NATURAL THEOLOGY. 



167 



[The figure represents the two sides of the heart separated : 

 that to the left of the figure, but on the right side of the body, con- 

 taining the venous blood which must pass through the lungs to 

 serve the purposes of the economy ; and that on the left side, con- 

 taining arterial blood, which is sent out into the body. Man, and 

 all animals of warm blood, have the whole mass of blood passin-;; 

 through the lungs, and a double heart, as here represented, each 

 consisting of a vein, an auricle, a ventricle, and an artery. Tho 

 arrows point out the course of the circulation.] 



