109 



The general working scheme would be framed and the circles- 

 and periodic blocks or coupes corresponding to this frnme- 

 work would be laid out. Until this is done, and ihe place 

 which each portion of tl.e forest will occupy in the final 

 scheme is known, tlie cultural rules to be a|iplied to each crop 

 cannot be prescribed. Tbe general working scheme gives the 

 order in which tlie various portions of the working-o'rcle are 

 to be taken up for transformation during each successive 

 period. The formation of the working-circles is not a matter 

 of difficulty. A correct gradation of ages is by hypothesis 

 unobtainable. The duration of the provisional plan for the 

 transformation of the forest would be equal to the exploit- 

 able age of the forest which it is sought to constitute, and 

 would be determined in the same way, that is to sny^ it 

 Tfould depend on the size of the expli)itab!e trees and on th& 

 rates of growth. Tlie periodic blocks would consist of a few 

 great natural divis-ions of the forest, chosen so as to furnish 

 more or less equal material during corresponding sub-mul- 

 tiple periods of the exploitable age. Indeed, the general 

 scheme is usually very obvious and well defined. TV hen it 

 has been thus drawn up, two clasfes of operations will be- 

 required, namely, (1) transformation fellings in those por- 

 tions of the forest which are to be first regenerated, and 

 (2) modified selection fellings elsewhere. 



The transformation fellings do not usually differ very 

 materially, at least in principle, from ordinary successive 

 regeneration fellings; but their execution will dtpend more- 

 markedly on the nature of tlie crop, and it will be necessary 

 to change the manner of applying them from place to plrce 

 according to the irregularities met with. Where reproduc- 

 tion is abundant, they will simply remove the mature trees 

 in Mhatever way is required, so as to leave room for the 

 young growth to develop. Where there is little or no young 

 growth already established, it will be sought to obtain 

 reproduction in the ordinary way by successive fellings,. 

 preparatory or seed, secondary and final. The selection 

 fellings to be carried out in the blccks to be regenerated 

 later on off"er no diflficulty. Tbe trees to be removed will be- 

 such as cannot maintain themselves in a soui d state until 

 the crop in v^ hich tht y grow reaches its turn for regeneration ^ 

 Knowing the length of the rotation and the rates of growth, 

 the question is easily determinable. Thus, where the 

 exploitable size of the trees is 24 inches in diameter, witk 

 a rotation of 120 years, and a rate of growth of 10 years for 



