NATURAL HISTORY. 135 



So she him lefte, and did her^elfe betake 



Unto her boat attain, with which she clefte 



The slouthful wave of that great griesy lake." SPENSER. 



upon it suspended in the same element ; and they cannot be 

 placed above the leaves, because the latter afford no footing for an 

 animal in size adequate to the consumption it is necessary to accom- 

 plish : they are, therefore, suspended beneath the foliage, and in 

 this manner they are brought in closer connection with the 

 branches, which alone could afford them support. 



414. In what respect are the habits of the sloth, as well as 

 being adapted to its own wants, in accordance with those of 

 external nature ? 



The sloth inhabits the deep, extensive, and luxuriant forests 

 of South America, in which the trees are of giant growth, always 

 green, and so close that rarely a beam of the vertical sun 

 reaches the earth ; they extend over districts so wide, and so 

 festooned and interlaced with twining plants, that winds, which 

 would level a single tree to the ground, barely agitate their 

 tops, or disfigure a few on the sides of the openings. 



In order that there may be seeds, and successions of races in 

 those luxuriant forests, it is necessary that there should be 

 consumers of the superabundant foliage, which otherwise would 

 completely exclude the sun and air, and the forest would perish 

 of excess of its ovvn exuberance, leaving the naked and carpetless 

 earth to be converted, by the fervour of the tropical sun, into 

 an arid waste, upon which no living thing could exist. 



If the forests were to be destroyed in this manner, or, indeed, 

 in any way but one in which their place should be occupied by a 

 close surface of vegetation, the rain would depart also, and the 

 land would be put beyond the power of human skill and labour 

 to bring it back to usefulness, either for himself, or for any other 

 living creature. " Once a desert, always a desert " untie one of 

 those mightier movements of nature, of which the records are 

 written in the strata of the deepest mines and the loftiest 

 mountains, break the rain to pieces, and mould and temper it3 

 elements anew.* 



Partingtou's " Cyclopaedia." 



