26 North American Forests and Forestry 



the forest. The prostrate trunk for a number of 

 years encumbers the ground, but it has torn a wide 

 breach into the leafy canopy on top, through which 

 the bright sunlight enters the shady depth of the 

 wood. Gradually the fallen tree decays, helped in 

 this process by manifold fungi and other crypto- 

 gamic plants. After a while all that remains of 

 what was once a tree is a heap of rich brown vege- 

 table mould. As yet this is no place for a tree. 

 Only mosses, ferns, and a few flowering plants 

 which like to feed on organic matter and are known 

 to science as saprophytes, or decay plants, find a 

 congenial home here. But gradually, by various 

 processes, among which the burrowing of animals 

 plays no small part, the vegetable mould is mixed 

 with the underlying earth, and true soil formed. 

 Now is the time for the tree seeds, but if they do 

 not hasten to occupy the spot, a host of other plants, 

 herbs, grasses, and shrubs are lying in wait to get 

 themselves established and preempt the ground. 

 Of course, during the whole time while only fungi, 

 mosses, ferns, and other specially adapted plants 

 could live in the decaying mass, seeds of other 

 species continued to arrive on the spot, but found 

 it impossible to germinate. But now this has be- 

 come possible for them, and intense rivalry between 

 them follows. In this, if luck is with it, a young tree 

 may come off victorious and in course of time de- 

 velop into another giant like the fallen one on 

 whose grave it grows. 



This is but one instance where an accident 



