DISAPPEARANCE OF FORESTS. 31 



In the second case the evil may have been done by the 

 weight of a load of snow resting on it in winter, or by the 

 growth upon it of some parisitic fungus. In the third 

 case the damage may have been done by a thunderstroke, 

 or through the leaves having become infested with a 

 destructive insect; in the next case the decay of the 

 trunk may be attributable to a twig having been broken 

 by some bird or beast ; while in the last mentioned case 

 all may have been the consequence of a gale. Such 

 accidents are of frequent occurence. 



But all the destruction caused or occasioned thus is 

 as nothing compared with the destruction which has been 

 occasioned by man. In the organic structure of man, 

 and in many other organisms besides, there may be seen 

 at times a remedial operation going on ascribed to what 

 in default of fuller knowledge has been called the vis 

 mediatrix ; so do we find in operation in primeval forests a 

 remedial process whereby trees thus destroyed are re- 

 placed by others — it may be their superiors in the vege- 

 table scale ; but the destruction effected by man has been 

 carried on so extensively as to render in general this 

 provision unavailing or insufiScient to repair his devastating 

 work. Sometimes this destruction by him has been wrought 

 with a purpose ; sometimes it has been wrought only in 

 recklessness of consequences ; sometimes his only purpose 

 may have been to obtain a beam or a switch ; sometimes 

 it may have been done to clear the ground for agriculture ; 

 sometimes through his sending his flocks or herds into the 

 forest for pasture without any thought of damage ; some- 

 times through his kindling a fire wherewith to cook his 

 jjrovisions, and neglecting to extinguish it on leaving; 

 sometimes through his throwing down a burning match 

 after lighting his pipe ; sometimes through his burning the 

 bushes, or grass, or herbage, outside the wood to clear the 

 ground for the plough, or with a view to securing a new 

 succulent crop for his herds, and not keeping fire under 

 control, and the extensive destruction of forests was the 

 consequence. 



