o for many days without drinking.
Ostriches cover great distances to reach water before it is too late.
Plants are provided with huge roots that they may suck up as much
moisture as possible, and many of them bear thorns and spikes instead of
leaves so that the evaporation may be insignificant. Many of them are
called to life by a single fall of rain, develop in a few weeks, and die
when long drought sets in again. Then the seeds are left, waiting
patiently for the next rain. Some desert plants seem quite dead, grey,
dried-up, and buried in dust, but when rain comes they send out green
shoots again.

Every river bed is called in the Sahara a _wadi_. Very seldom does a
trickle of water run down it after rain, but in these beds the
vegetation is richer than elsewhere, for here moisture lingers longer
than in other spots. Many caravans march along them, and gazelles and
antelopes find pasture here.

A European leaves Algeria to make his way into the Sahara with an
incomprehensible feeling of fascination. In the French towns on the
Mediterranean coast he has lived just as in Europe. He has been able to
cross by train the forest-clad heights of the Atlas Mountains, where
clear brooks murmur among the trees. He leaves the railway behind, and
finds the hills barer the farther he travels south. At last the
monotonous, slightly undulating desert stretches before him, and he
feels the magical attraction of the Sahara drawing him deeper and deeper
into its great silence and solitude. All the colours become subdued and
greyish-yellow, like the lion's hide. Everything is yellow and grey,
even the dromedaries which carry him, his tent and baggage, from well to
well. He can hardly tell why he finds this country pleasanter than the
forests and streams on the slopes of the Atlas Mountains; perhaps owing
to the immense distances, the mysterious horizon afar off, the blood-red
sunsets, the grand silence which prevails everywhere so that he hardly
dares speak aloud. It is the magic of the desert that has got hold of
him.

Thirty years ago a large French expedition, under the command of Colonel
Flatters, marched along this route from Algeria southwards through the
Sahara. It consisted of a hundred men, including seven French officers
and some non-commissioned officers, and its equipment and provisions
were carried by three hundred dromedaries. The French Government had
sent out the expedition to examine the Tuaregs' country, and to mark