96 THE BILE. 



to the lungs, in which the great pulmonary vessels are intended 

 for their function, and the bronchial arteries for their nourish- 

 ment ; and, if we are not greatly mistaken, the use of the hepatic 

 artery is similar." 



M. Simon informs us, that, after tying the hepatic artery in 

 pigeons, the bile was secreted as usual ; but after tying the vena 

 portae, none was produced. 15 A. Kaau found water injected into 

 either the vena portae or hepatic artery exude on the surface of 

 the liver q ; but this might be mere imbibition. 



From the great abundance of twigs of the vena portae which 

 are distributed in the lobules, among the original biliferous or 

 secreting ducts, and the extremely small number of arteries 

 which enter the lobules, though they run plentifully upon the 

 larger or excreting biliferous ducts, Mr. Kiernan infers that the 

 bile is secreted from the blood of the vena portae alone. 



Two instances have occurred in London, of the vena portae 

 running, not to the liver, but immediately to the vena cava inferior. 

 One is described by Mr. Abernethy, and the other is mentioned 

 by Mr. Lawrence. 8 Mr. Kiernan has examined the preparation 

 made from Mr. Abernethy's case, and found that the branches 

 of the umbilical vein were open, and communicated with the 

 hepatic artery, the blood of which, having become venous in the 

 capillaries, must have found its way for secretion to the lobules 

 by means of the ramifications of the umbilical vein, which was 

 in truth, as it always is, the vena porta?, but arose in this case 

 from the extremities of the hepatic artery alone, and not, as in 

 ordinary cases, from them and the extremities of the arteries of 

 the other abdominal viscera, by means of their veins, which unite 

 to form what is termed properly the vena portae. 



In the mollusca, there is certainly no vena portae, and the liver 

 receives its blood from the aorta. 



" The bile flows slowly, but constantly, along the hepatic duct. 

 The greater portion runs constantly through the ductus communis 

 choledochus into the duodenum, but some passes from the hepatic 

 into the cystic duct, and is received by the gall-bladder, where it 



p Edinburgh Journal of Medical Science, No. i. p. 229. This effect of tying 

 the vena portae was long ago observed. See Sb'mraerring, De C. H. Fabrica y 

 t. vi. p. 1 82. 



* Perspiratio dicta Hippocrat. 563. 



r Phil. Trans vol. Ixxxiii. 



s Medico- Chirurgic. Trans, vol. v. p. 174 



