82 



COMPAEATIVE ZOOLOGY. 



Indeed, it is common for Fislies to disgorge the indigesti- 

 ble parts of their food, and some, as the Carp, send the 

 food back to the pharynx to be masticated. Tiie stomach 

 is iisnally bent, like a siphon ; but the intestine is nearly 

 straight, and without any marked distinction into small 

 and large. Its appendages are a large liver and a rudi- 

 mentary pancreas. 



In the Amphibians, as the Frogs, the digestive apparatus 

 is very similar to that of Fishes ; but the two portions of 



the intestine can be more readily 

 distinguished. The Reptiles gen- 

 erally have a long, wide gullet, 

 which passes insensibly into the 

 stomach, and a short intestine 

 (about twice the length of the 

 body) very distinctly divided into 

 small and large by a constric- 

 tion." The vegetable -feeding 

 Tortoises have a comparatively 

 long intestinal tube; and the 

 Serpents have a slender stomach, 

 but little wider than the rest of 

 Fib. «.— Anatomy of a Cephniopod the alimentary canal. 



(dirtsrum): a, tentacles; 6, masti- m. , i r ai /^ jm 



catoTy apparatus; o.eye; d, sali- The Stomach of the CrOCodllc 



vary gland; e,i,e,vo>,sgauglia:/pi4^m j COmpleX than 



/.oesophagus; jy, internal shell, or \ o J r 



"ciitiie-boue;" A, stomach; i, in- any hitliorto mentioned. It re- 



testine ; k, anns ; I, fimnel ; m, '' 



ink-bag; «, ovary; o, oviduct; p, scmbles that of the Cuttle-fish,but 



•Miver"; r, gill contained in the j« ,.i, ^ •! • i 



bnuichiai chamber; s, branchial offcrsa Still more Striking analogy 



• heart, «, systemic heart; », mantle. ^^ ^]^^ gizzard of a Bird, having 



very thick walls, and the muscular fibres radiating pre- 

 cisely in the same manner, so that, in this respect, the 

 Crocodile may be considered the connecting link between 

 Eeptiles and Birds." In Crocodiles also the duodenum, 

 with which the intestine begins, is first distinctly defined. 

 Into this part of the intestine the liver and pancreas, or 

 sweet-bread, pour their secretions. Furthermore, in tiie 



