ing regions.

ALTITUDE. Coffee is found growing in all altitudes, from sea-level up to
the frost-line, which is about 6,000 feet in the tropics. _Robusta_ and
_liberica_ varieties of coffee do best in regions from sea-level up to
3,000 feet, while _arabica_ flourishes better at the higher levels.

Carvalho says that the coffee plant needs sun, but that a few hours
daily exposure is sufficient. Hilly ground has the advantage of offering
the choice of a suitable exposure, as the sun shines on it for only a
part of the day. Whether it is the early morning or the afternoon sun
that enables the plant to attain its optimum conditions is a question of
locality.

[Illustration: CROSS SECTION OF MOUNTAIN SLOPE IN YEMEN, ARABIA, SHOWING
COFFEE TERRACES

These miniature plantations are found chiefly along the caravan route
between Hodeida and Sanaa]

[Illustration: CLEARING VIRGIN FOREST FOR A COFFEE ESTATE IN MEXICO]

[Illustration: COFFEE NURSERY UNDER A BAMBOO ROOF IN COLOMBIA]

[Illustration: THE FIRST STEPS IN COFFEE GROWING]

In Mexico, Romero tells us, the highlands of Soconusco have the
advantage that the sun does not shine on the trees during the whole of
the day. On the higher slopes of the Cordilleras--from 2,500 feet above
sea-level--clouds prevail during the summer season, when the sun is
hottest, and are frequently present in the other seasons, after ten
o'clock in the morning. These keep the trees from being exposed to the
heat of the sun during the whole of the day. Perhaps to this
circumstance is due the superior excellence of certain coffees grown in
Mexico, Colombia, and Sumatra at an altitude of 3,000 feet to 4,000 feet
above sea-level.

Richard Spruce, the botanist, in his notes on South America, as quoted
by Alfred Russel Wallace,[315] refers to "a zone of the equatorial Andes
ranging between 4,000 and 6,000 feet altitude, where the best flavored
coffee is grown."

PROPAGATION. Coffee trees are grown most generally from seeds selected
from trees of known productivity and longevity; although in some parts
of the world propagation is done from shoots or cuttings. The seed
method is most general, however, the seeds being either propagated in
nursery beds, or planted at once in the spot where the mature tree is to
stand. In the latter case--called planting at stake--four or five seeds
are planted, much as corn is sown; and after germination, all but the
strongest plant are removed.

Where the nurser