THE CIRCULATION. 149 



pulmonary artery issuing from it, to the lungs. Here it 

 suffers changes which will be discussed further on, the re- 

 sults of which are, that the dark venous blood is changed 

 into the light arterial blood, which is then, by means of the 

 pulmonary veins, returned to the left side of the heart. 

 Here it flows into the left auricle, at once proceeds to the 

 left ventricle, and by means of this powerful ventricle it is 



Fig. 69. DIAGRAMMATIC REPRESENTATION OF THE CIRCULATION OF WARM-BLOODED 



ANIMALS. 



o, auricles; v, ventricles; P, pulmonary capillaries; (7, systemic capillaries; a, a, aorta; 

 v, c, vena, cava; a, p, v, p, pulmonary artery and vein. 



forced out through the issuing aorta and sent over the body. 

 Carried by arteries it finally reaches the capillaries of the 



