HABITS OF DRAGON FLIES. 81 



flitting; around the sides of buildings and hay ricks, or 

 skirting the borders of a piece of woods at or sliortly after 

 sunset. All dragon flies are distinctively diurnal, how- 

 ever, and night finds them totally inactive. The summer 

 sun is their god ; when he shines every element in their 

 being is alive as if in homage to him, when his light and 

 heat are obscured by clouds or diminished by chilling 

 winds their worship ends. They are short lived and fre- 

 quently destroyed in large numbers by heavy showers and 

 winds through their inability to properly shelter them- 

 selves from the weather. After a severe storm their num- 

 bers are greatly diminished for several days, until renewed 

 l)y fresh emergings. Dragon flies with a few exceptions 

 (see table) confine themselves to the vicinity of their place 

 of birth, and even if removed therefrom quickly return. 

 They require in pairing and feeding, ample space and 

 great freedom. The dragon fly does not consider man and 

 his convenience in satiating its appetite, but destroys every 

 soft bodied insect which is unfortunate enough to fall in 

 its way, and the destruction of flies and mosquitoes is 

 merely incidental. I have seen Anax Junius chasing and 

 even capturing small butterflies which happened to ascend 

 to its elevation while hovering over a clover field. 



FLIES. 



I. Natural Conditions under avhich House Flies 

 Breed, with Life History so par as is Appli- 

 cable. 



The number of living North American species of Dip- 

 tera is estimated to be about ten thousand, with an equal 

 number in Europe. Only about one-fifth of these num- 

 bers comprise the family Muscidae, some of the members 



