LIVER 



271 



region which possibly represents the rudiment of the liver (Fig. 219). 

 In Craniates the outgrowth develops into a large vascular and 

 glandular organ, which gives rise to bile, and remains in communi- 

 cation with the intestine by means of one or more bile-duds ^ 



Fig. 217. — Viscera of Lacerta agilis. (From the ventral side.) 



Oe, cesophagus ; J/, stomach ; MD, small inte.stine ; ED, large intestine ; L, 

 liver ; OB, gall-bladder ; Pn, pancreas ; Bl, urinary bladder ; Lg, L(f, 

 the two Inngs, with their network of vessels ; //, heart ; Ci, postcaval, Tr, 

 trachea. 



(Figs. 206, 209, and 216-218). It is united to the body- wall by a fold 

 of the peritoneum, and varies considerably in the number of its 

 lobes : in Mammals there may be as many as six or seven {e.g., Dog, 

 Weasel). We may nevertheless fix upon a ground-form consisting 



' The single-lobed liver of the Lamprey undergoes a histological retrogression 

 (fatty metamoi-phosis) after transformation. The tubuli disappear, the cells 

 become filled with fat, and the gall-bladder and bile-duct become atrophied. 



