PARTS OF ANIMALS, IV. v. 



ink ; and though this is an effect due to necessity, 

 like the discharge of urine in the others, yet Nature 

 makes good use of this residue at the same time 

 for the animal's defence and preservation. 



The Crustacea as well, that is, both the Crabs and 

 the Caraboids, have the two front teeth, and between 

 the teeth they have the tongue-like flesh, as has 

 already been stated ^ ; and immediately next to the 

 mouth they have a gullet which is quite small com- 

 pared with the animal's size ; and immediately after 

 that the stoniach ; and on this the Carabi and some 

 of the Crabs have another set of teeth, since the 

 upper ones do not masticate the food sufficiently. 

 From the stomach a simply formed intestine runs 

 straight to the vent where residues are discharged. 



These parts are present in every one of the Testacea 

 as well, more distinct in some, less in others. They 

 are more clearly marked in the larger animals. 

 Take the Sea-snails. These have (1) as stated al- 

 ready, the teeth, which are hard and sharp, (2) the 

 fleshy object in between them, similarly to the 

 Crustacea and Cephalopods ; (3) the proboscis, as 

 already mentioned,'' something between a sting and 

 a tongue ; (4) immediately after the mouth is a sort 

 of bird's crop, and (5) after that the gullet ; (6) con- 

 tinuous with that is the stomach, and (7) in the 

 stomach is what is kno\vn as the mecon"; and (8) at- 

 taching to this is an intestine : this intestine begins 

 directly from the mecon. This residue (the mecon) 

 appears to be the most tasty piece in all the Testacea. 

 The other creatures that have spiral shells (e.g. the 



« At 678 b 10. 



" At 661 a 15 ff. 



* The hepatopancreas or liver ; see above, 679 a 9. 



l2 323 



