DIPTERA 



155 



sprinkled with lime when emptied. Chicken pens should be cleaned often 

 and sprinkled with lime. 



The many little projections on the feet of the fly are tubular, and secrete 

 a sticky fluid which enables it to walk upside down. 



The blow-fly and the flesh-fly, close relatives of the house-fly, lay their 

 eggs upon meat, cheese, and other provisions or upon decaying animal sub- 



Fig. 125. — An adult mosquito, much enlarged, with all the parts that are 

 used in classification named. (Smith, N. J. Experiment Station, Bulletin 

 171, 1904.) 



stance, on which the maggots feed. Thus, while a great annoyance, they 

 may do some good by acting as scavengers. The most common flesh-fly 

 is perhaps Sarcoph'aga sarrace'nicB, which resembles a large house-fly. It 

 furnishes another example of viviparous insects; in other words, the larvae 

 are brought forth alive. 



