marked seasonal and diurnal changes which are characteristic of
lands in general. The summers are less stormy than the winters, but even
the summer temperatures are not high. Such an area as that of New
Zealand, with its mild climate and fairly regular rains, is really at
the margins of the zone, and has much more favourable conditions than
the islands farther south. These islands, in the heart of this zone,
have dull, cheerless and inhospitable climates. The zone enjoys a good
reputation for healthfulness, which fact has been ascribed chiefly to
the strong and active air movement, the relatively drier air than in
corresponding northern latitudes, and the cool summers. It must be
remembered, also, that the lands are mostly in the sub-tropical belt,
which possesses peculiar climatic advantages, as will be seen.

_Sub-tropical Belts: Mediterranean Climates._--At the tropical margins
of the temperate zones are the so-called sub-tropical belts. Their
rainfall regime is alternately that of the westerlies and of the trades.
They are thus associated, now with the temperate and now with the torrid
zones. In winter the equatorward migration of the great pressure and
wind systems brings these latitudes under the control of the westerlies,
whose frequent irregular storms give a moderate winter precipitation.
These winter rains are not steady and continuous, but are separated by
spells of fine sunny weather. The amounts vary greatly.[4] In summer,
when the trades are extended polewards by the outflowing equatorward
winds on the eastern side of the ocean anticyclones, mild, dry and
nearly continuous fair weather prevails, with general northerly winds.

The sub-tropical belts of winter rains and dry summers are not very
clearly defined. They are mainly limited to the western coasts of the
continents, and to the islands off these coasts in latitudes between
about 28 deg. and 40 deg.. The sub-tropical belt is exceptionally wide
in the old world, and reaches far inland there, embracing the countries
bordering on the Mediterranean in southern Europe and northern Africa,
and then extending eastward across the Dalmatian coast and the southern
part of the Balkan peninsula into Syria, Mesopotamia, Arabia north of
the tropic, Persia and the adjacent lands. The fact that the
Mediterranean countries are so generally included has led to the use of
the name "Mediterranean climate." Owing to the great irregularity of
topography and outline, the M