OF SMELL. 215 



or even less, from its death, an elephant will be covered with 

 myriads of black flies, not one of which had been visible 

 before. 



Not only can no odour whatever be detected by human 

 noses, but the sudden arrival of the flies is often the first 

 intimation to the bystanders that the animal is really dead ; 

 yet some extraordinarily subtle odour there must be, and it 

 must have travelled through the air with a speed which is 

 equally extraordinary. 



White sugar is to us utterly without smell, yet Sir J. 

 Emerson Tennent mentions that the smallest particle, 

 though wrapped in paper and placed in the centre of a 

 table, is quite enough to attract the small black ants, a line 

 of which will be formed in a few minutes to effect the re- 

 moval of the delicious morsel. 



Flies seem to be guided by scent and scent only ; for, 

 when she cannot get at the meat, the bluebottle, or blow-fly, 

 will lay her eggs on the wire-gauze meat-cover, and in this 

 case one would say she must be deceived by the smell, for 

 she can hardly know that, though it is beyond her own 

 reach, her eggs will fall through and her children thus find 

 their necessary food. It is, at all events, quite certain 

 that gauze is no sufficient protection against her and her 

 family. 



In tropical countries where the extreme heat and dryness 

 of the air combine to shrivel up any dead body so rapidly 

 that it can hardly be said to putrefy, and so completely 

 that travellers in the woodless pampas can make their fire 

 of a dead horse, carrion-beetles, though not absent, are not 

 numerous. On the other hand, they abound in damp tern- 



