Part IV.] Caccia: Selection method of treatment in India. 317 
It will readily be admitted that the number of trees which should 
be ftniiid in eadi normal diameter-class must increase considerably 
in each sticcessive lower class. That is to say, to produce “n” 
first class trees it will require more than “ n ” second class trees and 
a far greater number of third class trees; and so on. lint tJie exact 
proportion between the number of trees to be found in each succes- 
sive diameter-class in a normal selection forest still remains unde- 
termined. The view most recently expressed in France, from the 
stiidy of all available data collected with the object of solving this 
very question, appears to be that there exists for each forest a 
constant ratio between the number of trees in the successive dia- 
meter-classes. That is to say, if x ” be the constant, there will 
be required in the normal selection forest in order to produce one 
first class tree, x, 2nd class trees; , 3rd class trees; x^ , 4th class 
trees; and so on. And this constant is said to vary in the different 
French selection forests between 1‘25 and 1‘45, for diameter classes 
differing by 5 centimeters. 
It is difficult to say how far these figures are applicable to India ; 
as so far, with one exception, no attempt appears to have been 
made to arrive at a conception of the constitution of the normal 
selection forest from the study of existing forests.* The one excep- 
tion above referred to relates to certain figures noted by Mr. F. xi. 
Leete, I.F.S., in his working plan for the sal forests of the Kheri 
Division, and these yield the following results fthe diameter-classes 
being unfortunately extremely large). 
Girth. 
Number of trees 
in a normal 
series. 
Ratio between the number of 
trees in successive girth 
classes of a normal series. 
6' & over .... 
1 
4F-6' 
1-23 
1-23 
3'-4^' .... 
1-61 
1-30 
.\gain turning to the average number of sal stems of different 
girth-classes found to exist in such sal forests as have been enumer- 
ated, the following results are obtained: — t 
* Vol. II of Huffel’s “ Economic Forestiere ” should be consulted on this subject. 
It, cannot be said that Prof. Huft'el’s figures are altogether convincing; but thev 
may be accepted as forming an interesting basis of investigation. 
t See page 205 of Indian Forest Records, Vol. 1, Part I, Calcutta : Superinten 
dent of Government Printing. India. 
