CHAPTER VI 



IN the preceding chapters we have become acquainted 

 with the life habits of the House Fly and its natural ene- 

 mies which, before the advent of that insanitary creature, 

 Man, were able to satisfactorily maintain the balance of 

 Nature. The House Fly is one of Nature's sanitary service, 

 and in the past its mission in life was to help to keep the 

 atmosphere free of noxious gases which are so prejudicial 

 to the health of all animal life. So acute is the sense of 

 smell in the House Fly that should an animal perish, the 

 effluvia given forth by its carcase attracts the flies for a 

 mile and more around. Swarming over the carcase they 

 deposit their eggs in the nostrils, eyes, ears, and other 

 suitable situations. In a few hours these eggs hatch into 

 maggots which immediately begin to devour the decaying 

 animal. During the terrible cattle plague known as the 

 Rinderpest which swept through South Africa some years 

 ago, I saw on one occasion some hundreds of carcases of 

 cattle which were literally moving, undulating masses of 

 maggots. Visiting the spot after the lapse of a couple of 

 days, I found the maggots had devoured every ounce of 

 flesh, leaving only the skin and bones. The maggots had 

 changed meantime into chrysalides, preparatory to emerging 

 as fully developed flies. Within the hides of what were 

 once cattle, I saw countless millions of these chrysalides. 

 On another occasion I came across the body of a large 



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