In the Lebanon, according to Dr.

Hooker, perpetual snow formerly covered the central axis, and fed glaciers which rolled 4,000 feet down the valleys.

The same observer has recently found great moraines at a low level on the Atlas range in North Africa.

Along the Himalaya, at points 900 miles apart, glaciers have left the marks of their former low descent; and in Sikkim, Dr.

Hooker saw maize growing on ancient and gigantic moraines.