THE LIVER SECRETION OF BILE. 



473 



the medium-sized ducts remains columnar, passing in the smaller ducts into 

 the tessellated variety, suddenly becomes spheroidal, or assumes the form of 

 the true secreting cell. The tubes, of the diameter of g^th of an inch and 

 larger, present many little saccular dilatations of the coats, the openings of 

 which, according to Dr. Beale, are regularly arranged in two rows or lines 

 on opposite sides of the ducts; and besides these are numerous small, irreg- 

 ular, and anastomosing canals, which run obliquely in the coats of the ducts, 

 and ultimately open into their cavities. These tubes and cseca may be re- 

 garded as accessory gall-bladders, in which the Bile, secreted and stored up, 



FIG. 169. 



Section of an injected liver from the Rabbit. The sh-uder and dark biliary ducts are seen to be 

 arranged in the form of a plexus, each of the nu'shes of which incloses a biliary cell with oue or two 

 nuclei. The much wider capillaries are also shown. 



comes into intimate relation with a fine plexus of capillaries, and may per- 

 haps undergo further elaboration. In regard to the mode of termination 

 of the finest biliary ducts it appears from the observations of Bering and 

 others, 1 that when injected the canals existing between the large secreting 

 cells, form a close plexus, the meshes of which appear to inclose the hepatic 

 cells, though in reality the lines of injection follow the spaces between the 

 large secreting cells (Beale). In the Rabbit these canals run exclusively, 

 and in Man and the Dog in by far the greatest number, not along the angles, 

 but between the opposite surfaces (Fig. 171) of two adjacent cells, dividing 

 their surfaces sometimes into two equal halves and at others unequally. 

 The blood capillaries, on the other hand, chiefly run in the angles formed 

 by the junction of three or more cells. According to Bering, the biliary 

 canals and passages do not possess any membrana propria, their walls being 

 formed by the hepatic cells themselves, which succeed suddenly to the flat- 

 tened polyhedric cells of the smaller biliary ducts, but MacGillavry and 

 Chrzonsczsczewsky maintain that they have proper walls, the bile-secreting 

 cells lying (Fig. 170) to their outside, though this is perhaps illusory, the sup- 

 posed vascular wall being only a thickening of the cell-wall. Both Weber 

 and Asp, from injections with gamboge dissolved in spirit (Weber), and 



1 Strieker's Manual of Histology, vol. ii, 187'.', Syd. Soo. Translation. See also 

 MacGillavry, Sitz.-ber. d. k. Akad. zu Wien., Bd. 1, 18(34. Keichert, Ecichert's 

 Archiv, 1866, p. 734. Irminger and Frey, in Kolliker's Zeitschrift, 1806, p. 208. 

 Oscar Wyss, in Virchow's Archiv, 1866, April, and Chrzonsczsczewsky 's paper ab- 

 stracted in Humphry and Turner's Journal, vol. i, 1867, p. 146. Koiliker, Hand- 

 buch der Gewebelehre, 18G7. Eberth, Centralblatt, 1866, No. 57, nnd Sitz.-ber. d. 

 Wien. Akad., Dec. 1866. A. Mayer, Strick. Mod. Jahrbucher, 1872, p. 133, and 

 Asp, 1. c. 



31 



