408 PROCEEDINGS OF THE CANADIAN INSTITUTE. 
around the walls of the vein leaving but little room for other struc- 
tures than the gall-ducts and hepatic arteries. In the finer interlo- 
bular septa picrocarmine reveals very little connective tissue. 
The arrangement of the blood vessels in the liver is, on the whole, 
the same as in the higher vertebrates. There are, however, minor 
differences. The interlobular veinlets, before they pass into the 
radial capillaries, are closely gathered together to form as it were a 
wall to separate two neighbouring lobules which are thereby sharply 
defined. The course of the radial capillaries from the central vein 
outwards is very irregular. The spaces enclosed by two adjacent 
radials and their transverse branches, instead of being uniformly 
quadrilateral.as in higher vertebrates, are more or less rounded. 
The different gall-ducts are lined with an outer fibrous and an 
inner epithelial coat. The fibrous layer is formed of connective tis- 
sue fibrils and plain muscle fibres, the latter situated inside the for- 
mer, which passes into the differently arranged scanty connective 
tissue surrounding the duct. Staining with picrocarmine easily 
reveals this arrangement. The inner or lining coat of epithelium 
consists of a single layer of short cylinder cells. They are slightly 
granular, and their nuclei are placed near the bases of the respective 
cells. A peripheral wall is present. As the ducts become more 
finely branched these cells become columnar, then oval; at the same 
time the fibrous layer loses its connective fibrils, those of the muscu- 
lar coat becoming much decreased in quantity and finally vanishing. 
When the connective tissue is absent but the muscular fibrils still 
present, the epithelium becomes scale-like, forming, when the muscle 
fibres vanish, a thin wall for the lumen of the gall capillary. I 
have not succeeded in following them to their terminations in the 
hepatic cylinders, but believe that they terminate, as Hering and 
others describe, by their epithelium becoming exchanged for liver- 
cells, which here, however, do not possess a thickened border disposed 
toward the lumen of the gall capillary. 
As already stated, very little if any connective tissue enters be- 
tween the lobules, and thence the sole supporting stroma is formed by 
the blood capillaries. There is a complete absence of those cells. other 
than hepatic, which sometimes characterize the livers of higher ver- 
tebrates. Kupffer’s stellate cells, which are rendered remarkably 
distinct in other livers by methylene blue, cannot be detected here. 
