STRUCTURE OF GLANDS. 



263 



air from the biliary ducts. If we farther examine the liver 

 of the larva of the water-newt (fig. 268, B) we see distinct 

 clusters of csecal ca- 

 nals, or round ter- 

 minal cells, like is- 

 lets, surrounded by 

 subdivisions of the 

 hepatic vein ; but 

 these csecal canals, 

 at all events, are not 

 thin-walled cells ; 

 they are almost as 

 compact as the acini 

 of the fully formed 

 liver of the highest 

 mammal. 



ELEMENTARY PARTS 



OF GLAXDS. 



T& A9f\ Tli ^* ^"' ^ ew f ^ree lobules of the liver 



L^ 4-0. 1 He pro- cut across> the centre of each occupied by the 



per substance of ramifications of the intralobular (the hepatic) 



glands is not formed vein, a, a, a. b, b, b, Branches of the vena 



by or out of the or- P ortae which course in the spaces between the 



dinarv cellular sub- loli)ules surrounding these and constituting the 



j intralobular veins. Numerous ramuscles pene- 



tance, t ; by and trate into the interior of the lobules and anasto . 



from other more m0 se with the intralobular or hepatic veins. The 

 or less distinctly rounded and oval interspaces or islets between 

 cellular elements these vessels are filled or possessed by the bi- 

 This anatomical hary vessels (fig. 266), and form the acini of 

 truth is particu- Malplghu After Kiernan< 

 larly evident in the liver (fig. 263, A). Here the parietes 

 of the acini consist entirely of compact, irregularly rounded 

 or angular cells, of about 1 -200th of a line in magnitude. 

 The cells of the liver enclose a distinct clear nucleus and 

 a yellowish-coloured molecular matter in their interior. 

 The cells are like the stones of a piece of ancient masonry, 

 irregularly applied to one another. Externally, where the 

 blood-vessels play around them, fibres of cellular tissue are 

 added. An epithelial covering of flat tessellated cells first 

 makes its appearance in the larger branches and trunks 

 of the gall-ducts. In other cases, as in the glands of 

 the stomach, for instance ( 329), the substance of the 



