450 CEPHALOPODA. 



In other genera this laminated viscus is represented by a csecal 

 appendage to the intestine, placed precisely in the same situation ; 

 and, on opening it, its internal surface is found to be increased by 

 a spiral lamella that winds closely upon itself from one end to the 

 other. In such cases it is near the apex of the spire that the 

 bile is received from the liver, so that in all essential particulars 

 this spiriform viscus is precisely analogous to the laminated cavity 

 of the Nautilus. There can be little doubt that this apparatus re- 

 presents a capacious duodenum, and that it is by the extensive 

 surface afforded in its interior that the nutritious portions of the 

 food are separated ; as neither the gizzard nor the intestine itself 

 present an organization adapted to such a purpose. With respect 

 to its other uses Professor Owen remarks, that its reception of 

 the biliary secretion renders it in some measure analogous to a 

 gall-bladder ; but most probably its chief office is to pour into 

 the commencement of the intestinal canal a fluid which is neces- 

 sary for the completion of digestion, so that, like the pyloric ap- 

 pendages of fishes, it might be considered to be the representative 

 of a pancreas. 



The remainder of the intestine is a simple tube, which, after one 

 or two turns upon itself, mounts up to the base of the funnel, into 

 which it opens ; and thus allows the excrement to be ejected to a 

 distance from the body. 



(492.) The liver (fig- 210, z) is of very great bulk when com- 

 pared with the rest of the digestive apparatus. In Nautilus it is 

 divided into four distinct lobes, which are themselves made up of 

 numerous lobules of an angular form, each being invested with a 

 very delicate capsule. On removing the capsule every lobule is 

 seen to be composed of numerous acini, which with a needle may 

 be readily separated into clusters connected by the ramifications of 

 their excretory duct. In other genera, such as Octopus, wherein 

 these acini have been minutely examined, they have proved to be 

 delicate cells or secerning cseca wherein the bile is elaborated. 

 The excretory canals derived from all the lobules of the liver 

 unite by repeated anastomoses, and thus form two main trunks, 

 which ultimately join, and pour the biliary secretion into the lami- 

 nated or pancreatic cavity (y). 



In the Cephalopods, as in all the Mollusca, the bile is separated 

 from arterial blood supplied by large vessels derived immediately 

 from the aorta ; no system of veins analogous to the vena porta of 

 higher animals being as yet developed. 



