510 



MANUAL OF HISTOLOGY. 



are but sparely found in the gall bladder and inferior portion of the 

 cystic duct, but make their appearance in the upper portion of the canal, 

 and ductus choledoclms and hepaticus (fig. 505, a). In the wider passages 

 of the latter, with a diameter of about '7 mm., is to be found another series 

 of simple csecal formations, some of tubular, some of flask-like figure. In 

 that network of fine passages situated in the transverse fissure of the liver 

 they occur also (b) ; likewise in those ducts arranged around the larger 



branches of the portal vein 

 within their sheaths, and 

 finally in the lateral twigs 

 given off from the branches 

 lying in the longitudinal 

 fissure of the organ. These 

 appendages have by some 

 been supposed to be im- 

 perfectly developed mucous 

 glands, but by the majority 

 of histologists they are re- 

 garded now as blind rami- 

 fications of the bile ducts 

 or receptacles for the bile 

 (Beale, Koelliker, Riess). 

 According to this last view 

 they would be numbered 

 among the vasa aberrantia 

 of E. H. Weber. We 

 understand under this 

 name, passages of '02-0'7 

 mm. in diameter, which 

 leaving t-he substance of 

 the liver, undergo sub-divi- 

 sion into smaller branches' 

 in a connective - tissue 

 stroma. They are to be 

 found in the ligamenium triangulare sinistrum, and the fibrous bridge 

 across the inferior vena cava. They are partly disposed in a retiform 

 manner, and some of them terminate with bulbous dilatations. 



The numerous lymphatics of the liver consist of a series of superficial 

 vessels, and another situated more deeply communicating with the first. 



The first lying in the deepest layer of the peritoneal covering of the 

 organ, is made up of a complex unlaminated network of fine canals, whose 

 larger efferent vessels pass off in various directions. Those on the convex 

 surface of the liver take their course towards the ligaments of the organ, 

 and do not meet with lymphatic glands until their entrance into the 

 thorax. Those from the under surface of the viscus, on the other hand, 

 empty themselves into lymph nodes in the neighbourhood of the trans- 

 verse fissure and the gall-bladder. 



The deeper lymphatic vessels enter with the portal veins, hepatic 

 arteries, and bile ducts, into the interior of the organ, enveloped in a 

 fibrous prolongation of Glisson's capsule, and follow all the ramifications 

 of the latter canals. In their course they invest the branches of both 

 ducts and blood-vessels with a delicate network of tubes, and arrive thus 

 at the periphery of the lobules, still in the form of distinct vessels. Here 



Fig. 505. a, bile-duct glands from the hepatic duct of the 

 human liver; 6, injected twig of the biliary plexus of the 

 fossa transversa (after Henle). 



