24 
eastern aspect. The first effect of close planting is noticeable in 
the exaggerated upward growth of the trees, which, finding that their 
branches if extended laterally meet with the branches of neighbouring 
trees, attempt to overtop their neighbours with the result that their 
branches are drawn upwards, giving the trees tlie appearance of 
bundles of birch twigs. 
Food that could be utilized in the thickening and rounding out 
of the trunk is used to build up length of branches and trunk, 
because, in the struggle for sunlight, each tree tries to overtop its 
neighbour. In consequence, an activity of no profitable use to tlie 
planter is induced. By giving the tree more space it s. ill grow 
outward as well as upward and in a normal, evenly distributed 
growth. Let it be emphasized that thinning out to be most 
beneficial should be done before the “ drawing up ” stage lias set 
in. Very little lateral branching will be induced in an old tree 
whose early environment has been an overcrowded estate. 
I do not think it necessary to say anything further regarding 
the effect of sunlight on the branch growth. The effect on the depth 
of bai'k is equally noticeable and although it does not follow that a 
thin bark will necessarily yield less latex than a thicker bark it is 
extremely probable that coolies in getting the latex will touch tlie 
cambium and cause wounds over which the renewed bark will be 
poorer still. We may, therefore, take it as granted that a tree which 
has room for normal development as regards branch growth will 
prove more healthy than that v'hich is retarded and that as a 
corrollary the yield from such a tree should be greater and the 
bark renewal better. 
The second point is the great economy which is effected. The 
urTit which is generally taken as a basis of all calculations is the 
yield per acre. If you can get a high yield per acre from a compara- 
tively small number of highly yielding trees it is obviously more 
economical than if you got the same yield per acre from a closely 
planted estate. I think I may take a yield of 450 lbs. per acre as one 
likely to satisfy directors and shareholders, and to make every point 
quite clear we will take a suppositional case of two estates of 500 
acres, one of which is planted with 80 trees to the acre and one with 
160 trees to the acre — other factors being the same — a reasonable task 
being 400 trees per cooly. With a check-roll average of 40 cents 
the cost of collecting will be : 
A. 100 coolies x 350 days x 40 cents _ say, 6.2 cents per lb. 
225,000 Labour only 
B. 200 coolies x 350 days x 40 cents m . , . 
_____ = Twice the above 
It has often been argued that in a widely planted clearing coolies 
would not be able to do the same task. In practise this is not the case, 
the work of tapping and collecting takes up the time, not the distance 
