 

 stance of which is of a pale color, and broken up into easily 

 separated lobules. It is divided into a head and body, the 

 head being that portion embraced by the duodenum. A 

 portion of the gland surrounds the mesenteric vessels, and 

 this prolongation is sometimes "called the lesser pancreas. 

 By making a longitudinal incision into the substance of the 

 pancreas, and carefully separating the lobules, a delicate 

 white duct will be exposed; this is the pancreatic duct ; 

 it commences at the extremity of the gland, and gradually 

 increasing in size by the accession of small branches, makes 

 its exit at the head of the viscus, and, in company with the 

 ductus choledochus communis, penetrates obliquely through 

 the walls of the duodenum at the posterior part of its per- 

 pendicular portion, opening into its interior by a common 

 orifice with the bile duct. Occasionally it has a separate 

 aperture, and there may be a second, supplementary duct. 



THE LIVER. 



By lifting the cartilages of the right side with the chain hooks, and 

 by lifting and drawing the liver in different directions, its attach- 

 ments and relations may be successively observed and studied. 



The LIVER is a conglomerate gland,- and the largest vis- 

 cus in the body ; it weighs from" three to four and a-half 

 pounds ; tys color is a reddish-brown, and its surface is 

 covered with peritoneum, except in such intervals as arc 

 left between the layers reflected from the viscus to the 

 parietes of the abdomen, and which constitute the liga- 

 ments which hold it in place. It is in relation superiorly 

 and anteriorly with the diaphragm and abdominal parietes ; 

 inferiorly with the stomach and transverse colon, and pos- 



