84 Anatomy of the Rabbit. 



termination, the vermiform process, being dorsal in position and 

 directed for the most part backward. It may be observed at this 

 point that in their vascular supply the more typical divisions, 

 namely, the transverse and descending colons, have arterial branches, 

 respectively, the middle and left colic arteries, comparable to those 

 of man ; while on the other hand the right colic relation, on account 



Fig. 44. The heart and lungs from the ventral surface; ad, 

 right atrium; ao, aorta; ap, pulmonary artery; as, left atrium; 

 d, right superior caval vein; i', i", left and right inferior lobes 

 of lung; 1, aortic ligament; m', m", middle lobes; ml, medial 

 lobule of, right inferior lobe; s', s", superior lobes; tr, trachea; 

 vd, right ventricle; vp,' pulmonary veins; vs, left ventricle. 



of the great complexity of its parts, is represented by a large 

 number of vessels, branches of a common ileocaecocolic trunk. 



THE RESPIRATORY SYSTEM. 



In all air-breathing vertebrates the lungs (Fig. 44) are paired 

 sacs which arise embryonically as ventral outgrowths of the digestive 

 tube, and are secondarily connected with the outside of the body 



