368 INJURIOUS EFFECTS OF [PART II. 



the fertility it possesses from a vegetation which 

 has covered it from the beginning, has decayed 

 annually through ages, and has thus formed a layer 

 of vegetable mould, in most cases very thin. If 

 this vegetation he burnt down, the wind carries 

 away the light ashes another vegetation springs 

 up, but less vigorous than the first, until by re- 

 peated conflagrations the land becomes perfectly 

 exhausted. 



Large districts in New Zealand have in this 

 manner been rendered very poor. If the soil is 

 originally covered with a forest, the vegetation after 

 the first conflagration is a luxuriant underwood; 

 if this is burnt down in its turn, high fern and flax 

 spring up ; if the burning is repeated, the new flax 

 is much lower, the fern less vigorous ; they inter- 

 mix with the Leptospermum and Gaultheria, which 

 delight in a meagre clayey soil, until at last stunted 

 fern, rushes, club-mosses, and meagre shrubs of Lep- 

 tospermum are the only plants which the soil is 

 capable of producing; and many places are even 

 quite bare, and show the white clay, which re- 

 sembles pipe-clay. As the natives, from a know- 

 ledge of the nature of their plains, prefer, with few 

 exceptions, the scattered ravines and hills for their 

 plantations, they are continually lighting fires in 

 order to clear a road when they are travelling, and 

 these have not failed to produce their natural effect. 

 In New South Wales I observed this destructive 

 influence to a still greater degree. When travelling 



