196 
Indian Forest Records. 
[VOL. I. 
Section 3. — Development of the Crown. 
Rules which govern the development of the crown of trees in general : — 
1. The proportion of the crown to the total volume of at ree varies very 
considerably with the age of the tree, and the conditions under 
which it has grown. 
II. For equal heights and equal girths, old trees have proportionately 
smaller crowns than young trees. 
III. For equal girths, the proportion of branch wood diminishes with the 
height ; whilst for equal heights, the proportion of branch wood 
increases with the diameter. 
IV. The volume of the crown may be taken as equal to 60, 30 or 15 per cent. 
of the volume of the stem, according as to whether the length of 
clear bole is one-quarter, one-half, or three-quarters of the total 
height of the tree.* 
The proportion of branch wood in a tree grown in a crowded wood, 
calculated for trees of different heights may be expressed either in terms 
of the total volume of the tree, or of the length of clear bole ; but so 
far no data are available for the Sal. 
Section 4. — Development of the Bark. 
Laws which govern the development of the bark of trees in general : — 
I. The greater the diameter of the stem, the older the tree, the poorer the 
quality of the locality, the more isolated the tree : the thicker the 
bark. 
II. The bark is thicker at the base of the trunk than at the extremities. 
III. The growth in thickness of the bark is extremely slow as compared with 
the diameter increment of the stem ; so that, as the stem increases in 
diameter, the ratio between volume of bark and total volume of 
tree diminishes. 
Sal bark has not so far been exported to any extent ; but, as a result 
of recent enquiries, it may attain value for tanning purposes. The pre- 
paration of yield tables, giving the weight, volume, or percentage of 
green and dried bark that may be expected from Sal trees of different 
girths will then become a matter of some importance. 
The follomng table,')' the result of the measurement of a large num- 
ber of logs, gives the average thickness of bark to be found along the 
length of a well-shaped Sal stem : — 
*Ges>;tz der Stamm bildung. Pressler. 
fWorking-Plan for the Trans-Sarda forests 63 ' .Mr. F. A. Leete, I.F.S. 
