212 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



middle lines of the latter, and suspends the stomach and 

 the greater portion of the intestine, but not the duodenum. 

 It is curious that the anterior two-thirds of the stomach 

 are attached to this mesenteric sheet along the mid-dorsal 

 line, but towards the latter third the attachment is on the 

 right side, as if the stomach had been longitudinally 

 rotated from left to right. This mesentery is of course a 

 double sheet of membrane which encloses the urocyst and 

 ureter. A second, apparently distinct mesentery takes 

 origin over the internal surface of the liver, and is 

 attached to the duodenum and to the greater portion of 

 the succeeding intestine. The latter is therefore attached 

 to other parts by means of two mesenteric sheets. The 

 second mesentery described above covers over the spleen 

 and bile duct. 



The Liver (figs. 20 and 21) is asymmetrical. It con- 

 sists of two lobes connected by an anterior isthmus of 

 hepatic tissue. The larger of these lobes forms a flat cake 

 lying on the eyeless side of the body cavity, and the 

 smaller lies in the anterior and dorsal corner of the ocular 

 side, its anterior surface being in contact with the pos- 

 terior wall of the pericardium (Per. fig. 20). The organ 

 is suspended to the body cavity wall by the two hepatic 

 veins (F. hep. fig. 21) which penetrate the posterior wall 

 of the pericardium, and by a fibrous sheet passing be- 

 tween these and attaching the pericardial septum to the 

 anterior surface of the liver. This anterior surface, as 

 well as the lateral, is smooth, but the internal surface on 

 the other hand is thrown into lobules (fig. 21) by deep 

 furrows in which the factors of the hepatic portal system 

 run, and along which they can be traced for considerable 

 distances. 



The Gall Bladder (figs. 20 and 21) lies wedged in 

 between the right hepatic lobe, the right surface of the 



