EEPTILES. 213 



liver, but mostly free and close to the concave surface of the liver ; 

 in some serpents only, where the liver lies very forward, the gall- 

 bladder is found at a distance from it, and placed more backward. 

 Sometimes the cystic duct arises from the hepatic duct ; sometimes 

 the hepatic ducts pass immediately into the gall-bladder [ductus 

 hepatico-cystici). Mostly the cystic duct unites with the hepatic 

 duct to form a common ductus clioledoclms^ . 



The jpancreas, constantly present in reptiles, is often large, 

 but varies in form in the different genera. The number also of 

 the ducts differs ; usually there is only one ; in the Nilotic cro- 

 codile there are two, which penetrate the intestinal canal below 

 or behind the gall-ducts ; in the European fresh-water tortoise 

 there are, according to Bojanus, two. In some serpents also the 

 ducts are two or even more ; in Python the poncreas is divided 

 into many distinct lobes, each with its separate duct ; these ducts 

 fall, like veins, into larger trunks which penetrate the intestinal 

 canaP. 



The spleen in this class is always present, generally small, 

 and often situated close to the stomach, although it varies in this 

 respect as also in that of its size. In the serpents it is mostly 

 situated in front of the pancreas and in close connexion with it^. 



Productions or duplicatures of the peritoneum, by which the 

 intestinal canal is supported and attached, and which bear the 

 name of mesentery, are always present, though in various degrees 

 of development. The productions of the peritoneum, on the con- 

 trary, which hang from the stomach or the intestinal canal, the 

 omenta, are wanting, although two appendages of the peritoneum 



^ In some crocodiles, as Alligator sclerops, the cystic duct continues distinct from 

 the hepatic duct, and the two open into the duodenum by separate apertures; see 

 W. Vrolik in the Bijdragen tot de natuurkiondige Wetenschappen, i. biz. 167, PI. 1 11, 

 fig. I. 



2 DuvEKNOT, Ann. des Sc. nat. xxx. p. 123. 



3 According to Meckel {System der vergl. Anat. iv. s. 3/1) the spleen is wanting 

 in serpents, a statement confuted by Duvernoy 1. 1. pp. 113 — 121. According to 

 Aristoteles, Baktholinus and Perbault the chameleon should have no spleen. 

 Some years ago this was also asserted by G. R. Treviranus {Die Ersclieinungen und 

 Gesetze des organischen Lebens, I. 1831, s. 345). He however himself described a small 

 dark body, apparently the same with that which W. Vrolik considers to be the spleen 

 (Opmerkingen over den Chameleon, biz. 57), and which has also been observed by myself. 

 It lies under and behind the stomach between the laminre of the mesentery. 



