THE LIVER. 125 



the reddish needles of bilifulvin, lately observed by Virchow, 

 ('Mittheil d. Wurzburg, Phys. Med. Ges.' I, p. 311.)] 1 



I [The view which Professor Kblliker takes of the mode of termination of the 

 hepatic ducts, can hardly be said to present any essential difference from that which 

 Dr. Handfield Jones has ably advocated in several successive papers in the ' Philo- 

 sophical Transactions' (for 1846, 1849, and 1853), and which we here subjoin in his 

 own words : 



" The liver, in all vertebrate animals, may be regarded as consisting of a secretory 

 parenchyma and of excretory ducts. 



" The size of the excretory apparatus bears only a small proportion to that of the 

 secretory. 



" These two portions of the liver are not continuous with one another, but are 

 disposed simply in a relation of juxtaposition. 



" The action of the liver seems to consist in the transmission of bile, as it is 

 formed, from cell to cell, till it arrives in the neighbourhood of the excretory ducts, 

 by which it is absorbed. This action is probably slow and very liable to be inter- 

 fered with, contrasting remarkably with that of the kidney, where a particular 

 apparatus is added to ensure completeness and rapidity of action. 



" The secretion of the hepatic cells is very liable to be retained within the gland, 

 either in the cells or in a free state. 



" This circumstance, as well as its structural relations, seem to point out the liver 

 as approximating to the class of ductless glands. 



" For the same reason it is highly probable that a part of the secretion of the cells 

 is directly absorbed into the blood which traverses the lobules" (' Phil. Trans.,' 

 1849, p. 132)." 



From an extensive series of researches in all classes of the Vertebrata, Dr. H. 

 Jones comes to the conclusion that the excretory system of the liver always terminates 

 in closed tubes. The ducts of the Sheep's liver, which in all essential particulars 

 agrees with that of Man and of the Pig, are thus described : 



II In the minutest branches (of the biliary ducts) which seem to be approaching 

 their termination, and which can sometimes be examined and isolated in the most 

 satisfactory manner, the epithelial particles are remarkably modified; they can 

 scarcely be said to exist as separate individuals, but rather their nuclei, which are 

 often large and distinct, are set close together in a subgranular or homogeneous basis 

 substance. In ducts where this condition of epithelium exists, there is seldom any 

 distinct trace of basement membrane; the margin, . though sufficiently even, yet 

 exhibiting the bulging outlines of the component nuclei ; still less is there any proper 

 fibrous coat, though the ducts may be more or less involved iu the filamentary 

 expansions of the capsule of Glisson. Ducts of this character have usually a diameter 

 of about To'ojjth of an inch ; they can sometimes be followed for a considerable distance 

 without being seen to give off any branches, or to diminish much in calibre. Their mode 

 of termination is various — several have been distinctly seen to terminate by rounded 

 and closed extremities, which have nearly the same diameter as the duct itself ; others 

 seem to lose their tubular character, their nuclei become less closely set together, 

 and the uniting substance more faintly granular and indefinite ; the duct, in short, 

 gradually ceases, losing all determinate structure. In some, of rather minute size, 

 ioos — nfefith of an inch in diameter, the exterior form remains distinct, but the canal 



