XXVI.] 



LIVER. 



2 9 I 



difficult to get a perfect injection, but it is easy in the guinea-pig to 

 inject the large bile-ducts. They are injected from the common 

 bile-duct after ligature of the cystic duct. Sometimes it is better 

 not to clamp the cystic duct, as after the gall-bladder is full it acts 

 as a reservoir, and prevents too great pressure, causing extravasations 

 of the injection fluid. 



(a.) (L) Large Bile-Ducts. Numerous sections of these lying in 

 portal canals between the lobules. Each is provided with a fibrous 

 coat containing circular, smooth, muscular fibres, lined by columnar 

 epithelium. In the walls 

 of the largest ducts are 

 mucous glands, which 

 open into the bile-duct. 



(?>.) (H) The bile- 

 capillaries within the 

 lobules appear as a fine 

 hexagonal network of , 



blue lines between the "* BMBMBMflMW * 

 surfaces of the hepatic 

 cells (fig. 282). If cut 

 transversely, they appear 

 as mere blue specks 

 between adjacent cells. 

 They are not to be con- 

 founded with the blood- 

 capillaries, which are 

 much wider, and are 

 arranged in a different 

 way. 



(c.) The columnar epi- 

 thelium lining the interlobular bile-ducts and their fibrous walls 

 (fig. 281). 



10. Auto-Injection of Bile-Ducts. Place a piece of indigo- 

 carmine, about the size of a split pea, under the skin of the fore- 

 arm of a pithed (brain-destroyed) frog. Tie the slit to prevent its 

 escape. After twenty-four hours the whole frog will appear quite 

 blue. Kill it, rapidly remove the liver, cut it in small pieces, and 

 place it at once in absolute alcohol, which fixes the blue colour. 

 After it is hardened, cut sections and mount in balsam. 



(a.) (H) The blood-vessels are yellow, with gland-tubes between, 

 but the bile-capillaries are bine. They can be seen as blue zigzag 

 fine streaks between the cells when the tubes are cut longitudinally, 

 and as very small dots when cut transversely. A thin section gives 

 a clear view of the relation of blood-capillaries, cells, and bile- 

 capillaries. 



-B.C. 



FIG. 282. Lobule of Rabbit's Liver. Vessels aixt bile- 

 ducts injected. P.V. Portal, and H.V. Hepatic 

 vein ; B.D. Bile-duct, and B.C. Bile-capillaries. 



