GENERAL CHARACTERS OF REPTILES. 539 



an aquatic, afterwards an aerial respiration. There are even 



Arches of A 



Super, vena cava 



Ventral Aorta" 



Pulmonary artery* 

 Inferior vena cava 



rotid artery 



^.x' Arches of aorta 

 .xRight auricle 



^.-'Ventricle 



^ Pulmonary vein 



. Brachial artery 



.--" Pulmonary artery 



-Vena porta> 

 Intestines 



FIG. 314. CIRCULATING APPARATUS OF LIZARD. 



some which retain their organs during the whole of life, and 

 which, having at the same time lungs, are completely amphibious ; 



N N 2 



