59 



from the youDgest to the oldest. This information can be obtained 

 only with the help of yield tables. 



Whether a given crop is exploitable or not must be determined 

 by the fact whether the percentage of increase demanded is beinw 

 produced by the crop. This can be settled only by investigations 

 in the crop itself. 



4. General remarii on the eminf of derelopmeut of the indivi- 

 dual tree. 

 The followng remarks apply only to seedling trees and not to 

 coppice shoots : — 



A. Growth in heiglit. 



The growth in height is at first nearly always very slight, and 

 in India remains so, according to the species and to the soil and 

 locality, for a period extending from 3 to 10 and even ] 5 and np 

 to 20 years. During this time the seedling is technically said to 

 be establishing itself. As soon as the seedling is thoroughly es- 

 tablished, the rate of ^owth in height increases rapidly, and 

 attains an annual maximum in a ccmparatively short time. In 

 Europe this maximum is attained in the case of pines and larch in 

 10-15 years, in the case of the spruce in 20^25 years, and in 

 the case of the beech and silver fir in 30 years. For India we have 

 unfortunately no exact figures, and owing to the continental 

 variety of its soils and climates, one and the same sjecies presents 

 extremely wide divergences. The maximum rate of growth only 

 lasts a short time. The rate sinks rapidly in the case of species 

 in which the maximum is attained early, more slowly in others, 

 nntU it is reduced to from 3 to 6 inches a year, at whicii figure 

 it keeps for a great number of years. A total cessation of growth 

 in height occurs only at a very advanced age, and earliest in iso. 

 lated trees. 



Rapidity of upward development reaches its maximum earliest 

 and be<nns to fall quickest in the most favourable soils and locali- 

 ties. In unfavourable localities, as on mountain ridges, the rate 

 at which a tree grows up remains nearly constant during its whole 

 life after it has once attained a certain figure. In youth and 

 middle awe the rapidity of growth in height in the most favourable 

 localities exceeds greatly that in unfavourable ones ; afterwards 

 there is but little difference. The height reached by trees in 

 nature crops is from two to three times as great in favourable loca- 



