by any diluvial catastrophe, but was the result of a change in
the relative activities of certain natural operations which are
quietly going on now; and that, since the level of the mere
began to sink, many thousand years ago, no serious catastrophe
of any description has affected the valley.

The evidence that the Jordan-Arabah valley really was once
filled with water, the surface of which reached within 160 feet
of the level of the pass of Jezrael, and possibly stood higher,
is this: Remains of alluvial strata, containing shells of the
freshwater mollusks which still inhabit the valley, worn down
into terraces by waves which long rippled at the same level, and
furrowed by the channels excavated by modern rainfalls, have
been found at the former height; and they are repeated, at
intervals, lower down, until the Ghor, or plain of the Jordan,
itself an alluvial deposit, is reached. These strata attain a
considerable thickness; and they indicate that the epoch at
which the freshwater mere of Palestine reached its highest level
is extremely remote; that its diminution has taken place very
slowly, and with periods of rest, during which the first formed
deposits were cut down into terraces. This conclusion is
strikingly borne out by other facts. A volcanic region stretches
from Galilee to Gilead and the Hauran, on each side of the
northern end of the valley. Some of the streams of basaltic lava
which have been thrown out from its craters and clefts in times
of which history has no record, have run athwart the course of
the Jordan itself, or of that of some of its tributary streams.
The lava streams, therefore, must be of later date than the
depressions they fill. And yet, where they have thus temporarily
dammed the Jordan and the Jermuk, these streams have had time to