192
THE USES OF FUNGI.
be bought in London for about two shillings a pound—shows that
the wealth brought to the country by the mushroom alone is almost
equal to an addition of a penny to the income tax.
Nor is the mushroom the only representative among fungi of com-
mercial importance in a similar respect. We in England have little con-
ception of the quantity of dried Boletus edulis which, under the name
of "seps," is produced and consumed on the Continent of Europe,
especially in Germany and Austria. It is as universal as a condiment
there as onions are here.
Those who appreciate pate de foie gras—and who that has tasted
it does not ?—know that the charm of the flavour of those poor geese,
whose livers have gone to make the substratum of the commodity,
lies in the admixture of chopped truffles, those black masses which,
when we get them, have given most of their aroma to the meat about
them. The importation of this comparatively cheap luxury increases
every year. Somebody must get a profit out of it, and the office of a
truffle gatherer, if it do not become year by year more remunerative,
must continually add to the wealth of a wider circle ; for civilization
is not likely to lead to the loss of a taste for truffles.
Morels again have a commercial importance. It does not seem
to be necessary to be much of a botanist to make money out of
them wherever they grow; once seen, there is nothing with which
they can be confounded. There are few other plants which ever
reach the value of a shilling an ounce, as morels are said to do.
And yet they only require to be known, to be gathered and utilised.
But I have only touched upon the fringe of my subject yet.
When I say, as I may do unhesitatingly, that the whole produce of
our brewers' vats and of the wine-makers' casks, is a function of a
fungus, I open to you the importance of fungi to the world. Some
of us may be teetotallers, but none of us can be blind to the fact
that a vast proportion of the country's revenue is derived from beer
and wine and spirits. It is from the presence of yeast that grapes
and barley, to take only the most prominent instances, obtain their
power over mankind. Fermentation, according to our present
knowledge, cannot take place without yeast. And we know that
yeast, or barm, is a fungus, Torula or Saccharomyces cerevisiae. No
one nowadays doubts that it is the yeast, or some constituent of the
yeast, which somehow or other causes the sugar in the grape-juice
or the wort to break up into alcohol, carbonic acid, glycerine, succinic
acid, and who knows how many volatile ethers and other substances.