448 A, B. MAOALLUM. 



of gold chloride, and to the subsequent treatment with formic 

 or acetic acids. Osraic acid, although useful in the case of 

 meduUated nerve-fibres, is of no value for demonstrating the 

 finest non-medullated fibrils. 



Here a few words are necessary concerning the structure of 

 the cytoplasma. In figs. 3, 4, 5, 6 it is represented as a net- 

 work with thickened nodal points. It must be admitted that 

 it does not always appear in such a regular arrangement. The 

 meshes are often much larger and round as if occupied by fat 

 droplets. Often also the trabeculse thin out toward the peri- 

 phery of the cell, so as to be nearly indistinguishable. The 

 specimens of Necturus from which these preparations were 

 made were caught early in March, 1885, and consequently 

 there was but a small amount of fat in the hepatic cells. The 

 appearance presented in the figures is a normal one, for 

 chromic acid material with hematoxylin or aniline dyes show a 

 similar arrangement. Flemming^ believes in the arrangement 

 of the cytoplasma in threads throughout the cell, but doubts if 

 these form a network such as Klein^ describes. Structures, 

 however, like those drawn in figs. 5 and 6, leave hardly any 

 doubt as to the occurrence of a reticulum. 



The Nerves of the Human Liver. 

 In sections of the liver treated successfully with gold chloride 

 the tissues immediately about the interlobular and central 

 veins take a rose-violet or blue-violet colour. These strongly 

 coloured fields, observed with a low-power objective, seem to 

 consist wholly of violet-coloured fibres, but when more highly 

 magnified the latter, which are commonly arranged in bundles, 

 are seen to constitute but a small part of the interlobular 

 tissue, or of that about the central vein, there being between 

 the bundles a quantity of connective tissue coloured light violet 

 or red. The thickest fibres are of about 0*0035 mm. in diameter. 

 Each bundle is composed of a varying number of fibres, and is 



1 ' Zellsubstanz, Kern, und Zelltheilung,' Leipzig, 1882, p. 28. 



2 "Observations on the Structure of Cells and Nuclei," this Journal, vol. 



