Introduction. 



17 



propagate borh ways. The eggs of insects are very various 

 in form, and seldom shaped like those of birds. We have 

 here figured those of several species, as they appear ander 

 the microscope. 



When an insect first issues from the egg, it is called by 

 naturalists larva, and, popularly, a caterpillar, a grub, or a 

 maggot. The distinction, in popular language, aeems to be, 

 that caterpillars are produced from the eggs of moths or 

 butterflies ; gnibs from the eggs of beetles, bees, wasps, &c. ; 

 and maggots (which are without feet) from blow-flies, house- 

 flies, cheese-flies, &c., though this is not very rigidly adhered 

 to in common parlance. Maggots are also sometimes called 

 worms, as in the instance of the meal-worm ; but the common 

 earth-worm is not a larva, nor is it by modern naturalists 

 ranked among insects. 



There are, however, certain larvae, as those of the Cicada, 

 the crickets, the water-boatman (Notonecta), the cock- 



a, Ametabolous pupa of Cicada; 6, caterpillar of tussock moth (Laria fascdina); 

 c, larva of the poplar beetle (t'hrysomela populi); d, larva of Sinex; e, larva of the 

 common gnat. 



roach, &c., which resemble the perfect insects in form, 

 excepting that they are destitute of wings ; but in the pupa 



c 



