162 



INSECT TRANSFORMATIONS. 



respiration, like the gills of fish, though there are 

 several other spiracles in other parts of the body com- 

 municating with the large convoluted windpipes. 

 The anal apparatus is surrounded with five hard, 

 moveable, triangular pieces, all fringed with hairs, 

 which it can open or shut at pleasure. The largest 

 of these pieces is placed above, while the two smallest 

 stand at the sides, and two of the middle size below. 

 When they are shut close they form a blunt cone.* 



a, grub of a dragon fly; b b, the lody laid open and magnified 

 to show the windpipes; c, the pumping apparatus shut; d. the 

 same open; e, head of the insect. 



It may not be out of place to take notice here of 

 another singular structure in the same species of lar- 

 vae, which is probably unmatched in the insect world. 

 In the larvae of most insects, the under-lip is small 

 and inconspicuous, but in those of the dragon-flies, 



* De Geer, ii, 666, and Reaumur, vi, 393, &c. 



