438 DISSECTION OF THE PIGEON. 



and runs back to open into the distal limb of the 

 duodenum, about the junction of its middle and 

 distal thirds. 



E. The Pancreas. 



The pancreas is a compact pinkish gland lying in the loop 

 of the duodenum, along nearly the whole of its length, and 

 grooved by it. 



The pancreatic ducts are three in number, and all open 

 into the distal limb of the duodenum. 



The first two ducts leave 4he right border of the gland 

 about the middle of its length, and run forwards, parallel to 

 each other, to open close together into the distal limb of the 

 duodenum, about the middle of its length, and close to the 

 right bile-duct. 



The third pancreatic duct is longer than the others. It 

 leaves the gland near its anterior end, and runs forwards to 

 open into the distal limb of the duodenum, close to its junction 

 with the small intestine. 



Pin out the duodenum on a dissecting board, and expose 

 the bile-ducts and pancreatic ducts. The dissection is best 

 performed under ivater, and from the dorsal surface. 



Y. DISSECTION OF THE CIRCULATORY SYSTEM. 



A. The Heart. 



The heart of the bird is large, and is divided into four 

 chambers, those of the right side being completely separated 

 from those of the left. The right side of the heart receives 

 the blood which is brought back by the veins from all parts 

 of the body, and drives it to the lungs to be aerated : from 

 the lungs it is returned to the left side of the heart, and thence 

 driven all over the body through the arteries. The right side 

 of the heart therefore contains venous blood, and the left side 

 arterial blood. 



Open the pericardial cavity so as to expose the heart fully ; 

 and dissect away the connective tissue and fat from the vessels 

 at the base of the heart. 



