DEVELOPMENT OF THE ELASMOBRANCH LIVER 



365 



10 mm. long and in figure 8 ^, a cross section of the same 

 specimen. 



The effect of the enlargement of the left omphalo-mesenteric 

 vein upon the liver anlage has already been described in part and 

 will be considered farther in describing later stages. Passing 

 along the left side of the median hepatic pouch or the common 

 bile duct it pushes this structure to the right and shifts the left 



V.ompti.l 



V. Sukinh 



V omph-T- 



Fig. 17 Frontal section of the liver and mid gut region of an Acanthias erhbryo 

 13 mm. long (H.E.C. 226). X 40. L.hep.p., lateral hepatic pouch; M.g., mid 

 gut; M.hep.p., median hepatic pouch; S.v., sinus venosus; V.omph.l., left omphalo- 

 mesenteric vein; V.omph.r., right omphalo-mesenteric vein; V.subint., subintes- 

 tinal vein. 



hepatic pouch or left hepatic duct anteriorly and laterally. This 

 process is shown in an early stage by figure 17. At the same time 

 the vessel upon encountering the left segment of the anterior and 

 expanded part of the median hepatic pouch breaks up into several 

 trunks which pass below and above the obstruction. One of 

 the larger trunks passes through the dorsal part of the vertical 

 cleft between the right and left anterior tubule groups or hepatic 



THE AMERICAN JOURNAL OF ANATOMY, VOL. 14, NO. 3 



