H2 PROTOPLASM 



taken, I only gave quite a cursory consideration to the 

 matter. I will, therefore, only state briefly that the dark 

 line of demarcation sometimes appears rather thicker, 

 and may then itself appear to have a meshed structure ; 

 it should, however, be taken into consideration, that slightly 

 oblique sections through the limiting lamella might produce 

 appearances of this kind, although I do not wish to deny 

 their reality altogether off-hand. 



Just as we are able to demonstrate an alveolar layer at 

 the surface of the liver cells, so it is not infrequently pos- 

 sible to convince oneself that a radially arranged layer of 

 meshes occurs round the nuclei. 



The sectional width of the meshes of these liver cells I 

 am inclined to estimate at about 1 //,. 



Sections of pieces of rabbit's liver prepared in a corre- 

 sponding manner showed the reticular structure of the 

 protoplasm in the same way and very beautifully. In 

 addition to cells, of which the protoplasmic framework was 

 pale and finely structured, exactly as has just been described 

 in the frog, there also occurred some with a considerably 

 coarser and hence much more distinct structure. In these 

 cases the trabeculae of the mesh work were also much thicker 

 and darker than usual. Photograph IX. gives a fairly good 

 representation of such cells. I contented myself at the time 

 with ascertaining the meshwork structure of the protoplasm 

 of these cells, without entering more especially into the 

 numerous points of detail still to be solved. 



9. Epithelium of the small Intestine of Lepus cuniculus 



Pieces of the small intestine of the rabbit, after being 

 hardened in picro-sulphuric-osmic acid and strongly stained 

 in iron-hsematoxylin, show the structure of the epithelial 

 cells very beautifully in thin sections. As in all cells of 

 similar structure, we have also to deal here with a mesh- 

 work modified into a longitudinally fibrillar structure with 

 numerous strongly staining granules lodged in the nodal 

 points. As far as I investigated the structure of the 

 protoplasmic framework, it agreed entirely in essential 



