PULMONARY VESSELS. 329 



One case of this kind has ah-eady been mentioned in the 

 account of the liver,* where the Vena Portarum terminated in 

 the Vena Cava, below the liver, without entering into it. 



Another very remarkable instance of peculiar arrangement is 

 to be seen in a preparation now in the University of Pennsyl- 

 vania, in which the Inferior Cava, instead of opening into the 

 lower part of the right auricle, passes behind it, in the tract of 

 the Vena Azygos, and opens into the Superior Cava, in the 

 place where the Vena Azygos usually communicates with that 

 vessel, receiving the Intercostal Veins in its course. 



In this preparation, the Hepatic Veins communicate directly 

 with the right auricle, at its lower part ; the middle and left 

 hepatic veins forming one trunk before they enter, and the 

 right vein passing in singly.f 



Of the Pulmonary Arteries and Veins, see Plate I. page 241. 



Those portions of the Pulmonary artery and veins which are 

 distinct from the lungs may be described very briefly. 



It has been already observed, that the pulmonary artery 

 arises from the left and most anterior part of the basis of the 

 right ventricle, and proceeds thence obliquely backwards, 

 inclining gradually to the left side for about eighteen or twenty 

 lines, when it divides into twe branches, which pass to the two 

 lungs. This course places it under the curve of the aorta : for 

 that great vessel passes over the right branch of the pulmonary 

 artery, and the right side of the main trunk of it, in such a 



* See note to p. 97, of this volume. 



t The foregoing preparation was made by the present editor in 1814, since 

 which two other anomalous cases have occurred to him. 



1819. Case 1st. The ascending cava passed into the thorax on the left side 

 of the spine, and getting as far as its upper part, was joined there by the trunk 

 of the internal jugular and subclavian of the left side. It there passed across 

 the vessels of the arch of the aorta and joined with the descending cava. The 

 vessels of the liver entered the heart at the usual place, in the lower part of the 

 right auricle. 



1820. Case 2d. The trunk formed by the junction of the internal jugular and 

 subclavian of the left side, instead of taking its usual course, passed down ver- 

 tically, before the left branch of the pulmonary artery and before the left auri- 

 cle, then making a slight curve between this auricle and the diaphragm joiued 

 ■with the ascending cava. — h. 



28* 



