AND PHYSIOLOGY. 



235 



417. Blood-Vessels . — The arrangement of Blood- Vessels 

 is very diverse, since one portion of them breathe by gills and 

 another by lungs, while frogs in their early condition are fur- 

 Fin. 235. 



Carotiil 

 Artery. 



Arches of ^ 

 the Aorta. > 



Intestines. 



Circulatory Apparatus in the Lizard. 



417. Why are blood-vessels arranged differently in many of the reptiles? 



