486 Drs. Herring and Simpson. Relation of the [May 31, 



those shown by Kupffer, but insists that they do not form a syncytium, but 

 are well defined cells which occur inside the blood-vessels. He also con- 

 siders that the blood has a very close relationship to the interior of the 

 liver cells, and argues against the presence of perivascular lymph spaces in 

 the liver lobules. 



Eeinke(51), in the same year, described a fine membrane which surrounds 

 every liver cell like a capsule, and is composed of connective-tissue cells, 

 some of which resemble Kupffer's cells, while others are more like the tendon 

 cells seen in the tail of the mouse. He also believes in the existence of the 

 perivascular lymph sheath described by Disse, and thinks that the connec- 

 tive-tissue cells take part in the formation of its wall, and are probably 

 endothelial cells lining it. 



Little has been said about the lining of the capillary walls by most of the 

 authors who have described Kupffer's cells as extravascular connective-tissue 

 cells. 



Eanvier (50), in 1885, described the capillary walls as composed of a 

 granular and very thin sheet, in which nuclei occur at intervals ; the latter 

 are flattened, with long axis parallel to the long axis of the vessel, but with 

 a pronounced relief on their internal surfaces. Eanvier could find no cell 

 margins, and explains the absence of impregnation lines after using silver 

 nitrate in the liver by assuming that endothelial cells are lacking, and that 

 the cells which form the walls of the capillaries are embryonic in character 

 and form a syncytium of protoplasm enclosed by two homogeneous sheets 

 containing nuclei at intervals. 



Eanvier's views and the later ones of Kupffer are very similar: both 

 believed that the walls of the capillaries are formed by a syncytium in which 

 there are nuclei but no separate cells. Kupffer showed that the amount of 

 protoplasm round the nuclei varies in amount, and that it has active phago- 

 cytic properties. Other observers regarded Kupffer's cells as extravascular 

 connective-tissue cells, as Kupffer himself did at first. Browicz, on the other 

 hand, assigned to them an intravascular position. 



Berkley (5), by the employment of a modification of Golgi's method, found 

 two kinds of perivascular cells in the liver of the rabbit, and Dogiel(16), by a 

 similar method, described cells investing the capillaries with their branches. 



Many observers, from His onwards, have described fine connective-tissue 

 fibres between the capillary walls and liver cells in the lobules. They are 

 demonstrated for the most part by special stains only, and received from 

 Kupffer the name of " Gitterfasern," a term which Oppel (47) revived in 

 1891. Oppel employed a method of staining by silver nitrate, and described 

 radial fibres passing from interlobular connective tissue to central vein, and 



