59 



from the youngest 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 10 being 

 produced by the crop. This can be settled only by investigation* 

 in the crop itself. 



4. General remarks on the count? of rtertlnfiment of the imliti- 



dual tree* 

 The following remarks apply only to seedling trees and not to 



coppice shoots : 



A. Growth in height. 



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 15 and up 



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



be establishing itself. As soon as the seedling is thoroughly e*. 



tablished, the rate of growth in height increases rapidly, and 



attains an annual maximum in a comparatively 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 species 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, 



until it is reduced to from 3 to 6 inches a year, at which figure 



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



in height occurs only at a very advanced nge, and earliest in wo. 



lated trees. 



Rapidity of upward development reaches it* maximum earliest 

 and begins to fall quickest in the most favourable soils and locali- 

 ties. In unfavourable localities, as on mountain ridres, 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 age the rapidity of growth in height in the mo*t favourable 

 localities exceeds greatly that in unfavourable ones ; afterward* 

 there is but little difference. The height reached by tree* in 

 mature crops is from two to three times as great in favourable!** 



