70 



MOSQUITOES 



a long tube nearly as thick as the body itself, and it is 

 this tube which is extruded from the surface of the. water 

 every time the larva rises to breathe. The object of this 

 extrusion is to get air, and this tube is the breathing tube 

 of the insect. Its extremity is furnished with a breathing 



Fig. 8. — Mouth-parts of Larva of Cule.v pungens ; greatl}" enlarged. 

 (Author's illustration.) 



hole, or spiracle, and into it run two main trachejie, or 

 breathing tubes, which extend through the body of the 

 insect, giving off branches here and there, and thus carry- 

 ing air to all of its tissues. The true end of the body is 

 furnished with four flat flaps, the exact purpose of which 



