506 MANUAL OF HISTOLOGY. 



tive-substance of the gland and the walls of the vessels, appear quite 

 distinct from one another, they assume the appearance, later on in older 

 animals, of being fused into one single lamina. That this, however, is 

 probably not the case, will be seen further on when we come to consider 

 the arrangement of the lymphatic streams. 



For our acquaintance with these important points, in regard to the 

 structure of the liver, we are indebted for the most part to the exertions 

 of Beetle and E. Wagner. 



265. 



The arrangement of the ultimate radicles of the bile ducts in the 

 interior of the lobules, and their relations to the secreting cells, is a subject 

 fraught with difficulty for the microscopic anatomist, and one which for 

 a long time baffled every attempt at elucidation, owing to the imperfection 

 of the earlier methods of treatment of the hepatic tissue. It is no 

 wonder, then, that here extensive use was made of hypothesis, and that 

 many theories as to the arrangement of parts sprung up only to be aban- 

 doned again. At last success attended the efforts of some to demonstrate 

 distinctly the finest bile ducts. The first successful observers in this 

 interesting field of discovery were Gerlach, Budge, Andrejevic, and 

 MacGillavry. The results of their investigations were all very similar, 

 and our own experiences, as well as those of Chrzonszczeivslcy (arrived at 

 by means of a peculiar method of treating the hepatic tissue), are in exact 

 accordance with them. Further progress in this direction was made again 

 through the elegant demonstrations of Hering, confirmed and amplified 

 later on by Eberth. Subsequently similar passages were discovered in the 

 various racemose glands, to which we have already frequently referred 

 ( 198, 245, 255, and 261). 



The first point to be noticed, and one which has long been recognised 

 with ease, is that the ramifications of the bile ducts accompany the 

 branches of the portal vein between the hepatic lobules. From these, 



Fig. 503. Biliary capillaries from the rabbit's liver. 1. A part of a lobule ; o, vena 

 hepatica; b, portal twig; c, bile ducts; d, capillaries; e, biliary capillaries. 

 2. Biliary capillaries (6) in their relation to the capillaries of the vascular system 

 (a). 2. Biliary capillaries in their relation to the hepatic cells; a, capillaries; 6, 

 hepatic cells; c, bile ducts; d, capillaries of the blood-vessels. 



then, another set of fine thin-walled biliary canals take their rise (fig. 

 503, 1), which invest the further ramifications of the vena portae (b) with 

 delicate networks (c) in their course between the lobules. 



