THE SCREW WORM FLY is somewhat larger than the common house fly, but resembles the latter in general appear ance. The color is a metallic green, with three black stripes on the back. The eggs of the screw worm fly are laid in wounds or natural openings of animals, or of man, and the grubs, after hatching, bore into the flesh, making deeper wounds. Infested animals, if untreated, may (lie of blood poisoning. Tar, grease or fish oil on wounds will sometimes as sist in keeping the flies away. If wounds become infested, it is necessary to re move the maggots and treat the surface with a solution of corrosive sublimate or crude carbolic acid.