FlG. 76. A DIAGRAMMATIC FIGURE SHOWING THE ARRANGEMENT 

 OF THE BLOOD VESSELS IN A CHICK EMBRYO AT THE END OF THE 

 FIFTH DAY OF INCUBATION. THE AMNION HAS BEEN REMOVED, AND 

 THE VITELLINE VESSELS CUT SHORT A LITTLE DISTANCE FROM THE 



EMBRYO. (After Marshall.) 



A, dorsal aorta. A 3 , A 4 , A 6 , third, fourth, and fifth aortic arches of the 

 right side, lying in the first, second, and third branchial arches respectively. A A, 

 allantoic artery. AB, basilar artery. AC, carotid artery. AH, caudal artery, 

 the terminal portion of the dorsal aorta. A L, lingual artery. AP, pulmonary 

 artery. A V, vitelline artery. El, auditory vesicle. RA , right auricle. RS, 

 sinus venosus. R T, truncus arteriosus. RV, right ventricle. TA, allantois. 

 VA^ allantoic vein. VB, anterior cardinal vein. VC, posterior cardinal vein. 

 VD, Cuvierian vein. VE, meatus venosus. VH, efferent hepatic vessel. VI, 

 posterior vena cava. VJ, jugular vein. VO, afferent hepatic vessel. VV^ vitel- 

 line vein. 



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