PAHTS OF ANIMALS, IV. v.-vi. 



character of both. Those that have no sting in front 

 have a sense-organ of that sort behind the teeth. 

 After the mouth, in all insects comes the intestine, 

 which is straight and simple right up to the residual 

 vent. (Sometimes, however, it has a spiral in it.) 

 And some there are which have the stomach next 

 after the mouth, while from the stomach runs a 

 twisted intestine ; this gives the bigger and more 

 gluttonous insects room for a larger amount of food. 

 Of all these creatures the grasshoppers are the most 

 peculiar. In them the mouth and tongue are united 

 so as to make one single part, and through this they 

 draw up their nourishment from fluid substances as 

 through a root. All insects take but little nourish- 

 ment ; and this is not so much because they are 

 small as because they are cold. (Heat needs nourish- 

 ment and quickly concocts it ; cold needs none.) 

 This is most marked in the grasshoppers. They find 

 sufficient nourishment in the moisture which the air 

 deposits ; so do the one-day creatures which occur 

 around the Black Sea. Still, they live only for the 

 space of a day ; whereas the grasshoppers live for 

 several, though not many, days. 



Now that we have spoken of the internal parts of 

 animals, w^e must go back and deal with the remainder 

 of the external parts. We had better begin with the 

 creatures of which w^e have just been speaking, and 

 not go back to the point where we left the external 

 parts. This will mean that we take first those which 

 need less discussion, and that will give more time for 

 speaking of the " perfect " animals, i.e. the blooded 

 ones. 



VI. Insects first, then. Though their parts are not external 

 numerous, insects differ from one another. They all 



' 3U 



PARTS OF 



BLOODLESS 



ANIMALS. 



