middle linos of tlio latter, and snspcMids the stoninoli and 

 the greater portion of tlie intestine, l)nt not the duodennm. 

 It is curious that the anterioi' two-thirds of the stomach 

 are attached to this mesenteric sheet along the mid-d(nsal 

 line, Init towards the latter third the attachment is on tlu> 

 rio-hi side, as if the stomach had l»een longitudinally 

 rotated from left to right. This mesenterj' is of coiirse a 

 double sheet of menibiane which encloses the urocyst and 

 ureter. A second, appartuitly distinct mesentery takes 

 origin over the inteinal s\irface of the liver, and is 

 attached to the duodenum and to the greater portion of 

 the succeeding intestine. The latter is therefore attached 

 to othei' parts by means of two mesenteric sheets. The 

 second mesentery described above covers over the spleen 

 and bile duct. 



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

 sists of two lobes connected bv an anterior isthmus of 

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

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

 smaller lies in the anterior and dorsal C(uner of the ocular 

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

 terior Avail (if the pericardium (Per. hg. 20). The organ 

 is suspended to the body cavity wall by the two hepatic 

 veins (1 . /i('/>. hg. 21) which penetrate the posteiior wall 

 of the ])ericardium, and by a hbrous sheet ]iassing be- 

 tween these and atta(diing the jiericardial septiim to the 

 anterior suiface 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 

 fuii'ows in Mliich tiie factors of tlie hepatic jioital system 

 r\in, and along which they can be traced foi- cousideral)le 

 distances. 



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

 between the right hepatic lobe, the right surface of the 



