886 



THE NATURE BOOK 



-^-^^ 



THE CLEG, OR STOUT (H.SMAWPOTA). 

 (Magnified two diameters.) 



the reconstruction of the Hving debris, 

 is fonned the njmiph or pupa which, six 

 or seven days after the passing of the 

 maggot, emerges as Miisca domestica. 



Thus within three weeks during the 

 waiTuer months of the year any one Fly 

 female may give rise to no fewer than 

 one hundred or one hundred and fifty 

 individuals, for such is her egg-laying 

 capacity. 



A feature of the Fly is its face — merel}^ 

 a depressed vertical strip between the 

 two great eyes 

 which are close 

 together, and 

 which, being wide 

 in extent, enable 

 the Fly without 

 moving to see in 

 front, below, and 

 above, somewhat 

 sideways, also 

 fairly well round a 

 corner. Shght mag- 

 nification shows 

 the numerous 

 facets forming the 

 eye surface ; but 

 with the aid of 

 the microscope it 

 is found that each 

 one is the outer 

 portion of an 

 underlying lens, 

 and the astonish- 

 ing discovery is 

 thus made that 

 what at first sight 

 seemed a large 

 single eye is ac- 

 tually a combina- 



TKUNK OK I'KOBOSCIS 

 (Magnified.) 



tion of four thousand or more massed 

 together to function as one. 



^^^atch a House Fly settle an3Avhere, 

 and it will presently begin dabbing with 

 its long cushion-tipped trunk, selecting 

 tasty motes in\dsible to the human eye, 

 and quite hkely, at the same time, inno- 

 cently transferring equally invisible but 

 highly noxious genns casualh' carried 

 from some recent place of call. The lips, 

 tongue, and other mouth-parts have all 

 been utihsed to form this useful instru- 

 ment by means of 

 which the Fly 

 takes, or rather 

 siphons, up its 

 food, and with 

 which it can ex- 

 plore A\here it 

 could not possibly 

 put its head. 



For long it was 

 a mystery how 

 the Fly, " turning 

 gravity to jest," 

 walks and runs so 

 easily along a ceil- 

 ing, or up and 

 down a perpen- 

 dicular piece of 

 glass. The two 

 pyrifoiTn pads be- 

 neath the terminal 

 claws of each foot 

 were supposed to 

 act like suckers 

 when applied to 

 ])olished surfaces ; 

 but a closer in- 

 spection of the 

 pads revealed the 



