SAND IN THE MEDITERRANEAN. 549 
and gravel carried into the Mediterranean by the torrents of the 
Maritime Alps, the Ligurian Apennines, the islands of Corsica, 
Sardinia, and Sicily, and the mountains of Calabria, is appa- 
rently great. In mere mass, it is possible, if not probable, that 
as much rocky material, more or less comminuted, is contributed 
to the basin of the Mediterranean by Europe, even excluding 
the shores of the Adriatic and the Euxine, as is washed up from 
it upon the coasts of Northern Africa and Syria. A great part 
of this material is thrown out again by the waves on the Euro- 
pean shores of that sea. The harbors of Luni, Albenga, San 
Remo, and Savona west of Genoa, and of Porto Fino on the 
other side, are filling up,and the coast near Carrara and Massa 
is said to have advanced upon the sea to a distance of 475 feet 
in thirty-three years.* Besides this, we have no evidence of the 
existence of deep-water currents in the Mediterranean, extensive 
enough and strong enough to transport quartzose sand across 
with very short courses, for the sea-waves in many parts of the peninsular 
coast wash the base of the mountains. In these cases, the debris of the rocks 
do not reach the sea in a sufficiently comminuted condition to be entitled to 
the appellation of sand, or even in the form of well-rounded pebbles. The 
fragments retain their annular shape, and, at some points on the coast, they be- 
come cemented together by lime or other binding substances held in solution 
or mechanical suspension in the sea-water, and are so rapidly converted into 
a singularly heterogeneous conglomerate, that one deposit seems to be con- 
solidated into a breccia before the next winter’s torrents cover it with an- 
other. 
In the northern part of the peninsula there are extensive deposits of sand 
intermingled with agate pebbles and petrified wood, but these are evidently 
neither derived from the Sinaitic group, nor products of local causes known 
to be now in action. 
I may here notice the often repeated but mistaken assertion, that the petri- 
fied wood of the Western Arabian desert consists wholly of the stems of palms, 
or at least of endogenous vegetables. This is an error. I have myself 
picked up in that desert, within the space of a very few square yards, frag- 
ments apparently of fossil palms, and of at least two petrified trees distinctly 
marked as of exogenous growth both by annular structure and by knots. In 
ligneous character, one of these almost precisely resembles the grain of the 
extant beech, and this specimen was worm-eaten before it was converted into 
silex. 
* BorrcER, Das Mittelmeer, p. 128. 
