THE CORK TREE. 557 
In poor land the holes in which the trees are to be placed should be 
dug at least six months beforehand in order to permit the soil to become 
mellow. In good land there is no need to dig the holes until ready to 
plant the trees. The holes should be large enough to admit the roots 
without touching the sides. A slight hollow, which should be filled with 
_ water after planting, should be left around each tree. 
The trees ought to be at such a distance apart as to insure a full sup- 
ply of air and an abundance of light; but not so much as to favor the 
growth of shrubs prejudicial to the trees, or to permit the ground to dry 
too much. Practical experience, an acquaintance with the locality, and 
a knowledge of vegetable physiology are the surest guides to depend 
upon to obtain the best results. As a general rule the number of trees 
per hectare (2.471 acres) should be from 150 to 250. 
Old trees should be cut down to make room for young ones. Duha- 
mel and other authorities have fixed the age at which cork trees should 
be felled at 150 years. This rule should not be applied in the province 
ot Gerona, however, as the trees there are often valuable and yield a 
good product for forty or fifty years after reaching the age stated. 
GATHERING THE CORK CROP. 
The operation of taking off the cork, although it inflicts a real disease 
upon the tree, facilitates, nevertheless, the development of the trunk 
and the production of the coats of cork. The cork should be taken off 
when the sap is running. Mr. Lambert is in favor of having this work 
performed in the spring, because at that time, in addition to the fact 
that the cork is removed with greater ease than in the depth of summer, 
the new formation of the cork which is not yet matured, and which is use- 
less for manufacturing purposes, is not removed. The inner bark also 
is not so liable to dry up and separate from the tree. Some cork grow- 
ers, however, prefer to take off the cork during the months of July and 
August, when the sap is descending. Along the coast in the province 
of Gerona, this work is generally done about the last of June to the first 
of July, the operation being begtin when the cork readily separates from 
the tree. 
The greatest risk in taking off the cork in the spring is, perhaps, in 
the danger of tearing away part of the inner bark, in addition to the 
further danger incurred from late frosts which might kill the tree. It 
should be so arranged, therefore, if possible, that the newly stripped 
cork trees, which are then covered with an abundant exudation of sap, 
should not be exposed to sudden changes of temperature, particularly 
to the cold winds which follow the autumn rains. 
The trees should be stripped for the first time when the outer cover- 
ing can be taken off without injuring them. In the province of Gerona 
this is done when the trees are from 2 to 4 inches in diameter. This 
rule is not strictly adhered to, however, and it is not rare to see even 
smaller trees denuded of their covering. The first and sometimes the 
second coats of cork are of no value to make stoppers. 
After the trees arrive at maturity, that is to say, when they begin to 
yield cork of mercantile value, it is of great importance to determine 
the proper period that should be allowed to elapse between the har- 
vests. In the province of Gerona the majority of the growers strip 
their trees every ten years, while some do so every twelve years. Cases 
are mentioned where the cork was permitted to grow for eighteen years, 
and then gave a handsome return to the grower. As cork sufficiently 
thick to make champagne-stoppers is worth more than any other, grow- 
