98 ANIMALS OF NO IMPORTANCE. 



These underwent similar contortions, so the bewildered fly 

 flew about seeking in vain a piece of terra firma^ whereon 

 he might rest the soles of his feet, The question was who 

 would tire first, the fly or myself. The victory fell to me, 

 and it was gained far more rapidly than I had expected. 

 In less than three minutes the fly was utterly exhausted. I 

 caught him, crushed him, and cast him forth. 



Not only are flies absolutely useless, but they are 

 positively injurious. They are the carriers of disease the 

 spread of enteric fever is another sin which is now laid to 

 their charge. I often wonder they are not systematically 

 caught and used as manure. Why does not the Agricul- 

 tural Department take up the matter, and thus at the same 

 time lessen disease and render the soil more fertile ? 



The fly lays its eggs in the filthiest of places ; a manure 

 heap is in its opinion an eminently desirable site. The 

 egg hatches out as a maggot a creature, to say the least 

 of it, not attractive. It possesses neither eyes nor feet ; it 

 does not need them since it is born and lives in the midst of 

 its food. After a time the maggot enters into the pupal 

 state. Its skin hardens just as that of a caterpillar does. 

 Inside the hardened integument the maggot literally melts; 

 and from the semi-liquid mass the tissues of the fly are 

 formed. The insect then emerges from his case to lead his 

 iniquitous life. Besides man, with his fly-flapper, flies 

 have many enemies. Lizards, spiders, frogs, toads, and 

 a host of other animals eagerly devour them. Most insidi- 

 ous of all are its plant foes. Two little fungi, termed 

 Empusa and Entomophthora, are parasitic on flies. Most 

 of us have seen dead flies stuck on to a window pane with a 

 kind of halo round them. These are flies which have been 

 destroyed by one or other of these vegetable moulds. An 

 infinitesimal spore is taken into the body of the fly and from 

 that moment the insect is doomed. The spore grows rapid- 

 ly and divides into a number of cells, until it has become 

 a much-branched tube which ramifies throughout the body 

 of the fly, absorbing its tissues. The growth of this para- 



