mi Of nn. i 



duodenum, \vhicli receiver thetwoducttu hepatiei. The evagination 



gradually increase- to ;i long Dingle .-.iM:il. the bile, duel <.j ductu-* 

 eholedochu>, (lie result of which |T lhat the whole liver IB 



farther removed from its source of origin. 



r.y an evagination either of the ductus choledochua \- of ne of 



the two dactus hepatici, the ,/^// A/^A/,V \\ith it- due: m i> 



eMablished. In Man it urigef from tin- due t us chled. >chr 

 present as early M tin- second month. 



'I'he network <f hepatic cylinder-., wlii.-li are BOmetimefi hollow, 



sometimes solid, is metamorphosed in two in 



On,- part becomes the excretory duct > (thrductus hilift-ri). In 

 the caeefl in which the lirpatic cylinder.^ are at lir>t >olid, they i 



to become hollow and to arrange their oella into a cul.ical -r cylin- 

 drical ej.ithelium around the luini'ii. In this process some of tin- 

 branches of the network must degenerate. Kor. whereafl all li-|.:iti,- 

 rylindeis at tirst communicate wit h one another hy n.eans of , 

 tomosrs. this is. as KOI.I.IKKU remark.-, no longer the case in the 

 adult, except at the outlet of the liver (Leberpforte), where the 

 well-known network of bile-ducts exi 



The remaining part of the network furnishes the secretory par. -n- 

 chyma of liver-cells. The character of a netlike tubular <rland, 

 which becomes so evident durinir development, i> to he recoirni>rd 

 even in the fully developed or^an in the , aso of the low 

 brates, the Amphibia and Keptiles. The tubules of the </. 

 which were from tbe beginning hollow. >ubxr.piently exhibit an 

 exceedingly narrow lumen, which i- dem.n>trable only by means of 

 artitic-ial inaction, and which in CTOSfl >ect ion is Mirrounded by three 

 to five liver-cells. Through their manitold anfl 'hey produce 



an extraordinarily fine network, the > m all meshes of which are filled 

 up by a network of capillary blood-vessels, together with a very small 

 amount of connective >ub>t.ince. 



In the higher Vertebrates (Birds, Mammal>. Man) the tubular 

 structure of the gland >ulei|uently l;ec< : '!i>picuu> and 



the liver acquires a complicatnl >tructur-. information (oncernini: 

 the details of which i- given in of histol 



There arc three things which, from a developmental point of view, are not to 

 be lost sight of : first, the capillaries of the bil. 



tion of the primitive hepatic cylin-:- 1 l>y only 



two liver-cells, which an* very hiyi' and tlake-like ; thirdh. i out 



evaluations between and even into the liver-cells t: 

 greater complication is brought about in tbe arrangement of the fine biliary 



