AND DEVELOPMENT OF THE LIVER. 
137 
margins, but no basement membrane can be detected by the most careful 
scrutiny ; it consists of nuclei set in a partly granular, partly amorphous 
basis-substance ; it issues from a quantity of fibrous tissue, which is seen at 
the upper part. 
Fig. 26. View of a terminal duct from liver of Sheep lying in an interlobular fissure ; 
it commences in a “ space,” and is seen clearly not to give off any branches 
in its whole extent, as it runs along the fissure; its extremity, I am nearly 
sure, was closed, though it was rather obscured by the investing membrane, 
under which it dipped as it approached the side of the lobule ; the length 
of this duct was ^th of an inch ; its diameter, -g^th of an inch, was nearly 
uniform throughout ; its walls were formed by nuclei of great distinctness, 
set close together in an amorphous basis-substance ; no basement membrane 
could be positively said to exist ; the hepatic duct had been injected, and a 
small mass of the colouring material was seen occupying the cavity of the 
minute duct where it lay in the interlobular “ space.” 
Fig. 27 . A minute duct, diameter of an inch, from Human liver; it lies in a 
tract of fibrous tissue, from which however it is quite distinct ; on its right 
margin there seems to be a delicate homogeneous membrane, but it ceases 
before the extremity ; this is perfectly even, and evidently has not suffered 
injury; the duct chiefly consists of nuclei set in a subgranular basis-sub- 
stance. 
PLATE XI. 
Fig. 28. A biliary duct from liver of Bullock with a lateral terminal branch ; the 
walls chiefly consist of nuclei and granular matter, and are not invested by 
a distinct basement membrane except at a ; the margin however is quite 
even ; diameter of terminal extremity g^th of an inch. 
Fig. 29. Terminal duct from Human liver, diameter i>^ch ; it is not in- 
vested by basement membrane, but consists of nuclei set in a faintly gra- 
nular basis-substance ; at its extremity it lies in contact with a group of 
hepatic cells. 
Fig. 30. View of oesophagus, stomach, liver and intestine of Chick towards end of 
6th day of incubation. CEs. oesophagus. S. stomach. L. liver ; its two lobes 
are represented. V. sac. Vitelline sac. V. duct. Vitelline duct. A. anterior 
prolongation of vitelline duct. P. posterior prolongation of vitelline duct. 
H. offset to liver, primitive rudiment of hepatic duct. 
MDCCCXLIX. 
T 
