[3] Posidonius, who himself divides the earth into zones, tells us that
five is the number best suited for the explanation of the celestial appearances, two of these are periscii,
1
which reach from the poles to the point where the tropics serve for Arctic Circles; two more are heteroscii,
2
which extend from the former to the inhabitants of the tropics, and one between the tropics, which is called amrphiscius,
3
but for matters relative to the earth, it is convenient to suppose two other narrow zones placed under the tropics, and divided by then into two halves, over which [every year] for the space of a fortnight, the sun is vertical.
4
These zones are remarkable for being extremely arid and sandy, producing no vegetation with the exception of silphium,
5
and a parched grain somewhat resembling wheat. This is caused by there being no mountains to attract the clouds and produce rain, nor any rivers flowing
6
through the country. The consequence is that the various species
7
are born with woolly hair, crumpled horns, protruding lips, and wide nostrils; their extremities being as, it were gnarled. Within these zones also dwell the Ichthyophagi.
8
He further remarks, that these peculiarities are quite sufficient to distinguish the zones in question: those which are farther south having a more salubrious atmosphere, and being more fruitful and better supplied with water.