CHTLIFICATION. 151 



trituration, furnished, not merely with a hard cuticle, as in 

 birds, but also with numerous rows of teeth, of various forms, 

 answering most effectually the purpose of dividing, or grind- 

 ing into the minutest fragments, all the harder parts of the 

 food, and thus supplying any deficiency of power in the jaws 

 for accomplishing the same object. Thence the aliment, 

 pr*operly prepared, passes into the cavity appropriated for 

 its digestion, which constitutes the true stomach.* In the 

 lower part of th's organ a peculiar fluid secretion is often in- 

 termixed with it, which has been supposed to be analogous 

 to the bile of the higher animals. It is prepared by the 

 coats of slender tubes, termed hepatic vessels, which are 

 often of great length, and sometimes branched or tufted, or 

 beset, like the fibres of a feather, with lateral rows of fila- 

 ments, and which float loosely in the general cavity of the 

 body, attached only at their termination, where they open 

 into the alimentary canal. t In some insects, these tubes are 

 of larger diameter than in others: and in many of the or- 

 thoptera, as we shall presently see, they open into large re- 

 ceptacles, sometimes more capacious than the stomach itself, 

 which have been supposed to serve the purpose of reservoirs 

 of the biliary secretion, pouring it into the stomach on those 

 occasions only when it is particularly wanted for the com- 

 pletion of the digestive process.^ 



* It is often difficult to distinguish the portions of the canal, which cor- 

 respond in their functions to the stomach, and to the first division of the in- 

 testines, or duodenum,- so that different naturalists, according 1 to the views 

 they take of the peculiar office of these parts, have applied to the same ca- 

 vity the term of chyliferous stomach, or of duodenum. See the memoir of 

 Leon Dufour, in the Annales des Sciences Naturelles, 5i. 473. 



f The first trace of a secreting structure, corresponding to hepatic vessels, 

 is met with in the dsfcrias, where the double row of minute lobes attached 

 to the csecal stomachs of those animals, and discharging their fluid into these 

 cavities, are considered by Cams, as performing a similar office. The floc- 

 culent tissue which surrounds the intestine of the Hohthuria, is probably, 

 also, an hepatic apparatus. 



$ A doubt is suggested, by Leon Dufour, whether the liquid found in 

 these pouches is real bile, or merely aliment in the progress of assimilation. 

 Ann, Sc, Nat. ii. 478. 



