THE TEMPLE OF SERAPIS. 11 
daily washed by the tide. Earthquakes had been repeatedly 
remarked by the inhabitants, so that Darwin no longer doubted 
concerning the cause which made the trees to fali, and the 
store-house to be washed by the daily tide. 
On the columns of the temple of Serapis, near Puzzuoli, the 
astonished naturalist sees holes scooped out by Pholades and 
Lithodomas, twenty-four feet above the present level of the sea. 
These animals are marine testacea, that have the power of 
burying themselves in stone, and cannot live beyond the reach 
of low-water. How then have they been able to scoop out those 
hieroglyphic marks so far above the level of their usual abodes ? 
for surely marble originally defective was never used for the 
construction of so proud an edifice. Alternate depressions and 
elevations of the soil afford us the only key to the enigma. 
Earthquakes and oscillations, so frequent in that volcanic region, 
must first have lowered the temple into the sea, where it was 
acted upon by the sacrilegious molluscs, and then again their 
upheaving powers must have raised it to its present elevation. 
Thus, even the solid earth changes its features, and reminds 
us of the mutability of all created things. 
There can be no doubt that, in consequence of the perpetual 
increase of alluvial deposits, and of the volcanic processes I have 
mentioned, the present boundaries of ocean must undergo great 
alterations in the course of centuries, and the general level of 
the sea must either rise or fall; but the evidence of history proves 
to us that, for the last 2000 years at least, there has been no 
notable change in this respect. 
The baths hewn out in the rocks of Alexandria, and the stones 
of its harbour, have remained unaltered ever since the founda- 
tion of the city by the Macedonian conqueror; and the ancient 
port of Marseilles shows no more signs of a change of level than the 
old sea-walls of Cadiz. Thus, all the elevations and depressions 
that have occurred in the bed of ocean, or along its margin, 
and all the mud and sand that thousands of rivers continually 
carry along with them into the sea, have left its general level 
unaltered, at least within the historic ages. However great their 
effects may appear to the eye that confines itself to local changes, 
their influence, as far as the evidence of history reaches, has 
been but slight upon the immensity of the sea. 
Geodesical operations have proved that the level of the ocean, 
