878 THE LIVER. 



size which are not surrounded with lobules. These aberrant ducts, as they 

 might be called, were described by Ferreiu and by Kieriian ; they anastomose 

 together in form of a network, and are accompanied by branches of the 

 vena portse, hepatic artery, and hepatic vein. 



Structure of the gall-bladder. Besides the peritoneal investment, the walls 

 of the gall-bladder are formed of two distinct layers of tissue constituting its 

 areolar or fibrous and its mucous coats. 



The areolar coat is strong, and consists of bands of dense shining white 

 fibres, which interlace in all directions. These fibres resemble those of 

 areolar tissue. In quadrupeds recently killed the gall-bladder contracts on 

 the application of a stimulus ; and in the larger species, as well as in man, 

 muscular fibres of the plain variety have been found mingled with those of 

 the areolar coat. These fibres have principally a longitudinal direction, but 

 some run transversely. Their nuclei are indistinct. The areolar coat forms 

 the framework of the organ, and supports the larger bloodvessels and lym- 

 phatics. 



The mucous coat, which is generally strongly tinged of a yellowish-brown 

 colour with bile, is elevated upon its inner surface into very numerous small 

 ridges, which, uniting together into meshes, leave between them depressions 

 of different sizes and of various polygonal forms. This structure gives to the 

 interior of the gall-bladder an areolar aspect, which is similar to what is 

 seen on a smaller scale in the vesiculae seminales. These areolar intervals 

 become smaller towards the fundus and neck of the gall-bladder ; and at 

 the bottom of the larger ones, other minute depressions, which may be seen 

 with a magnifying lens, apparently lead into numerous mucous recesses or 

 follicles. The whole of the mucous membrane is covered by columnar 

 epithelium, and it secretes an abundance of viscid mucus. 



At the places where the neck of the gall-bladder curves on itself, there 

 are strong folds or projections of its mucous and areolar coats into the 

 interior. 



In the cystic duct, the mucous membrane is elevated internally in a sin- 

 gular manner into a series of crescentic folds, which are arranged in an 

 oblique direction, and succeed closely to each other, so as to present very 

 much the appearance of a continuous spiral valve. When distended, the 

 outer surface of the duct appears to be indented in the situation of these 

 folds, and dilated or swollen in the intervals, so as to present an irregularly 

 sacculated or twisted appearance. It is of importance to note the influence 

 of this valve in causing the retention of biliary concretions in the gall- 

 bladder. 



Among the monographs which give an account of the structure of the 

 liver, the following may be specially mentioned : Kiernan, in Phil. Trans- 

 actions, 1833 ; Theile, in Wagner's Handworterbuch d. Physiologie, p. 308 ; 

 Rainey on the Capillaries of the Liver, in Microsc. Journal, I. p. 231 ; 

 Handfield Jones, in Phil. Transactions, 1849 and 1853; Budge, in Miiller's 

 Archiv, 1850 ; Beale, Lectures in Medical Times and Gazette, 1856, and 

 "On some points in the Anatomy of the Liver," in Philos. Trans. 1856 ; 

 Chrzonszczewsky, in Virchow's Archiv, XXXV. p. 153, 1866 ; Frey, in 

 Zeitsch. f. Wissensch. Zoologie, March, 1866. 



THE BILE. 



The bile, as it flows from the liver, is a thin greenish yellow fluid ; but that which 

 remains in the gall-bladder becomes darker, more viscid, and ropy. It contains as 

 adventitious particles mucus and epithelium corpuscles, but no hepatic cells. The 



