134 



PLANTS AND ANIMALS 



rapid. A single fly lays 

 about one hundred and 

 twenty eggs on the aver- 

 age, in manure and decay- 

 ing material, which hatch 

 within a day, producing 

 maggots or larvae. The 

 larvae or maggots go into 

 the pupal or quiet stage 

 after a few days, from 

 which stage they come 

 forth as flies in less than a 

 week. The puparium is shown to the left of the illustra- 

 tion and the larva to the right. The other illustration 

 shows a blue-bottle fly, .also magnified five times. This fly 

 is also called the meat fly, and breeds in decaying animal 

 matter. All of these flies may carry disease. The com- 

 mon house fly should be called the typhoid fly as it is a 

 carrier of that disease. 



We should protect ourselves from the flies by 

 screens, and do what we can to deprive them of foods. 

 No decaying materials should be allowed anywhere in 

 the yard or neighborhood. Horse stables should have a 

 proper place for storing the horse manure until it can be 

 carried away. Absolute cleanliness is a great preven- 

 tive of flies. Sticky fly paper and fly traps will help to 

 remove the flies which come into the house. 



The diseases which are caused by bacteria are dif- 

 ferent from the poisons which the bacteria produce. The 

 ptomaines act quickly while the diseases take several 

 days, or perhaps weeks, in which to develop. The devel- 



Cut supplied through United States Department of Agriculture. 



