isos THE AMERICAN MONTHLY [October, 
which conducts between the pyloric stomach and the ‘ liver,’ and is the out- 
let of the liver, the ‘ common duct,’ or the ‘ hepatic duct.” This duct may 
be followed, if sufficient care is exercised, into the lobes, and it is found to 
branch into three tubes, one of which runs to the anterior lobe, another to 
the median or lateral lobe, and a third to the posterior lobe. These ducts are 
lost among the tubes, which will be found to be hollow, and into which they 
will be seen to open. Examination thus shows the‘ liver’ to be an organ which 
consists of three lobes, communicating by ducts with a single common duct 
on each side, which opens into the pyloric stomach. It also shows that the 
three lobes do not communicate by ducts with each other, and that there is 
only one common duct leading away from the ‘ liver’ which leads into the 
alimentary canal. The most obvious ‘ relation’ of the organ is with the ali- 
mentary canal by the ‘ hepatic duct,’ but it is not independent of the other 
bodily systems, for it is connected with both the nervous system and the blood 
system ; but the connections are too difficult of demonstration to come within 
the range of our present purpose. 
It is because of this relation of the organ to the alimentary canal that it 
has received the name of ‘ liver’ from most writers, a name which has be- 
come so firmly fixed that it will probably be retained, though it is not to be 
understood that the organ is the equivalent in any sense of the liver, as we 
know that organ in vertebrates. The organ appears to represent both the 
liver and the pancreas of vertebrates, so far as its function goes, and the 
name ‘ hepato-pancreas’ which has been applied to it would be a better 
name if it had the authority of usage which belongs to the term ‘ liver.’ It 
is in deference to this usage that I shall continue to call the organ a liver 
though it is quite as much pancreas, functionally, as liver. 
3. Minute anatomy and histology.—It would be conducive to clear- 
ness if histologists would make a distinction in language between ‘ minute 
anatomy ’ and ‘ histology,’ referring to cell structure and tissue structure un- 
der histology, and to finer arrangement of tissue in an organ by the use of 
the term minute anatomy. The two ideas are quite distinct. We shall pro- 
ceed to consider the structure of the ‘ liver’ as revealed by the study of sec- 
tions in both of these lights :—first, the study of the arrangement of the 
various parts, then the fine cell structure of each part. For the former pur- 
pose figure 1 of plate ix must be closely examined; it is a representation 
of a characteristic cross-section of the posterior lobe of the liver. It is 
selected because it shows in a single slice more of the features common to 
most of the sections than any other single section. 
On first examination this section is very probably nearly without meaning 
to an untrained observer of sections ; to the practised observer it shows at once, 
when viewed with the benefit of the knowledge of the organ, derived from 
a study of its gross anatomy, the plan of structure of this organ, many of 
the parts of which it is composed and the manner in which they are put to- 
gether, with perhaps something of the structure of each part. Such a view 
is obtained with a low power (46 diameters) under the compound micro- 
scope. The parts seen in the section (figure 1) are :— 
(1.) A thin boundary line (G. m.) which follows the contour of the organ 
very closely, it is the capsule of the gland. 
(2.) Star-shaped clear spots (J.,1.,M.,& C.), surrounded bya belt of nucle- 
ated cellular matter, which is bounded by a sharp contour line, scattered 
through most of the space inside the capsule of the gland; these are cross- 
sections of the tubules. 
(3.) Other clear spaces (B.) not star-shaped but elongate, and bounded by 
a belt of cellular matter with nuclei, these spaces in some cases communi- 
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