THE ANATOMY 0¥ A SIX MM. PIG EMBRYO 



103 



permanent trunk of the vitelline artery (Fig. 103). The right subcardinal is 

 connected with the Uver sinusoids through a small vein which develops in the 

 mesenchyme of the phca venae cavse (caval mesentery) located to the right of the 

 mesentery (Fig. 112). This vein now carries blood direct to the heart from the 



Aortic arch i Seessel's pocket 



Aorlu arch 2 \ 1 ^=^- _^-— / thmits 



Phalanx 



Tlniioid 

 Aorlu Itch ■? 



Noloc'lio} d 

 Aortic arch 4 



Aortic arch • 

 pulmonary a 



JoS 



Esophagus 

 lOy 

 Trachea - 



lICl, 



R. lung 

 III 



112 



Stomach' 



ri3 



Caliac artery 



JJ4 

 Ventral pancrea: 



Dorsal pauer< 



Gall bladder 

 L. umhi 



-"Int. carotid artery 



106 



Hypophysis (pharyngeal 



lobe) ' 



Optic recess 



Telencephalon 

 Ventral aorta 



Metancpfiric antage 

 "4 



L umbilical artery 



nastomosis between 

 dorsal aorla 



Ulantoic stalk 

 'orsal aorta 

 hrie duct 



Artery to mesonephros 

 Caudal limb of intestinal loop 



Ceph 



Dorsal aorta 



Mesentery 



Fig. 105. — Reconstruction of a 6 mm. pig embryo in the median sagittal plane, viewed from the 

 right side. The numbered heavy lines indicate the levels of the transverse sections shown in Figs. 

 106-117. The broken lines indicate the outline of the left mesonephros and the course of the left um- 

 bilical artery and vein. The latter may be traced from the umbilical cord to the liver where it is sec- 

 tioned longitudinally. (Original drawing and reconstruction by Dr. K. L. Vehe). X 16.5. 



right posterior cardinal and right subcardinal, by way of the liver sinusoids and the 

 right vitelline trunk (common hepatic vein). Eventually the unpaired inferior 

 vena cava forms in the course of these four vessels. (For the development of the 

 inferior vena cava see Chapter IX.) 



