bear for from twelve to fourteen years.

Another fungus, which Dr. Badham himself reared (_Polyporus
avellanus_), is procured by singeing, over a handful of straw, a block
of the cob-nut tree, which is then watered and put by. In about a
month the fungi make their appearance, and are quite white, of from
two to three inches in diameter, and excellent to eat, while their
profusion is sometimes so great as entirely to hide the wood from
whence they spring.[G] It has been said that _Boletus edulis_ may be
propagated by watering the ground with a watery infusion of the
plants, but we have no knowledge of this method having been pursued
with success.

The culture of truffles has been partially attempted, on the principle
that, in some occult manner, certain trees produced truffles beneath
their shade. It is true that truffles are found under trees of special
kinds, for Mr. Broome remarks that some trees appear more favourable
to the production of truffles than others. Oak and hornbeam are
specially mentioned; but, besides these, chestnut, birch, box, and
hazel are alluded to. He generally found _Tuber oestivum_ under
beech-trees, but also under hazel, _Tuber macrosporum_ under oaks, and
_Tuber brumale_ under oaks and abele. The men who collect truffles
for Covent Garden Market obtain them chiefly under beech, and in mixed
plantations of fir and beech.[H]

Some notion may be obtained of the extent to which the trade of
truffles is carried in France, when we learn that in the market of Apt
alone about 3,500 pounds of truffles are exposed for sale every week
during the height of the season, and the quantity sold during the
winter reaches upwards of 60,000 pounds, whilst the Department of
Vaucluse yields annually upwards of 60,000 pounds. It may be
interesting here to state that the value of truffles is so great in
Italy that precautions are taken against truffle poachers, much in the
same way as against game poachers in England. They train their dogs so
skilfully that, while they stand on the outside of the truffle
grounds, the dogs go in and dig for the fungi. Though there are
multitudes of species, they bring out those only which are of market
value. Some dogs, however, are employed by botanists, which will hunt
for any especial species that may be shown to them. The great
difficulty is to prevent them devouring the truffles, of which they
are very fond. The best dogs, indeed, are true retrievers.

The Count de Borch an