CIRCULATION 



207 



Fig. 114. — Diagram to show the general plan of the circulation in mammals. 

 I, Left ventricle; 2, aortic arch; 3, dorsal aorta; 4, postcaval vein; 5. rij^ht 

 auricle; 6, right ventricle; 7, pulmonary artery; 8, pulnvmary veins (the pul- 

 monary veins open into the left auricle which in turn opens into the left ventricle). 

 The order of the numbers 1-8 indicates the course taken by the blood in com- 

 pleting a circuit of the systemic and pulmonary circulations. 10, the thoMfic 

 (lymphatic) trunk; 11, precaval vein. Dig., The digestive tract; UiJ^.V ., 

 hepatic portal vein; Liv, liver; P, lung. . ^ 



I 



