Forest Finance and Management 141 



not so strong as that cut from older trees, and con- 

 sequently does not bring so high a price. Again, 

 when a tree gets too old it is apt to rot at the 

 centre, thereby diminishing the quantity of sound 

 lumber it will furnish, even though it may still form 

 a new layer of wood every year. Another factor is 

 the different rate of growth of trees at different 

 ages. Take the white pine and its cousins, for in- 

 stance. The first three or four years the little 

 seedling grows but very slowly, except as far as its 

 root-system is concerned. Then comes a period, 

 which may last from thirty to fifty years, when its 

 growth is very rapid. If the young pines stand 

 close together, as they ought to if good lum- 

 ber is expected from them, this growth is especially 

 rapid in an upward direction. After that period, 

 they ought to be made to grow principally in diam- 

 eter, and that is done by cutting out a certain num- 

 ber of the trees, so that the rest may have a chance 

 to spread their crowns. As soon as they have done 

 this and formed a full, leafy top, they devote them- 

 selves to increasing their diameter, without, however, 

 ceasing to grow in height. This diameter growth 

 may continue for an almost indefinite time. Pines 

 have been known, that were over three hundred years 

 old, as shown by their annual rings, and still formed 

 new wood in their boles up to the time of their 

 felling. The amount of wood so formed every year 

 begins to decrease after a certain time, and in very old 

 trees is apt to be inconsiderable. The rate at which 

 the increase of wood takes place, at the different 



