COLUMBA. 



365 



iscentic and has a thin outer wall, its inner wall being 

 •med of the thick wall of the left ventricle. 

 The venous system consists of two complete parts — (i) 

 2 two pulmonary veins which are short and lead directly 

 )m the lungs to the left auricle, and (2) the systemic 

 stem which leads into the right auricle. There is no 



Fig. 258. — Ventral View of the Venous System of 

 THE Pigeon. {Ad nat.) 



Vertebral 



Precaval. 

 Postcaval 



Right Lobe of Liver. 



Gastric. 



nterior 



Mesenteric. 



'osterior Mesenteric, 



Renal 



External Jugular. 



Brachial. 



Pectoral. 



Aperture to Right 

 Auricle. 



Left Lobe of Liver. 



Anterior Lobe 



of Kidney. 



Renals. 



Femoral. 



Middle Lobe of 

 Kidney. 



'Sciatic. 



Posterior Lobe 

 of Kidney. 



Internal Iliac. 



Caudal. 



^he lobes of the liver are drained by hepatic veins, and the left hepatic receives a 

 long epigastric from the omentum, seen hanging down the centre. 



1US venosus, but three large veins converge together to 

 )en into the auricle. Two are paired and anterior and 

 e called the precavals ; the other one is median and 

 )Sterior, called the postcaval. 



The precavals are formed of three large veins, the 

 s;ular from the head and neck, the brachial from the 

 ng and the pectoral from the flight-muscles. The two 



