INSECTS 55 



The female gnat, when laying her eggs, stands on a con- 

 venient leaf or stick, and carefully builds an egg raft, by 

 means of her hind legs. This little craft, wliich is composed 

 of 100 to 300 eggs, is so perfectly arranged that it defies the 

 elements, and remains upright even when the miniature pond 

 becomes a storm-driven ocean. Each egg is cigar-shaped, the 

 submerged end being capped. When the eggs hatch the cap 

 or lid opens, and the young gnat, a most original little 

 creature, drops into the water beneath. The larva spends its 

 life feeding, washing into an ever waiting mouth, by means of 

 a small brush, small creatures or organic matter. Nature has 

 kindly arranged that the breathing tubes should be at one 

 end of the larva, and the mouth at the other, and so it is 

 able to breathe at the surface, and feed beneath the water at 

 one and the same time. 



The gnat larva is dependent on atmospheric air, and there- 

 fore is not perfectly adapted to aquatic conditions, few if any 

 of the water-flies are, for it would seem that in some bygone 

 days the flies with aquatic larva of to-day found life in the 

 air not over pleasant, and hence preferred aquatic to aerial 

 conditions. The larva of the gnat, being heavier than the 

 water it displaces, relies on the water film to hold it whilst 

 obtaining air from the atmosphere. Several moults are 

 undergone during the three or four months before the larva 

 turns into a pupa. For several days the pupa swims by 

 means of a peculiar jerking motion, and although unable to 

 feed is sensitive to its surroundings, and exhibits clear 

 visionary powers. The pupa case splits, and the Imago, draw- 

 ing itself out, stands on the empty skin, which is utilised as 

 a raft, and after stretching its wings flies away, either to join 

 the dance or to lay eggs, and possibly torment some unfortu- 

 nate biped. 



Many a Corethra, innocent though it be, falls a victim to 

 the hands of man, on account of the striking resemblance it 

 bears to the much-hated mosquito. It is only during the 

 larva stage that the two insects are in any way alike. The 

 young corethra is known as the phantom larva, a name little 

 to be wondered at, for no sooner is a specimen noticed than it 

 as mysteriously vanishes, only to re-appear the very next 

 moment, possibly half an inch from its previous position for 

 some moments the larva rests contented and motionless near 

 the surface, until suddenly with lightning velocity it changes 

 its direction and faces the other way. It is a long narrow 

 creature of extraordinary transparency, resembling clear glass ; 

 in fact hundreds of these creatures may be in the pond under 



