163 DR. E. KLEIN. 



stated that the substance of the liver cells of frogconsistsof ahyaline 

 ground substance — paraplasma — and of a granular-fibrillar con- 

 tractile " protoplasma/' With reference to the liver cells of mam- 

 malian animals, I can fully confirm that observation, finding that 

 their substance is composed of a minute network, in whose 

 meshes is included a hyaline substance ; we have here what we 

 mentioned on so many previous occasions, an intracellular network 

 of fibrils,and in this an interfbrillaroTintestitial\ij3linesnhsi?iT].ce. 

 As has been noticed by many observers, the substance of the liver 

 cells appears when examined under many different conditions — 

 fresh in saline solution, aqueous humor, or macerated in iodised 

 serum, solution of bichromate of potash or Muller's fluid, especially 

 when hardened in spirit, chromic acid, or Muller's fluid — of a '^ uni- 

 formly granular" character. This "uniformly granular^' aspect is 

 due to the very close nature of the intracellular network, as I ex- 

 plained on several previous occasions. In the liver of guinea pigs, 

 the portal vein of which had been injected with a 2 per cent, solu- 

 tion of Briicke's Berlin blue, then hardened in spirit and stained in 

 carmiu or hsematoxylin, I find (a) in many acini the liver cells 

 composed of a uniform, beautiful and open network of fibrils and 

 membranes, in connection, through the nuclear membrane, with a 

 similar network pervading the nucleus itself. Next to cells of 

 this kind I find [b] such in which the network, although its 

 pauts are still distinct, is somewhat closer, and it requires a 

 higher power to distinguish it so clearly as in the former. And 

 lastly, I trace these to (c) cells in which the network is so close 

 that its constituent fibrils cannot be made out. The cell sub- 

 stance appears uniformly and densely " granular.'^ The gradual 

 transition from cells of the nature of a to those of d and c leave 

 no doubt that the uniform " granulation" is due, as mentioned 

 before, to the very close condition of the network. In fig. 20 

 I have represented liver cells in which the intracellular network 

 is seen of the character mentioned, sub. d, i.e. medium grade of 

 closeness. . 



The liver cells, in which the meshes of the network are 

 comparatively widely distended, are considerably larger than 

 those whose substance appears densely " granular," and this is 

 easily intelligible, if we remember that the distinctness of the 

 network is due to the distension of its meshes. Whether in the 

 course of functional activity the liver cells show such differences 

 of the network, as we mentioned on several previous occasions 

 (mucous glands, Brunner's glands, intestinal epithelium, &c.), I 

 am not in a position positively to assert, although I have noticed 

 certain facts which lead me to believe that also in the liver-cells 

 a difference of the appearance of their network corresponds to 

 a difTerent state of function. Thus, for instance, I have found 



