362 



AVES 



transverse vein so that if the head is turned around the blood can 

 still flow back into the heart through one of the jugular veins. 



Grac/iiol artery 



Srochio/ t^e/n 



Subclavian artery 



Vertebral vein 

 Vertebral artery 



■Juqulor vein 



Common carofi'd artery 



Brachial artery. 



Broctiia/ vein 



.Lett pectorof 

 arteries and veins 



__Internal mammary 

 artery and vein 



— Left auricle -. 



- J f 



Rii^tlt precavat vein y / 

 Aortic arch 

 flight auricle 

 Post cava/ vein — 



Riqtit ventricle "^ 



Hepatic veins 



Reno/ artery 

 temorot artery 



Afferent renal vein-^^=-^=S 



t^emorol vein 



Ffenal porta/ vein 



3ciafic artery 

 Renal arteries 



Dorsal aorta 



Fig. 203. Heart of pigeon. (After Parker's Zootomy. Courtesy of Macmillan and 



Co., Ltd.) 



"^Left pulmonary artery 

 Left ventricle 



—Coe/ioc artery 

 Dorso/ aorta 

 -Anterior mesenter/c artery 



■Epiijastric vein 



I/iac vein 



Afferent renai vein 



—f^emora/ artery 



Femora/ vein 

 Renal vein 



Respiratory System. — Air passes from the anterior nares or 

 nostrils through the posterior nares, pharynx, trachea, and bronchi 

 into the lungs and thence into from six to nine large air sacs. The 

 air is forced into the air sacs by passage through the air in flight 

 and out of them by wing compression. Hollow bones which render 

 them lighter in the air are found in the soaring birds. 



Voice Box. — The syrinx is a structure found at the point where 

 the trachea divides into the bronchi. A flexible valve extends 



