INTRODUCTION. 18 



not only witli vegetable juices, but willi tbe softer parts of otber insects, 

 great numbers of whicb they seize and destroy for this purpose. The 

 soHtary and social bees {Andrenadic and Apida) live wholly on the 

 honey and jiollen of (lowers, and feed their young with a mixture of the 

 same, called bee-bread. Various kinds of bees are domesticated for the 

 sake of their stores of wax and honey, and are thus made to contribute 

 directly to the comfort and convenience of man, in return for the care 

 and attention afforded them. Honey and wax are also obtained from 

 several species of wild bees (Melipona, Trigona, and Tetragona), 

 essentially different from the domesticated kinds. While bees and other 

 hymenoplerous insects seek only the gratification of their own inclina- 

 tions, in their frequent visits to flowers, they carry on their bodies the 

 yellow dust or pollen from one blossom to another, and scatter it over 

 the parts prepared to receive and be fertilized by it, whereby they render 

 an important service to vegetation. 



7. — DiPTERA {Mosqiiitos, Gnats, Flies, Sfc). Insects with 

 a horny or fleshy proboscis, two wings only, and two knobbed 

 threads, called balancers or poisers, behind the wings. Trans- 

 formation complete. The larvee are maggots, without feet, 

 and with the breathing-holes generally in the hinder extremity 

 of the body. Pupae mostly incased in the dried skin of the 

 larvae, sometimes, however, naked, in which case the wings and 

 the legs are visible, and are found to be more or less free or 

 unconfined. 



The two-winged insects, though mostly of moderate or small size, are 

 not only very numerous in kinds or species, but also extremely abundant 

 in individuals of the same kind, often appearing in swarms of countless 

 multitudes. Flies are destined to live wholly on liquid food, and are 

 therefore provided with a proboscis, enclosing hard and sharp-pointed 

 darts, instead of jaws, and fitted for piercing and sucking, or ending 

 with soft and fleshy lips for lapping. In our own persons we suffer 

 much from the sharp suckers and blood-thirsty propensities of gnats and 

 mosquitos {Culicido'), and also from those of certain midges {Cerato- 

 pogon and Simulium), including the tormenting black-flies {Simulium 

 molesfum) of this country. The larvae of these insects live in stagnant 

 water, and subsist on minute aquatic animals. Horse-flies and the 

 golden-eyed forest-flies (Tabanidcp), whose larva? live in the ground, 

 and the stinging stable-flies {Sto7noxys), which closely resemble common 

 house-flies, and in the larva state live in dung, attack both man and 



