THE LIVER. 



533 



sible. Every transition may be traced from these well-marked forms to 

 ordinary cells with a few minute drops or a single somewluit larger one; 

 and, in fact, these less fatty cells occur to a certain extent in almost 

 every body ordinarily subjected to examination, so that if their absence 

 in animals were not kept in mind, their occurrence, at least to a small 

 amount, might be regarded as normal. Tiie same may be said with 

 respect to the pigment molecules (Fig. 220 b). When these are very 

 abundant they are certainly pathological ; but when few, they can only 

 be regarded as a slight deviation from the normal state. They are small, 

 hardly exceeding 0-001 of a line, of a yellow, or brownish yellow color; 

 their chemical reactions are identical with those of the coloring matter of 

 the bile as it occurs in the intestinal canal, inasmuch as they are not 

 altered in color by nitric acid, nor dissolved by caustic alkalies. 



The hepatic cells are so arranged in the islets as to form a network 

 by the simple apposition of their flat surfaces, without the assistance of 

 any foreign connecting intermediate substance or investing coat. The 

 simple or branched columns of hepatic cells, which are almost always 

 to be found among scraped off particles of the liver, and to which Henle 

 drew attention (AUg. Anat., p. 903), are nothing but fragments of the 

 hepatic cell-network, whose elements do not cohere very firmly. Taken 

 altogether, the network of every hepatic islet presents more rounded 

 meshes at the periphery, while in the centre they are constantly dis- 

 posed radially, whence, in a transverse section through the interlobular 

 vein, long ramified columns of hepatic cells are seen stretching from the 

 latter on all sides and 

 uniting by short lateral 

 anastomoses, so that the 

 intermediate meshes ap- 

 pear like narrow elonga- 

 ted clefts. The hepatic 

 cohcmns consist of 1-3, 

 more rarely of 4-5 rows 

 of cells, have a diameter 

 of 0-01-0-015 of a line 

 on the average, 0*006- 

 002 of a line in extreme 

 cases, and are generally 

 cylindrical or prismatic, 

 but not at all regularly 

 so; their surfaces are arched, plane, or, in some localities, depressed, 

 and have rounded or sharp angles. The meshes of the hepatic cell- 

 network correspond with the diameters of the capillaries and of the larger 



Fio. 221. — Hepatic cell-network, 6, and finest ductus interlobulares, a, of Man, after nature, 

 the union of the two, diagrammatic ; magnified 350 diameters : c, vascular spaces. 



Fi?. 221. 



