130 



DIPTERA. 



slightest wetting. The process by which this is accomplished affords a very 

 interesting spectacle. The pupa having risen to the surface, elevates its 

 thorax above the water, the skin soon splits down the back and exposes the 



FIG, 132. LARVA OF GNAT. 



FIG. 133. ESCAPE OF GNAT FROM ITS PUPA-C 



fore-parts of the gnat, which are quickly protruded, and the gnat, floating on 

 its old skin as in a boat, extricates its wings from their cases and its legs from 

 their boots. The wings unfold themselves, and the little creature flies away 

 to enjoy its new existence in another element. 



FIG. 134. METAMORPHOSES OF PLUMED GNAT. 



The Crane-Plies (Tipula) constitute a very numerous race, some of 

 which are nearly related to the gnats, and pass the first period' of their exist- 

 ence in the water. In their larva state they resemble little red worms, having 



