1 ACTS ABOUT WKLL KNOWN ANIMALS. ".»< 



tour-liuiulri'dtlis of an inch loni;, one-fourth as wide, (hill 

 white in i-olor, and pitted with elongate, hexagonal dcpres- 

 sjions — mere whitish sspees to the unaided eye, laid in little 

 agglutinated i)ilcs in warm manure or in deeom[>osmg vege- 

 tation, especially tliat about our stables and barn-yards. 

 From SO to 100 are laid at a time, and probably at three or 

 four dill'erent intervals by the same fly, though on this point 

 we have no I'xai-t data. Within 24 bonis, in summer, they 

 hatch into footless maggots, which, after rioting in filth till 

 their tender skins seem ready to burst from repletion be- 

 come full-fed in less than a week and, descending into the 

 earth or sheltering under some old board, contract to brown, 

 shining objects, rounded at both ends, and technically 

 known as puparia. Within the darkness of this hardened 

 skin piofoiin<l changes rapidly take place, and the insect 

 passes through the pupa to the perfect state, and finally, in 

 about five days, liie anterior end of the puparium is j)U.shed 

 oil and the fly quickly crawls out. At first its parts are 

 pale and soft, and its wings arc crum[)led and useless, but 

 these soon expand, and suddenly, without practice or teach- 

 ing the new-fledged fly wings its way to your table to mock 

 your displeasure — to share your rejiast. The length of time 

 required from hatching to maturity varies with the season 

 and temperature, but will not exceed ten days in midsum- 

 mer, while the life of the perfect fly lasts about three weeks 

 at the same .season. As cold weather approaches j>ropaga- 

 tion ceases, and the older flies perish. A few of ihe more 

 vigorous females, however, retreat to some nook or cranny 

 where, in a state of torpor, they survive till the ensuing 

 sea.son — links 'twixt the summer gone by and to come. The 

 in.sect may also hibernate in the pupa state in the ground, 

 as I have fouinl the jmparia quite late in the fall. In 

 rooms kept continuous!}- warm, or in more .southern lati- 

 tudes, the fly remains active all winter, and our palace 

 sleeping-cars bring them daily to us from Florida during 

 the coldest months of the year. 



I have no figures of the house-fly in its difierent states 



