ORGANS OF DIGESTION. 123 



On the other side of the notch is a small left median lobe 

 and a much larger left lateral lobe. The right lateral lobt 

 is dorsal of the right median lobe, and is divided into two 

 parts by a deep cleft. A fifth lobe known as the Spigelian 

 or caudate lobe is a small triangular portion oi the liver 

 connected to the base of the right lateral lobe and lying be- 

 tween the neck of the gall bladder and the end of the stom- 

 ach joining the esophagus. 



The bile secreted by the liver passes through the several 

 ducts from the various lobes, to the main hepatic duct, 

 which may be seen by cutting away the liver from the right 

 side of the gall-cyst, and carefully picking off the perito- 

 neum ensheathing the vessels between the Spigelian lobe 

 and the cystic duct. The latter is somewhat convoluted in 

 its course from the deeply imbedded end of the cyst, to a 

 point on the duodenum about three centimeters from the 

 pylorus. The main hepatic duct joins the cystic duct (Fig. 

 60) near its middle. The common duct thus formed is 

 known as the common bile duct. When the bile is secreted 

 faster than it is permitted to enter the intestine, it passes 

 backward from the common bile duct into the cyst. 



The bile aids in the absorption of the fats by the villi, 

 and renders the chyme alkaline. The formation of red 

 blood-corpuscles takes place in the liver of the embryo, 

 while in the adult, the liver destroys these corpuscles. The 

 chief function of this organ, however, is the formation of 

 glycogen from the sugars and starches eaten and the gradual 

 transformation of this glycogen into sugar as demanded for 

 the nutrition of the body. Diabetes mellitus is caused by a 

 diseased liver or pancreas which permits sugar to accumu- 

 late in the blood. 



The pancreas (Fig. 60) is an elongated gland bent at 

 a right angle near its middle. The body of it lies dorsal 

 to the pyloric portion of the stomach, and the head lies 



