268 Mr J. W. Dawson on the Destruction and 



second growth may be already in the soil. It has been already 

 stated, that deeply buried tubers sometimes escape the effects 

 of fire, and, in the same manner, seeds imbedded in the 

 vegetable mould, or buried in cradle hills, may retain their 

 vitality, and being supplied by the ashes which cover the 

 ground, with alkaline solutions well-fitted to promote their 

 vegetation, may spring up before a supply of seed could be 

 furnished from any extraneous source. It is even probable 

 that many of the old forests may already have passed through 

 a rotation similar to that above detailed, and that the seeds 

 deposited by former preparatory growths may retain their 

 vitality, and be called into life by the favourable conditions 

 existing after a fire. This is a point, however, requiring for 

 its establishment a series of experiments which I have not 

 yet been able to undertake. 



If, as already suggested, forest fires, in the uncultivated 

 state of the country, be a provision for removing old and de- 

 caying forests, then such changes as those above detailed, 

 must have an important use in the economy of nature, since 

 by their means difi'erent portions of the country would succeed 

 each other in assuming the state of " barrens," producing 

 abundance of herbs and wild fruits suitable for the sustenance 

 of animals which could not subsist in the old forests ; and 

 these gradually becoming wooded, would keep up a succes- 

 sion of young and vigorous forests. 



Thirdly^ The process of restoration may be interrupted by 

 successive fires. These are most likely to occur soon after 

 the first burning, but may happen at any subsequent stage. 

 The resources of nature are not, however, easily exhausted. 

 When fires pass through young woods, some trees always 

 escape ; and so long as any vegetable soil remains, young 

 plants continue to spring up, though not so plentifully as at 

 first. Repeated fires, however, greatly impoverish the soil, 

 since the most valuable part of the ashes is readily removed 

 by rains, and the vegetable mould is entirely consumed. In 

 this case, if the ground be not of great natural fertility, it 

 becomes incapable of supporting a vigorous crop of young 

 tfees. It is then permanently occupied by shrubs and her- 

 baceous plants ; at least these remain in exclusive possession 



