HISTOGENESIS OF THE LIVER 



287 



of the blood spaces of selected sections have been measured 

 from a series of livers of selachian embryos. Eight sections were 

 selected for measurement from each liver. To secure sections 

 representing about the same relative planes in each specimen 



Fig. 12 Frontal section through the tubules arising from the ventral surface 

 of the pars hepatica medialis of an Acanthias embryo 15 mm. long (H.E.C. 230). 

 X 150. Hepatic cell nuclei are shaded with vertical lines, nuclei of mesenchymal 

 cells drawn in outline. A single vascular twig is seen in cross section above the 

 largest hepatic tubule. 



the following method was employed. The liver was considered 

 as divisible into three parts, as represented in figure 13. The 

 first segment (A to B, fig. 13) consisted of that part of the Uver 

 anterior to the foremost part of the curved cystic duct. The 

 second segment (B to C) extended from the cystic duct to the 



