THE " QUICK- WINGED GNAT" 53 



You may think it sounds strange to say 

 the little creatures hang themselves from the 

 water, but this is really exactly what they do. 

 Although they are so small the baby Gnats 

 are heavier than the water, and would sink to 

 the bottom of the pond if they could not 

 fasten themselves to the top in some way. 

 But one branch of the forked tail, with which 

 each little larva is provided, is really a breath- 

 ing tube ending in five tiny flaps. These flaps 

 can be closed, making a pointed tip to the 

 tube, or opened so that they spread out and 

 form a tiny cup. 



When the great gnat comes up to the top 

 of the water, it pushes the pointed tip of its 

 breathing tube through the surface-film and 

 opens the little cup, which at once becomes 

 filled with air, and rests lightly on the surface 

 like a buoy, and supports the little creature 

 as it hangs head downwards in the water. 

 When it dives below the larva closes the flaps, 

 shutting in a bubble of air which it uses for 

 breathing while it stays beneath the surface. 



The baby Gnats grow very fast, and if all 

 goes well, and there is plenty of food for them 

 in the pond, in about ten days' time they are 

 full grown. One might well wonder what 



