178 ZOOLOGY. 



The Cheese Fly (PiopMla casei), 

 one-fifth of an inch long, slender, with a metallic 

 sheen, almost hairless, black, with dirty yeUow legs 

 and wings of glassy clearness. These small flies 

 abound in front of the windows of places where 

 cheese is stored ; in summer and autumn the shining 

 white maggots, which are cylindrical in form with 

 tapering ends, and one-third of an inch long, live 

 in large numbers in old cheese, gnawing it through 

 and through, and making it dirty. Now and then 

 they spring forwards by bending their bodies into 

 a circle and suddenly straightening them again. 

 They become pupse on the walls or in straw, near 

 the cheeses from which they have crept out. 

 Remedies : Keeping the cheeses clean ; mechanical 

 exclusion (gauze screens outside the windows, en- 

 closure in chests). 



The Green-eyed Flies (GhZorops) 



include a number of small flies, under one-sixth of an 

 inch long, with spherical head, rounded greenish eyes, 

 strongly arched thorax, and short egg-shaped abdomen, 

 pointed in the male and blunt in the female. The 

 headless larvae live in the haulms of grasses and species 

 of grain; the life-history of a few forms only is 

 adequately known. A few are harmful, especially 

 as there are two or three generations annually. 

 The late summer generation often appears in large 

 numbers, indeed in actual swarms. Since no species 

 lives exclusively on corn, it is impossible to keep 

 them down for a long period of time. I describe 

 only two species : — 



The Eibbon-footed Corn Fly or Yellow Haulm Fly 



{Chlorops tceniopus), 



nearly one-sixth of an inch long, shining yellow ; the 

 antennae are black, and there are three longitudinal 



