Franklin P. Mall - 273 
terminal hepatic branches are very irregular, often come to the surface 
of the liver and sometimes anastomose. There is much difference of 
opinion regarding the statements given in the above sentence, but anyone 
who will take the trouble to make a few good celloidin corrosions will 
find them correct. 
Branches of the fifth order of the portal vein are .15 mm. in diameter ; 
those of the sixth order .05 mm. The interlobular veins are about half 
the diameter of the intralobular and twice as numerous. Even these 
Fic. 37. Photograph of the terminal branch of the portal tree. X 2. 
often branch before they give rise to capillaries. While the hepatic vein 
receives capillaries down to veins marked S in Fig. 32, the portal twigs 
of the same figure give off capillaries only at their extreme tips. Unless 
the extreme tips of the hepatic vein, Fig. 32, C, are taken as centers of 
the lobule and clusters of the tips of the portal vein, J, as centers of the 
portal units will these two correspond in number. The relative number 
is shown in Fig. 38, which is from a free-hand model in clay from a 
celloidin corrosion. The protruding points, C, mark the position of the 
tips of the central veins. The tracing, Fig. 35, shows the same. 
Not only are the centers of the portal unit marked by the tips of the 
