mPTRRA. 83 



The genus Musca (fly), in which Linnaeus comprised the immense 

 eries of Diptera, with the exception of the Tipulida, the Tabanidce^ 

 he A si/ idee, the Bombylidcs, and the Empidce, is now reduced to the 

 louse Fly and a few resembHng it. The habits of these trouble- 

 ome companions are in conformity with the two great principles of 

 .nimal Hfe, that is, eating and propagating their species. 



Flies feed principally on fluids which exude from the bodies of 

 .nimals ; that is, sweat, saliva, and other secretions. They also seek 

 ege table juices ; and they may be seen in our houses to feed eagerly 

 m fruits and sweet substances. 



The common flies deposit their eggs on vegetables, and particu- 

 arly on fungi in a state of decomposition, on dung-heaps, cow dung, 

 5cc. They are essentially parasites, settHng on both man and beast, 

 o suck up the fluid substances which are diftused over the surface of 

 heir bodies. In our dwellings they eat anything that will serve to 



Fig. 61.— Lancet of the Meat Fly. Fig. 62, -House ¥\y {Musca domestica). 



nourish them. Generation succeeds generation with the greatest 

 apidity. 



The House Fly {Musca domestica, Fig. 62) is about three lines in 

 length, ash-coloured, with the face black, the sides of the head 

 yellow, and the forehead yellow with black stripes ; the thorax is 

 marked with black lines ; the abdomen is pale underneath, and a 

 transparent yellow at the sides, in the males, and is speckled with 

 black. The feet are black ; the wings transparent, and yellowish at 

 the base. This species is extremely plentiful throughout the whole 

 of Europe. Every one knows how annoying it is towards the end of 

 the summer, and especially so in the South of France during the hot 

 season. 



The Ox Fly {Musca bovina\ a near relation of the house fly, is 

 also very common. It setdes on the nostrils, the eyes, and the 

 wounds of animals. 



The Executioner Fly {Musca carnifex), which is not rare m 

 France, also attacks oxen. It is of a dark metallic green colour 



