96 NATURAL HISTORY OP 



season of the year by a rapid evaporation, and the 

 smaller streams at one time undergo the same tate, 

 and at another assume the character of torrents. 



As providence in the creation of insects seems 

 partly to have designed them for removing various 

 nuisances and superfluous materials from the face 

 of nature, their distribution is regulated accordingly, 

 and their numbers proportioned to the work assigned 

 to them. In temperate climates, for example, where 

 the dead carcasses of animals decompose but slowly, 

 our senses would be continually offended, and our 

 health liable to injury, from the unwholesome mias- 

 mata that exhales from them, unless some provision 

 were made to accelerate their removal. We ac- 

 cordingly find a profusion of carcass-eating beetles 

 Necrophori, Silphidce, &c which speedily as- 

 semble from all quarters, round a dead body, led by 

 the emanation of the tainted air, and in a short pe- 

 riod it is either buried or consumed. In several 

 extensive countries of South America, however, 

 where the extreme dryness of the air and heat of the 

 sun cause the animal juices to evaporate with such 

 rapidity that a dead body can scarcely be said to 

 putrefy, but is converted into a substance so com- 

 pletely desiccated, that travellers across the woodless 

 pampas sometimes make their fire of a dead horse, 

 such insects would scarcely be required, and ac- 

 cordingly few if any have been observed. In this 

 country, and others under similar latitudes, nature 

 has devolved the task of removing excrementitious 



