118 Objects for the Microscope. 



CHAPTER IV. 



DIPTERA. 



happy living things ! no tongue 



Your beauty may declare ; 

 A spring of love gushed from my heart, 



And I blessed you unaware." 



Ancient Mariner. 



OF all the insect tribes in that world which lies about us, 

 and of which we know so little, with all our learning and 

 research, there is none which has been more neglected than 

 the numerous and interesting one of the Diptera, or two- 

 winged flies. Most strange that it should be so ; for they 

 are the least harmful and the most truly beneficial to man of 

 any small creatures ; few of them assault us, and as a body 

 they are so important that the world could almost as easily 

 do without flowers or sunlight as without Flies ! 



They are beautiful. Who has not unconsciously paused 

 to admire the metallic lustre of an unknown Beris or Doli- 

 chopus, as it rested on the laurel-leaf by his side ; or the 

 golden Leptis sitting on the gray bark of some old tree ; 

 or the variegated Syrphus and the pretty Empis thronging 

 the umbelliferous plants by the wayside ? Who has not, 

 in the listless heat of a summer's day, watched the merry 

 dance of the little House-fly, and wondered if there was 

 not more intelligence in that world of flies than he had 

 dreamed of? They are useful; for the Diptera in their 

 larval state feed upon the dung of animals and decaying 

 substances, and we should perish from the noxious vapours 

 or gases which arise from dead matter without these little 

 scavengers. 



We are indeed in a world visible yet unknown, the 

 perfection and order of which no human eye had ever seen 

 without this help from God, whose directing providence 



