242 CHEESE-MITES AN>D FLIES. 



black ; it is very inconspicuous, and we should 

 hardly suspect its object in visiting our cheese. 

 When cheeses are made and placed in a room 

 to dry, before the outside rind has had time to 

 harden, the Piophila will seek out some crevice 

 in which to deposit its eggs. The creature is 

 furnished with an ovipositor, which it can thrust 

 out to a great length so as to penetrate to a con- 

 siderable depth into the cracks of the cheese, and 

 there it will lay as many as two hundred and fifty 

 eggs. These hatch into white grubs without feet, 

 but having two horny claw-shaped mandibles which 

 enable them to bore into the cheese upon which 

 they feed. 



The breathing apparatus of the cheese-maggot is 

 very remarkable, consisting of two tubes at the head 

 and two at the tail, so the grub can breathe at 

 either end of its body. Lest any particles of cheese 

 should obstruct the front pair of tubes the little 

 creature has the power of drawing over them 

 a fold of the skin, and whilst they are thus 

 closed it breathes through the air-tubes in the tail. 

 A cheese inhabited by these grubs soon grows 

 moist and rotten, because they have the power of 



