182 THE DANGER OF FLIES 



fly laying. Creolin, in its cheap commercial form, is 

 also recommended, sprayed over the manure-heaps 

 every two or three days. It not only deters flies from 

 ovipositing, but should they succeed in doing so it 

 kills the resulting larvae.* 



Ross has shown us how to clear Ismailia of malaria ; 

 the Americans have rid Havana, for the first time in a 

 century, of yellow fever ; the same could be done with 

 flies, if only the people liked to have it so. The motor- 

 car, with all its destruction of nervous tissue, its pre- 

 vention of sleep, its danger to life and to limb, has one 

 great merit it affords no nidus for flies. 



* Theobald, ' Second Report on Economic Entomology,' 

 British Museum (Natural History), London, 1904, p. 125. 



