SECRETORY APPARATUS OF THE LIVER. 
479 
their contents into the cavity of the duct ; this view accords with that of M. Henle, 
as to the arrangement of the ultimate secreting elements of the mammary, lachrymal 
and salivary glands, which he believes to consist of vesicles filled with nucleated 
particles, seated on the closed extremity of a terminal branch of the duct. 
It has now been shown that the secreting process commences in the centre of the 
lobule, and terminates at its margin along the line of the surrounding duct ; but we 
have yet to consider the mode in which its progress is conducted, how the secreted 
material makes its way from cell to cell. This is a subject of which we have but little 
knowledge ; the existence and nature of organic forces are as yet declared to us by 
their effects only ; we can however refer to several examples, which exhibit a pro- 
cess similar to the one we are now considering ; in cartilage, we believe the nutrition 
of the greater part of its substance to be performed by the nucleated cells which lie 
scattered throughout it, and attract from each other the nutrient fluid originally 
received from the blood ; in the less perfect varieties of bone, crusta petrosa, the 
process is nearly the same. Mr. Goodsir, in his description of the human placenta, 
has stated that a double layer of cells is interposed between the maternal uterine 
sinuses and the umbilical capillaries of the foetus, which are probably concerned in 
the transmission of fluids from one to the other ; and lastly in plants, we know that 
there are several parts of their structure through which fluids are transmitted, which 
consist of nothing else but a congeries of cells. Some observations may now be 
mentioned which elucidate in some measure this function of transmission as per- 
formed in the liver. Having examined a considerable number of these organs, I have 
generally noticed that those which had been secreting most actively, which presented 
the least appearance of retained bile or oil, exhibited the linear arrangement of the 
cells most perfectly ; while in cases of disease, where the secretion has been more or 
less retained or suppressed, the disposition of the cells has been much more irregular. 
It would therefore seem that the linear arrangement bears a relation to the integrity of 
the secreting process*. In examining isolated portions of rows of cells, where their 
outlines could be clearly distinguished, it has been very evident that they were 
differently disposed with regard to each other ; some were seen to overlap the next 
in order, and the cell-wall could be clearly traced all round ; others were flattened 
at their apposed edges, and simply united without overlapping; in others again the 
septum formed by their apposed walls was so indistinct that it could only just be 
discerned ; and in a few instances it has appeared to be wholly or in part wanting, 
so that the cavities of the cells were fused together. Occasionally a globule of the 
secretion has been observed in the act of passing from one cell to the next, but in the 
greater number of instances there has not been any marked difference in the contents 
* In the case of a patient who died from the effects of dilatation of the heart, the liver was found to present 
the “ nutmeg” appearance in a very marked manner, the cells mostly containing particles of bile of a bright 
yellow colour ; their arrangement was remarkably plexiform, so as to give the appearance of a close network 
with small light interspaces. 
