perpendicularly from time to time along that coaft, are indications
that fufficieritly warrant this coneliifion.
It may alfo be obferved, with regard to the L’Aguillas Bank,
that the ftream of the current ftrikes ftrongeft juft along the
outer margin, which I fuppofe to have formerly been the old
coaft of Africa, not only becaufe the foundings along this
margin are deeper than on any other part of the bank, but becaufe
the bottom is fine white fand, fuch as is ufually found on
the fea ihores; and moft of the interior parts of the bank, and
efpecially where it approaches the proje£ting points of the
coaft, are compofed of rock, and the coarfe fragments of comminuted
fandftone.
But the ftrong arguments advanced in favour of the Cape
ifthmus having, at no great period of time, been covered with
the fea, refts on the fea-fliells that have been difcovered in the
fand that is accumulated on its furface. Such ihells may exift,
though I never faw them except on the ihores of the hays, but,
as. I have before obferved, whole ftrata of thefe may be found
buried in the fides of the Lion’s Hill, many hundred feet above
the level of the fea. Thefe ihells have not been brought into
that fituation by the waves of the ocean but by birds. There
is fcarcely a fheltered cavern in the fides of the mountains, that
rife immediately from the fea, where living ihell fifh may not
be found any day in the year. Crows even, and vultures, as
well as aquatic birds, detach the ihell-fifh from the rocks, and
mount with them in their beaks into the air; ihells thus carried
are faid to be frequently found on the very fummit even of
the
the Table Mountain. In one cavern, as I have already obferved,
at thé entrace of Moflel Bay, I difturbed fome thoufands
of birds, and found as many thoufands of living ihell-fiih
fçàttered on the furface of a heap of ihells that, for aught I
know, would have filled as many thoufand waggons. The
prefence of ihells therefore, in my opinion, is no argument for
the prefence of the fea.
We ihould not, perhaps, he faramifs in affigning to Africa
â prior creation to any of the other continents. Its vaft antiquity
appears in the very extraordinary manner in which the
fupérior parts of the great chain of mountains are corroded and
worn away; in the immenfely deep chafms in which the rills
Of water trickle down to the fea ; in the difappearance of the
water fupplied by the heavy fains ;'and, above all, in the complete
decompofitiori of thefeltfpar into a kind of femi-indurated
clay or lithomarga; and, as I have feen in frequent inftances,
pyramidal cryftals of quartz fo loofelv fixed by the bafe into
tnaifes of feltfpar as eafily to be drawn out with the fingers, and
when fo drawn out, appearing corroded, and wafted in their
tranfition to fome other ftate. 1
I would not here be underftood to fuppofe that the fea does
not retreat from the fhore ; on the contrary, it is a well eftabliihed
fâiï, that in fome parts of the world, and particularly in the
creeks of the Baltic, the fea has fubfided in a very remarkable
manner. But this retreat is partial and owing to local circum-
ftances. Had it been general, and in the fame degree as- has'
been obferved on the ihores of Bothnia, the ifthmus of Suez
K 2 muft