Fie. 7. On the fourteenth day the pupa bursts its skin at 

 the surface of the water, and the perfect gnat begins to 

 emerge, 



FIG. 8. and slowly rises into the air, which is henceforth 

 its proper element, 



FIG. 9. finally withdrawing its legs and wings from the 

 last encumbering folds of the pupa skin. 



FIG. 10. Two minutes later it is trimming its wing 

 in readiness for flight. 



Photo: James's Press Agency. 



HOUSE-FLY (Musca domesticd] 



It is bred in rubbish heaps during the summer months. The House-Fly is an agent 

 in carrying typhoid germs, which readily adhere to the numerous hairs seen on the fly's 

 body and appendages. (The Blow-fly, or Blue-bottle, lays its eggs on dead animals, 

 and on joints in the larder if it has access to them.) 



