Skeleton of a large Water Beetle, as seen from below. B, the head. D X>, the prothorax. 



F F, the mesothorax. If JJ, the metathorax. a a, fore legs, e e, fore wings, ii, middle 



legs, o o, hind wings, u u, hind legs, j, antennae. 



CHAPTER I. 



OF THE ORGANS OF SUPPORT, OR SKELETON. 



THE Physiology of Insects is the account of how they are 

 made : there are in every animal four essential elements, 

 matter, motion, sensation, and mind. 



Matter is inert it does not move by its own powers ; it 

 is tangible the touch ascertains that it resists : matter in 

 animals has various degrees of consistency ; convenience, 

 however, has suggested its division into solid and fluid. 



