United Kingdom is about 50,000,000 lb per annum;
about one-fifth only is produced in the British empire, and of this
about nineteen-twentieths come from India and one-twentieth from the
British West Indies.

_Coffee-leaf Disease._--The coffee industry in Ceylon was ruined by the
attack of a fungoid disease (_Hemileia vastatrix_) known as the Ceylon
coffee-leaf disease. This has since extended its ravages into every
coffee-producing country in the Old World, and added greatly to the
difficulties of successful cultivation. The fungus is a microscopic one,
the minute spores of which, carried by the wind, settle and germinate
upon the leaves of the plant. The fungal growth spreads through the
substance to the leaf, robbing the leaf of its nourishment and causing
it to wither and fall. An infected plantation may be cleansed, and the
fungus in its nascent state destroyed, by powdering the trees with a
mixture of lime and sulphur, but, unless the access of fresh spores
brought by the wind can be arrested, the plantations may be readily
reinfected when the lime and sulphur are washed off by rain. The
separation of plantations by belts of trees to windward is suggested as
a check to the spread of the disease.

[Illustration: FIG. 2.--Coffee-leaf Disease, _Hemileia vastatrix_.

1, Part of leaf showing diseased patches.
2, Cluster of uredospores.
3, Transverse section of a diseased patch in the leaf showing the
hyphae of the fungus pushing between the leaf-cells and tapping
them for nourishment. The hyphae have broken through in the upper
face and are forming a cluster of spores.
4, Ripe uredospores.
5, A teleutospore.
6, A uredospore germinating, the germ-tube is penetrating the leaf.
7, Uredospore germinating.
u, Uredospore.
t, Teleutospore.
2-7, Highly magnified.]

_Microscopic Structure._--Raw coffee seeds are tough and horny in
structure, and are devoid of the peculiar aroma and taste which are so
characteristic of the roasted seeds. The minute structure of coffee
allows it to be readily recognized by means of the microscope, and as
roasting does not destroy its distinguishing peculiarities, microscopic
examination forms the readiest means of determining the genuineness of
any sample. The substance of the seed, according to Dr Hassall, consists
"of an assemblage of vesicles or cells of an angular form, which adhere
so firmly together that they break up into pieces rather than separa