TYPICAL INSECTS 203 



short conical abdomen. It has six stout legs, with five- 

 jointed feet, which have a pair of pincer claws at the end and 

 a pair of pads underneath. 



These pads are beset with hairs, from which exudes a sticky 

 substance that enables a fly to walk upside down on the ceil- 

 ing. The gauzy wings are not folded over each other, but 



FIG. 65. House-fly. 



( Photomicrograph.) 



are laid flat against the back and reach beyond the body. 

 Examine a fly closely and you will find a pair of small, curved, 

 rod-like organs in the place where the second pair of wings 

 ought to be. In fact this is all that is left of the second 

 pair. They are called halteres and may serve to rest 

 the front wings upon while soaring. In some species of this 

 group the second pair of wings is represented by a pair of 



