102 



ANIMAL PHYSIOLOGY. 



its action is -weak compared with that of the gastric and 

 pancreatic juices. 



Fig. 57. DUODENUM, PANCREAS, LIVER, AND SPLEEN. " 'a, Duo- 

 denum ; 6, pancreas, with the pancreatic duct laid bare ; c, d, 

 right and left lobes of the liver, seen from below ; e, obliterated 

 umbilical vein ; /, gall bladder, opening into the cystic duct 

 which joins with the hepatic duct, to form the ductus communis 

 choledochus; g, spleen. 



71. In considering the use of the bile in the intestine, it is 

 necessary to note that the liver, as will be shown in another 

 place, is not a mere preparer of a digestive fluid, and that 

 bile seems rather to be formed in connection with a blood- 

 purifying process in the liver, than as an aid to digestion. 

 The bile is, however, undoubtedly of great service in tho 

 absorption of oils. In dogs in which the gall ducts have 

 been shut off from the intestine, and the bile allowed to 

 escape by an external opening, the operation is followed by 

 greatly impaired power of absorbing oils. Indeed, bile is 

 the strongest soap known, ox-gall being on that account used 

 by painters to wash away oil paint; and it seems probable 

 that, by lubricating the villi, the bile assists the minute 

 globules in the emulsion formed by the pancreatic juice to 

 permeate the mucous membrane. Bile is likewise an anti- 

 septic, and prevents the putrefaction in the contents of the 

 intestine, which always takes place when its flow is pre- 

 vented. But, in addition to all this, it is to be observed 



