540 



GENERAL CHARACTERS OF REPTILES. 



ment of the respiratory apparatus, a remarkable anomaly ; one 

 of their lungs being so little developed, that we can often scarcely 



ANATOMY OF COLVBER. 



I, tongue and glottis ; as, oesophagus, divided at of to show the heart, &c. ; i, stomach ; 

 f ', intestine ; cl, cloaca ; an, anus ; /, liver ; o, ovary ; 6, eggs ; t , trachea ; p, principal 

 lung; p', undeveloped lung; tt, ventricle; c, left auricle; c", right auricle ; ag, left 

 aortic arch ; ad, right aortic arch ; a. a, ventral aorta ; ac, carotid arteries ; v, vena cava 

 superior ; re, vena cava inferior; vp, pulmonary vein. 



perceive it ; whilst the other acquires very considerable dimen- 

 sions (Fig. 315). 



480. Reptiles are all cold-blooded animals ; that is to say, 



