308 THE MECHANICAL FUNCTIONS. 



general form of the body, but also in the consoli- 

 dated texture of its organs, (especially of those 

 which compose its skeleton) and in the possession 

 of rigid levers, shaped into articulated limbs, 

 and furnished with large and powerful muscles, 

 from all which circumstances great freedom and 

 extent of motion are derived. To this elaborate 

 frame, nature has added wings, those refined 

 instruments of a higher order of movements, 

 subservient to a more expanded range of exist- 

 ence, and entitling the beings on which they 

 have been conferred to the most elevated rank 

 among the lesser inhabitants of the globe. 



The mechanical functions of insects scarcely 

 admit of being reduced to general principles, in 

 consequence of the great diversity of forms, of 

 habits and of actions, that is met with among the 

 innumerable host of beings which rank under 

 this widely extended department of the animal 

 creation. In these minute creatures may be 

 discovered all the mechanical instruments and 

 apparatus required for the execution of those 

 varied motions which we witness in the larger 

 animals, and which, though almost peculiar to the 

 different classes of these animals, are here fre- 

 quently united in the same individual. Insects 

 swim, dive, creep, walk, run, leap, or fly with as 

 much facility as fishes, reptiles, quadrupeds, or 

 birds. But besides these, a great number have 

 also movements peculiar to themselves, and of 



