82 NATURAL HISTORY. 



species of renewal by molting or casting off their shells. 

 The senses of insects are very acute, namely, those of 

 smelling, hearing, and feeling ; the latter especially is 

 well developed, as may easily be remarked in those fam- 

 ilies of insects which, like the ants, live in communities, 

 and seem, by their exercise, plainly to understand each 

 other. If an insect is deprived of. its antennae or feelers, 

 it loses all relationship with others of its kind ; a plain 

 proof that the sense of touch is the communicating bond 

 between the individuals of the race. The eyes of insects 

 present, in their wonderful arrangement, food for study. 

 They are found to consist of a compound mass of hexa- 

 gonal facets, which go to form the simple eye, giving to 

 it, when seen through a magnifying glass, the appearance 

 of the seed receptacle in the sunflower, for, as each one 

 of these capsules is fitted with its seed, so is each one 

 of these facets a distinct cornea. These eyes are immove- 

 able, and covered in a remarkable manner with a dark- 

 brown pigment, which is scarcely to be distinguished 

 from the genuine color of the insect. Many of the races 

 have, conjointly with this compound eye, a simple one, 

 termed ocella, which is movable, as, for instance, those 

 of the Crustacea. The number of legs in the true and 

 perfectly-developed insect is six, the number of wings 

 two or four ; nevertheless, in the spider and crab races, 

 eight feet are usually found, and oftentimes more. The 

 growth of the genuine insect is developed only by the 

 metamorphosis it undergoes, and after passing through 

 several stages, is perfected at once when the chrysalis fly 

 emerges from the cocoon. The butterfly begins its life 

 fully grown ; spiders and crabs attain perfection by a 

 regular growth. 



The manner of life maintained by this class of animated 



