114 N TES ON FOXES TR Y. 



version into charcoal, or otherwise utilising it, if 

 such intentions were entertained. Then should 

 follow proposals for reproduction, with the ex- 

 perience or data on which the method has been 

 accepted as reliable. 



On the system of rotation of area, with a fairly 

 just proportion of stock of all ages, and with 

 moderate uniformity of soil (reproduction being 

 ensured), it is easy to secure uniformity of yield 

 for all time ; but on the Planter betrieb, the expe- 

 rience of Germany has shown, not only that it 

 is difficult to maintain uniformity of yield, but 

 that there is commonly a temptation to secure 

 good financial results in the present, in the hope 

 that they may be maintained permanently, at least 

 for our own time ; and as it is difficult to determine 

 the amount of standing stock and average rate of 

 annual increment in a forest of trees of all ages, 

 this hope is not always well founded. We may 

 base our plan upon a fairly reliable estimate of 

 trees of the final period, and may have fair data 

 for assuming that there is an equal number of trees 

 in the penultimate period of growth to take their 

 place when they shall have been felled ; but unless 

 we are secure of a corresponding area of trees of 

 each younger period, we may in time have to 

 suspend operations, or lower the felling age by per- 

 haps twenty years, to the lasting impoverishment 



