It is surrounded by (I) a thin-walled, smaller-celled hydrom mantle; (2) an amylom sheath; (3) a leptom mantle, interrupted here and there by starch cells.
The margin of the Red Sea itself consists, on the Arabian side, of a strip of low plain backed by ranges of barren hills of coral and sand formation, and here and there by mountains of considerable height.
It generally consists of limestone, or of mixed limestone and clay, or of sand and clay, or of gravel, with here and there flint and rolled quartz.
Vast and impenetrable forests, impassable marches and thickets, numerous lakes, swampy meadows, with cleared and dry spaces here and there occupied by villages, are the leading features of this region.
Where the way was formed on the level, drains were cut on each side of the intended line, and were intersected here and there by cross drains, by which the upper part of the moss was rendered dry and firm.
