Pakt IV. j Caccia : Selection method of treatment in India. 331 
proposed to restrict the fellings of sound Nahor trees 6 feet in girth and over 
during the first eight years to one-fourth of the total number of such trees in 
compartments 1-8. The only way to secure the observance of this restriction 
with the present untrained staff is to provide that for every sound Nahor tree 
6 feet in girth and over for felling, three such trees must be marked for reserva- 
tion. Accordingly, the marking of Nahor trees for felling in compartments 1-8 
is subject to the following conditions : — 
(1) Before any sound Nahor trees are marked, all dead, dying, and 
unsound trees over 4 feet in girth must be marked for felling. 
(2) No sound Nahor trees below 6 feet in girth may be marked for 
felling. 
(3) No isolated sound Nahor tree 6 feet in girth or over may be marked 
for felling if there is no young growth coming up round it. 
(4) For every sound Nahor tree 6 feet in girth and over marked for felling, 
three such trees must be marked for reservation. 
Section 2. — Possibility by Number of Trees. 
Tlie main disadvantage of prescribing a possibility by number 
of trees lies in an unequal return : and on this account the method 
has been almost wholly discarded in Europe. The impossibility of 
fixing a yield by number of trees which would include both primary 
and intermediate produce (as can be done with a volume possibility) 
is only too apparent ; and even if a girth be arbitrarily fixed (as is 
usually done) in order to separate the Final Yield (counting against 
the possibility) from the Intermediate Yield, the returns must still 
vary considerably, especially since the girth so fixed must frequently 
vary with the species and with the locality. 
Nevertheless under the conditions usually prevailing in India a 
possibility fixed by number of trees is the only practical one. In the 
first place, its greater simplicity highly commends it : but, in ad- 
dition, when as is usually the case only trees of large size are sale- 
able ; when only one species in a mixed forest is exploitable ; when 
the establishment is small, untrained, and the cost of valuation sur- 
veys is prohibitive ; when an absolutely equal yearly volume return 
is not desired, a possibility by number of trees appears to fully meet 
all such requirements. 
The possibility by number of trees may be calculated in a variety 
of different ways. Many of these methods have been devised in 
India to meet local conditions, and though these may differ only to 
