AND FUNCTION OF THE LIVER. 
13 
testine and stomach are formed up to about the ninth or tenth day, the mass of the 
liver has no connection by ducts with the intestine. 
In one instance 1 obtained a very good view of the developing hepatic duct as it 
approached the liver; it was formed in a tract of cell substance, which served as a 
blastema, and was invested on its margin by some fibrous tissue ; in this the channel 
ofthe duct was excavated, which was lined by a distinct homogeneous membrane, 
and invested by a delicate transparent epithelium. Towards the hepatic extremity 
the cavity became less marked, its margin indistinct, and the homogeneous tunic less 
perceptible ; but I satisfied myself, by very careful examination, that the duct-channel 
terminated by a cul-de-sac, while the blastemous tract, as yet unexcavated, stretched 
on much further. 
In the parenchyma of the liv^er, just at the beginning of the fifth day, the formation 
of vessels and blood was very well seen; several groups of blood-globules lay in short 
channels provided with a fine homogeneous lining ; these were oval or more elongated; 
they did not appear to coalesce, but were manifestly tending to such an arrangement, 
which a few hours later had actually occurred. 
I saw no cells throwing out filamentary processes, such as Kolliker has described ; 
the channels containing the blood- globules were spaces excavated in the blastematous 
mass ; their homogeneous walls I believe to be produced secondarily, and their 
coalescence to be effected by a simple extension of their cavity. 
About the eleventh day I found the parenchyma of the liver consisting of nuclei, cells, 
amorphous and abundant oily matter; here and there in the midst of the substance 
there were seen small bright yellow particles, which were doubtless biliary matter; 
the gall-bladder also was full of green bile, the presence of which, as there was no 
trace of cysto-hepatic ducts to be seen, I cannot satisfactorily explain ; it does not 
appear to me, however, an idea to be altogether rejected, that before the hepatie 
ducts are fully developed, and have begun to eliminate bile in the parenchyma, their 
function should for a time be performed by the epithelium of the gall-bladder, which 
lies in close contact almost imbedded in the mass of the liver; the fact, at any rate, 
is, that the gall-bladder contains bile, when there is not a trace of it in the ducts, and 
when their development is yet incomplete. 
The development of the pancreas seems to be very similar in its mode to that of 
the liver, and the same plan will, I believe, be found to be followed in the formation 
of all glands. The organ consists at first of blastematous matter, imbedding nuclei 
and myriads of granular globules, which are clustered over with oily molecules. The 
sides of the mass are even, and it presents no trace of the ultimate glandular vesicles, 
which are so characteristic of its adult condition. About the same time that the 
ducts of the liver appear, those of the pancreas begin to be developed; they are not 
formed by a protrusion from the intestine, but rather seem to develope themselves on 
the spot where they are to exist. This at least is the case with the main trunks ; the 
smaller branches are no doubt formed by an extension of the cavities of the larger ones.. 
