STRUCTURE OF TURTLES. 



175 



heatj which is so considerable that our internal temperature 

 constantly maintains itself at the height of 98° F. 



Smaller Circulation. Through the Lungs. 



Pulmonary 



Artery. 



Ilight Auricle 



Left Ventricle. 



Heart. 



Aorta. 



Veins convey- \\ ^$$!^-j:-~-^%%////l Arteries con- 



ingdull purple v£\ \$^z--'-<'J---*Z^/ // veying aerated 



blood to the iV\^^"^-^-^--^vCSv or scarlet blood 



heart v!o$5?— Z---~ — <SZZ7/ from the heart. 



Greater Circulation. Through the Body. 



Theoretic Representation of the Circulation m 

 Mammals and Birds. 



But the turtle's heart is differently formed, consisting, as the 

 annexed theoretic representation shows, of but one ventricle and 

 two auricles, so that a mixed, or only half aerated blood circulates 



;, ^^ 

 &>. 



Right Auricle -^^^mM^ZZZ ' Left A,,ricle - 



Single Ventricle iff- -^x*S?!?-— ^y\ Heart. 



Venae cavse W 1 ^ [ 



Veins. 



Theoretic Representation of the Circulation in Reptiles. 



throughout tbe body, which naturally produces a torpidity of the 

 whole vital process. Besides, the lungs of the reptiles are inca- 



