1906.] Liver Cells to the Blood-vessels and Lymphatics. 



489 



Results of our own Observations. 



We have been unable to find any perivascular lymph spaces in the lobules, 

 but have seen appearances which might be mistaken for such ; in every such 

 case we have been able to satisfy ourselves that the injection is inside the 

 wall and not between it and the liver cells. 



We agree with Minot that the blood-vessels have more the character 

 he assigns to sinusoids than that of capillaries. In injection preparations 

 the distended blood-vessels follow the outlines of the liver cells, and at places 

 penetrate for some distance between them. This appearance was described 

 by Garter, and by J. W. and E. H. Fraser. In the liver of the bird it is 

 extremely well marked (fig. 9), but it is present in all livers we have 

 examined. In injected preparations of the livers of fcetal rabbits the blood- 

 vessels appear as large sinuses closely investing the liver cells and passing 

 between them. Wherever the injection penetrates between the cells it shows 

 a broad connection with the injection mass in the lumen of the blood-sinus 

 and gradually tapers to a fine point between two liver cells (figs. 4 to 9). 

 There is no evidence of any wall lying between the intercellular injection and 

 the lumen of the blood-vessel. 



The cells which occur at intervals along the blood-vessels may be divided 

 into two classes, which agree with those described by Kupffer. Small nuclei 

 with very little protoplasm are found closely applied to the liver cells ; they 

 have the general appearance of endothelial cells, and their long axes are 

 parallel to the direction of the vessel which they line. One of these cells 

 is shown in fig. 3. They do not appear to form a continuous sheet of 

 endothelium, and long intervals frequently occur between them. 



The other class is composed of much larger cells with comparatively large 

 amounts of protoplasm. They, vary in shape, and in section may appear 

 as long, pointed cells or star-shaped with several processes. Each cell 

 contains a nucleus which is usually elongated, but varies in size and shape 

 in different cells. Occasionally a large nucleus projects into the lumen of 

 the vessel and lies with its base closely applied to the wall of a liver cell 

 (fig. 3). The protoplasm round the nucleus is sometimes difficult to see, in 

 which case it looks as if nucleus alone were present, but in other cases the 

 protoplasm is large in amount and granular. We take it that these are 

 Kupffer's cells, but they frequently have the appearance described by Browicz, 

 of projecting into the lumen of the vessel, and in thin sections may even seem 

 to be lying free. Fig. 3, which is a drawing made from a section of liver of 

 cat stained with eosine and methylene blue, shows two such cells. Eed blood 

 corpuscles are often seen lying between the processes of these cells and 



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