from which they totally differ in character and aspect. These valleys
are called the Sierra. The inhabitants of Lima usually comprehend under
the term Sierra, the whole interior of Peru, and every Indian who is not
an inhabitant of the coast, or of the forest regions, is called by them
a _Serrano_. But strictly speaking, the Sierra includes only the valleys
between the Cordillera and the Andes, and I shall here use the term in
its more limited and proper sense.

In the Sierra there are only two seasons throughout the year. The winter
or rainy season commences in October; but the rains are neither so heavy
nor so continuous as in the forest districts. The falls of rain seldom
last longer than two or three days in succession. Storms of thunder and
lightning are very frequent in the Sierra; they are not accompanied by
snow as in the Puna, but often by hail. The thermometer never falls
below +4 deg. R., and during the daytime it is on the average at +11 deg. R. In
April the summer season sets in, bringing with it an uninterrupted
succession of warm bright days. The nights in summer are colder than in
winter. In a summer night the thermometer will sometimes fall below
freezing point, and the cold is often very severe. About noon the heat
is oppressive, though the average heat of the day does not exceed 13, 9 deg.
R. During the summer season the horizon is frequently obscured by heavy
dark clouds, which seldom break over the valleys, but continue frowning
over the hills. The natives call these portentous clouds _Misti
Manchari_ (terror of the whites),[76] because the inhabitants of the
coast always regard them as indicative of stormy weather.

The climate of the Sierra favors the natural fruitfulness of the soil,
which richly repays the labor of the husbandman; but plants, peculiar to
the warm tropical regions, do not thrive well here. Prior to the
European emigration to Peru, only maize, quinua (_Chenopodium Quinoa_,
L.), and a few tuberous roots were grown in the Sierra; but since the
Spanish conquest, the European cereals, lucerne, and various kinds of
vegetables are cultivated with perfect success. But the eye of the
traveller seeks in vain for those stately forests which clothe the
mountainous districts of Europe; the barren acclivities afford nurture
only for the agave-tree, and some very large species of cactus. Groups
of willow trees (_Salix Humboldtii_), which attain the height of about
twenty or twenty-five feet, t