262 



STRUCTURE OF GLAXDS. 



a 



with thin parietes, from the 40th to the 50th of a line in 



diameter, and 

 capable of being 

 distended by air, 

 introduced into 

 the gall - ducts 

 with which they 

 are connected. 

 For this struc- 

 ture we have the 

 assurance of ana- 

 logy, from what 

 we witness in the 

 constitution of 

 Fig. 265. Lobules of the liver, superficially si- the other glands, 



tuated, divided horizontally ; a, o, intralobular 



veins ; b, b, clefts between the several lobules, in 



which cellular tissue, minute subdivisions of the 



hepatic ducts of the vena portse and hepatic artery, 



are included ; the middle portion of each lobule is 



here in a state of congestion. After Kiernan. 



XPS 

 f^PK, 



mlf$ 



t^Sf 



Vi] 



llasr 

 it^JT 



mode of evo- 

 lution of the li- 

 ver itself, and 

 the structure of 

 the organ in the 

 invertebrate se- 

 ries of animals ; 

 in fact, if we 

 turn to the cray- 

 fish and common 

 garden snail, we 

 find the precise 

 structure in ques- 

 tion. In the 

 cray-fish the li- 

 ver consists en- 

 tirely of small 

 Fig. 266. The intralobular plexus of biliary ves- p i n ted cseca, 

 sels, as figured by Kiernan although the injection Clustered ' ijW 

 of these vessels was not so complete as it is here re- 

 presented ; d, d, two lobules divided across, with the grapes ; m 

 ramifications of the hepatic vein, a, a, the twigs of snail it is made 

 which perforate their centres ; b, b, b, b, branches up of blind, 

 of the hepatic duct, as they take their rise from the rounded termi- 

 plexus of biliary vessels, which are here injected, and -, vpsirlps 



surround the uninjected portions of the substance of 1-1 i ' 



the lobules, d, d; c, cellular substance between the wmcn may 

 lobules. blown up with 



>gfe 



*%iiM N oi 



