510 A FOREST TOUR AMONG THE DUNES OF GASCONY, 
of the forest that we entered first is of pure oak, forty years old, 
and about 50 ft. high ; it is to be felled at the age of one hundred 
and twenty years. We remarked at once that the trees had an 
unhealthy appearance. They were much branched, and had 
crooked stems, covered with twigs (branches gowrmandes) and 
lichen up to “ high-water mark.” Many of the larger branches 
were dead, while the stems were, in numerous instances, split by 
the action of frost; and it was evident that they required the 
protection of a lower stage of forest growth, which would remedy 
many of the existing defects. There were no seedlings on the 
ground, which was covered, in places, with ferns, brambles, a 
little gorse, and “ butchers’ broom” (Ruscus aculeatus). The 
forest is heavily grazed over by cows and bullocks, which, how- 
ever, do comparatively little harm, because the inundations, which 
leave a deposit of fresh soil behind them, prevent the ground from 
becoming hardened by the animals’ feet. M. Boppe remarked 
that natural regeneration is here very easy to obtain, for the oak 
gives seed every year, a plentiful crop occurring every second 
year ; and the soil being extremely fertile, growth is rapid. But 
the old difficulty of treating a species of light cover as a pure 
forest has to be encountered; if the trees stand too thickly 
together, they grow up tall and thin, and many branches die ; 
while, if heavy thinnings are made after considerable intervals of 
time, there is a large development of twigs on the stems. The 
treatment of such a forest is a very delicate operation, requiring 
much skill ; and the only way to achieve success, is to make light 
thinnings frequently. If this be not done the forest will, in all 
probability, be ruined. If it were possible to introduce a mixture 
of hornbeam, which, unfortunately, does not succeed here, this 
tree would serve to protect both the ground and the stems of the 
oaks, without interfering with their crowns; and heavier thin- 
nings, which would have a very favourable effect, could then be 
made among them. There are no kinds of harmful insects in this 
forest, probably owing to the periodical inundation of the ground. 
Passing on, we traversed a younger portion of forest, where the 
oak is mixed with a few elms and maples (Acer campestris) ; and, 
leaving this, we entered a block, in which the final fellings had 
been made, from two to five years previously. Here the rapid 
growth of the young trees was very remarkable ; those five years 
old having a height of 6 or 7 ft. The ground was densely covered, 
not only by young oaks, but also by a mass of tangled shrubs and 
