P.VET IV.] Caccl^ : Selection method of treatment in India. 319 
These and similar considerations would probably point to a fell- 
ing rotation of 8 to 12 years as the most suitable one. Or, to put it 
in the form of a general rule (a rule which has found great favour 
amongst European forestersj: The length of the felling rotation 
should he at least equal to the time taken for the crop to pats 
through one girth class. 
The size of the girth classes will naturally largely influence this 
period ; but it will also be found that certain other expedients may 
frequently be usefully employed, the better to enforce the rule above 
enunciated. Thus, the whole of the forest may be worked over 
twice during the course of the felling rotation; or, the richer por- 
tions of the area may be worked over twice and the poorer portions 
once. Or, the forest may be divided up into a suitable number of 
felling series with obvious advantages. 
The introduction of a felling rotation and the division of the area 
into a number of annual coupes, each of which is expected in its 
turn to yield the possibility of the whole area, naturally brings about 
certain abnormalities. In the first place, the constitution of the 
nelection forest is thereby considerably altered; it is evident that it 
must assume a condition intermediate between the true selection 
type and the regular type of forest, approaching nearer to the latter 
condition as the felling rotation is increased.* Again, if the area 
of the coupes is fixed, since in practice the stocking must necessaril * 
vary considerably in different parts of the area, it follows that too 
much will be removed from one couj>e, too little from another ; and , 
when the possibility is by volume, it will become impK)S5ible to make 
any distinction between the final and intermediate yields of the 
forest, the possibility being made up as best it can from either or 
both kinds of produce. Considerable difficulty will invariably be 
experienced in marking for fellings in a selection forest when the 
annual yield of the whole forest has to be obtained from a fixed 
coupe, an operation which leads to unsatisfactory and uneven mark- 
ing : either the end of the coupe being reached without having 
obtained the prescribed possibility, or a certain proportion of the 
area remaining unmarked. 
• EventoallT if the felling rotati<Hi becomes equal to the exploitable aze the 
forest woold assome the coorthtrtioa of a re^nlar forest. See also pa^es 227 and 
236, SchUch’E Maxmal of Forestry, Volnme III. 
D 
