PREFACE.   xiii

But his energies are reduced, and his means become inadequate to the task, and therefore no alternative is left him but to return while it is still possible for him to do so.

It is therefore not to be expected that any large part of the vast unexplored region before us will yield its secrets to a single traveller, but, rather, that they will become known step by step through various successive discoveries ; and as the experience of nearly a century corroborates these views, it is probable that for years to come there will still remain ample room in Africa for men inclined for adventure to carry out in them, if nowhere else, the metier of explorers.

FRANCIS GALTON.

8, ST. JAMES'S PLACE,

April2yth, x8s8.

V   h1

Y   ),ti

The four Mimosas that, to the exclusion of nearly every other tree
or bush, form the vegetation of Damaraland„