104 



THE CIRCULATION. 



forming by their union two large trunks, called the supe- 

 rior and inferior vena cava, discharge their contents into 

 the right auricle, whence we supposed the blood to start 

 (% 33). 



Structure of tlie Valves of the Heart. 

 It will be well now to consider the structure of the 

 Fig. 34-* 



* Fig. 34. The right auricle and ventricle opened, and a part of 

 their right and anterior walls removed, so as to show their interior. \. 

 i, superior vena cava ; 2, inferior vena cava ; 2', hepatic veins cut 

 short ; 3, right auricle ; 3', placed in the fossa ovalis, below which is 

 the Eustachian valve ; 3", is placed close to the aperture of the coronary 



