88 OUR INSECT FRIENDS AND FOES 



and adapted for piercing the skin and sucking up 

 blood; while those specimens with the plume- 

 like antennae have comparatively simple mouth- 

 parts. These modifications of the antennae and 

 mouth-parts are the distinguishing features of 

 the two sexes; the specimens with simple 

 antennae but complex mouth-parts are the 

 females, and those with plume-like antennae but 

 less complex mouth-parts are the males. The 

 females, with their piercing lancet and tubular 

 proboscis, are most blood-thirsty insects, and it 

 is from this sanguinary habit that the females of 

 certain species have become transmitting agents 

 of disease. 



The female Gnat (Culex) lays her eggs upon 

 the surface of stagnant pools in curious boat- 

 shaped masses, each tiny mass numbering some 

 250 to 300 eggs glued together with a sticky 

 secretion. Each egg is pointed at the upper 

 end, and is provided at the lower end with a lid, 

 through which the larva ultimately makes its 

 escape into the water. The Gnat larva on 

 emerging from the egg, is a curious looking little 

 creature, with a large head, a long slender body, 

 and what at first glance looks like a forked or 

 double tail. The body is destitute of limbs, but 

 the front of the head is provided with vibratile 

 bristles, which are used for sweeping into the 

 mouth the particles of organic matter upon 

 which the larva feeds. From the eighth 

 abdominal segment is developed a curious 

 cylindrical respiratory syphon through which 

 the larva draws in its supply of air, and which is 

 traversed by a pair of large air-tubes continued 



