304 A FOREST TOUR AMONG THE DUNES OF GASCONY. 
sort of bottle shape, and consisting in some instances, of longi- 
tudinally detached fragments, through the interstices of which, 
light, entering on the opposite side of the tree, can be perceived. 
This bundle of sticks looks as if it would give way under the 
burden of the mighty crown which it contrives to support. M. 
Boppe had, however, something more important than this to which 
to call our attention, viz., the effect on the forest of this method 
of treatment, which, of course, since the tapping of every tree is 
continued until it dies, at a more or less advanced age, is almost 
exactly analagous to the selection method (jardinage). Here 
then was an excellent opportunity to observe the effects of this 
method of treating a species, which, like the cluster pine, has light 
cover. We certainly see a number of trees of all ages and sizes, 
some of them from 90 to 100 ft. high, and 12 to 13 ft. in girth ; 
but the ground is extremely badly stocked, much of it being com- 
pletely bare. When a forest is stocked with species of heavy 
cover, it is easy to keep trees of all ages growing together, for 
the taller ones do not interfere, by their shade, with the healthy 
growth of those which stand below them. But in the case of 
trees of light cover, it is impossible to obtain, by this system, any- 
thing but an extremely thin forest, for the young trees cannot 
maintain themselves alive under the shade of the older ones. For 
such species the regular system, with the age-classes grouped 
together, is the only one that can be successfully employed. 
On our way from Arcachon to Labouheyre we passed through 
some private forests, in which we saw a large number of kilns 
for burning pine wood into charcoal ; and we also inspected some 
ground which had, four years ago, been sown with a mixture of 
pine and broom, in lines 5 ft. apart. The young crop appeared 
to be in a flourishing condition. Near the forest house we saw 
some plantations of the cork oak (Q. occidentalis) and also of 
Quercus pedunculata. Some tea had also been sown as an experi- 
ment, but there does not appear to be much chance of its 
succeeding. 
TAPPING FoR REsIN. 
The cluster pine has large and abundant resin canals, the con- 
tents of which circulate much more freely in the sap wood than 
in the heart wood. In order to tap the tree, a cut, commenced 
near its base, is carried gradually upwards to a height of about 
123 ft., but more rarely to 15 or 16 ft., and the resin, flowing 
