18 



the number of years iu the rotation. In popular estimation 

 a forest consists of a confused collection of trees of all sizes. 

 This is not, however, the case in an organized forest capable 

 of furnishing an uninterrupted supply of material of a defi- 

 nite kind. Such a forest must be built up, so to speak, of 

 an unbroken series" of trees or of crops of all ages from the 

 seedling to the mature tree. Thus, were we dealing with 

 isolated trees, and were it desired to fell one 20-year old tree 

 every year, it- is evident that it would be necessary to have 

 already growing at least 20 trees, one tree 20 years old, one 

 of 19 years, one of 18 years, and so on down to the seedling 

 of one year. Had we not this stock of trees of different ages 

 to deal* with, the desired felliag could not be made. Were, 

 for instance, all the trees of the same age, say 10 years, we 

 should be obliged, in order to obtain one tree a year, to 

 commence by felling a tree 10 years old and should end by 

 felling a tree 30 years old. 



Similar reasoning applies to crops, that is to say to coUec- 

 tious of trees occupying definite areas. If it were desired to 

 fell every year one acre of forest containing trees 20 years old, 

 it would be necessary to possess 20 acres of forest, of which 

 one acre should be 20 years old, one 19 years, and so on down 

 to the crop one year old. In each case a growing stock of 

 20 trees or 20 acres is requisite in order that one tree, or one 

 acre of forest, may annually become available for felling 

 when aged 20 years. 



If we suppose that, as in iig. ITo, 1, the growths of the crops of diSerent age 

 are represented to scale on the vertical line, and the areas occupied hy each crop on 

 the horizontal line, the arrangement of the crops might be graphically represented as 

 there shown. It is evident that with a forest so constitutod, there could be felled 

 each year a crop 20 years old, one acre in extent, and that the felling might be repeated 

 year after year. There would always be on the ground, immediately before a felling 

 in a given year, a series of crops from 1 to 20 years old — in faot the same wood 

 capital, or growing stock. 



If instead of this regularity, some of the age-classes were missing — if, we will 

 suppose, there .were no crops of from 10 to 18 years of age — it is evident that, 2 years 

 after the commencement of operations, the oldest crop would he 12 years old, and it 

 would be necessary either to fell trees of that age or wait for 8 years until the oldest 

 crop was aged 20 years. In this case, which is graphically represented in 6g. 

 No. 2, the growing stock is insafflcient and is irregularly constituted, some of tfie 

 age-classes being absent while others are in excess. Such irregularity in the consti- 

 tution of the growing stock will very frequently be met with, and is, indeed, the rule 

 rather than the exception in Indian forests. 



3. Arrangement of age-classes when these are irregularly dis- 

 tributed.— We have assumed above that the crops of different 

 ages have been arranged in groups, following one another iu 

 regular succession, as is generally seen in the case of coppiced 

 forests. If, however, the growths of different ages were 



