THE DESTRUCTION OF THE FOREST. 87 



floating ice, which, becoming gorged in shallow places in the 

 stream, back up the waters above. The increased frequency 

 of inundations in the United States is, to a great extent, to be 

 attributed to the rapid destruction of the forests." 



Sir Charles Lyell, in his "Principles of Ge- 

 ology," * speaking of the effects produced by the 

 removal of the forest, says, on page 457 : 



" When St. Helena was discovered, about the year 1506, it 

 was entirely covered with forests, the trees drooping over the 

 tremendous precipices that overhang the sea. Now, says Dr. 

 Hooker, all is changed ; fully five-sixths of the island is en- 

 tirely barren, and by far the greater part of the vegetation 

 that exists, whether herbs, shrubs, or trees, consists of intro- 

 duced European, American, African, and Australian plants, 

 which propagated themselves with such rapidity that the na- 

 tive plants could not compete with them. These exotic species, 

 together with the goats, which, being carried to the island, de- 

 stroyed the forests by devouring all the young plants, are sup- 

 posed to have utterly annihilated about one hundred peculiar 

 and indigenous species, all record of which is lost to science, 

 except those of which specimens were collected by the late 

 Dr. Burchell, and are now in the herbarium of Kew." 



The protective action or plants generally as pre- 

 venting erosion by water or wind is clearly pointed 



*" Principles of Geology," by Sir Charles Lyell, M.A. 

 London : John Murray, 1872. Pp. 652. 



