THE PLY. 75 



dead insect. Accurate microscopic observations were 

 made upon it by Nees v. Esenbeck in 1827, though 

 he did not arrive at any very definite conclusions as 

 to the nature of what he observed. But in 1835 

 Mons. Dumeril declared the fine white dust to be 

 a true mould, which had probably caused the death of 

 the animal, in the same way that plants are killed by 

 the difi'erent species of Exysiphe : he compares it to 

 the ' muscardine ' of the silkworm." 



With this extract we shall close the life-history of 

 the Fly, and shall now consider for a moment the 

 uses for which it was created, and the lessons we may 

 learn from its existence. 



If you asked a sceptic, who doubted that every 

 species of animal is created for an end, and has its 

 place and object assigned by the Creator, to name 

 some of those that he regarded as useless, it is not at 

 all improbable that he would select the Worm and 

 the Ply. Of the Worm's value as a fertilizing agent 

 we have already spoken (Letter III.), and shall now 

 find that the humble Fly, in its lowest stage, per- 

 forms an ofl&ce of still greater importance, — nay, 

 that it is indispensable to the existence of some, and 

 to the health and comfort of the whole human race. 

 Reader ! this is no exaggeration : go into the fields 

 or lanes, and seek the body of some recently-killed 

 animal; or, if you reside near the sea, look at the 

 carcase of one of the many creatures that are cast up 

 by the waves; and if your olfactory organs be not 

 too easily offended, turn the body over, and examine 



£ 2 



