Ulvaceae and dictyoteae, with
stems and green leaves, which float on the ocean, have vegetated on
rocks near the surface of the water?
From some notions which the captain of the Pizarro had collected in
an old Portuguese itinerary, he thought himself opposite to a small
fort, situated north of Teguisa, the capital of the island of
Lancerota. Mistaking a rock of basalt for a castle, he saluted it
by hoisting the Spanish flag, and sent a boat with an officer to
inquire of the commandant whether any English vessels were cruising
in the roads. We were not a little surprised to learn that the land
which we had considered as a prolongation of the coast of
Lancerota, was the small island of Graciosa, and that for several
leagues there was not an inhabited place. We took advantage of the
boat to survey the land, which enclosed a large bay.
The small part of the island of Graciosa which we traversed,
resembles those promontories of lava seen near Naples, between
Portici and Torre del Greco. The rocks are naked, with no marks of
vegetation, and scarcely any of vegetable soil. A few crustaceous
lichen-like variolariae, leprariae, and urceorariae, were scattered
about upon the basalts. The lavas which are not covered with
volcanic ashes remain for ages without any appearance of
vegetation.
