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gelatin to shrink. Such sections show that the blue fluid has entered the 
lymphatics at the center of the portal unit. The specimens are more in- 
structive when the injection is stopped just as the first lymphatics are 
filling with the colored gelatin. By following the larger portal veins and 
lymphatics back into the liver substance it is found that the interlobular 
connective tissue is entirely filled with blue where the lymphatics are in- 
jected, but only partly colored blue when they are not. In other words, 
the blue extravasates from the capillaries at the center of the portal unit 
and invades the connective tissue to reach the beginning of the lym- 
phatics, when of course it is carried rapidly from the liver. The nearest 
course from the capillaries to the lymphatics is at the center of the portal 
unit where the amount of connective tissue is small, for as colored fluid 
begins to enter lymph channels only the tips of the capsule of Glisson 
are entirely tinged, while the larger portal spaces are encircled by a 
zone of color. Furthermore, it is found that in certain instances, where 
the injection was too brief, that the blue did not enter the lymphatics at 
all. In such specimens all of the interlobular spaces are surrounded by 
a zone of colored gelatin which does not enter the main lymph channels. 
A successful injection of the lymphatics is illustrated in Fig. 54. The 
granular blue enters the capillaries of the lobule, c, with ease, and from 
them the liquid blue is filtered through the capillary walls to enter the 
perivascular lymph space, pul. This space communicates at the center 
of the portal unit directly with a large lymph space between the liver 
cells and the capsule of Glisson, which may be called the perilobular 
lymph space. These spaces, pl/, in turn communicate with the lymph 
radicals. 
It is further shown by injecting the liver with aqueous Prussian blue 
that there are no capillaries between the periphery of the lobule and the 
interlobular connective tissue. The liver cells come in contact with the 
capsule of Glisson. An injection of brief duration with blue gelatin soon 
fills the perilobular lymph spaces, so that it appears as if all groups of 
liver cells at the periphery of the lobule were separated from the inter- 
lobular connective tissue with capillaries. In case cinnabar granules 
are mixed with the blue a few of these granules are found in the peri- 
vascular and perilobular lymph spaces, the openings in the walls of the 
capillaries being large enough to allow a few of the smaller granules to 
escape. As the injection is extended the blue invades the connective 
tissue spaces from the lymphatic radicals more and more until a lymph 
channel is reached, when of course it rapidly fills all of the larger ducts. 
Were there a direct channel from the perilobular lymph spaces the blue 
