CIRCULATION OF THE BLOOD IN MAMMALIA, AS DEPICTED IN MAN. 



The chambers of the heart and the vessels which contain arterial blood are coloured red, those 

 containing venous blood blue. The gradual division of the great arteries into smaller 

 and smaller vessels, and the origin of the great veins by the union of the smaller vessels 

 (capillaries), is shown only in the head, hands and feet. The arrows indicate the direction 

 of the blood-stream. Lu., Trachea ; Le., liver ; M., spleen ; D., intestinal vessels. For 

 the "meaning of the other letters see Section 6. 



