Concholepas from the height of about one hundred feet, I found that it was
in considerable part composed of minute fragments of the spines, mouth-
bones, and shells of Echini, and of minute fragments, of chiefly very young
Patellae, Mytili, and other species. I found similar microscopical
fragments in earth filling up the central orifices of some large
Fissurellae. This earth when crushed emits a sickly smell, precisely like
that from garden-mould mixed with guano. The earth accidentally preserved
within the shells, from the greater heights, has the same general
appearance, but it is a little redder; it emits the same smell when rubbed,
but I was unable to detect with certainty any marine remains in it. This
earth resembles in general appearance, as before remarked, that capping the
rocks of Quiriquina in the Bay of Concepcion, on which beds of sea-shells
lay. I have, also, shown that the black, peaty soil, in which the shells at
the height of 350 feet at Chiloe were packed, contained many minute
fragments of marine animals. These facts appear to me interesting, as they
show that soils, which would naturally be considered of purely terrestrial
nature, may owe their origin in chief part to the sea.

Being well aware from what I have seen at Chiloe and in Tierra del Fuego,
that vast quantities of shells are carried, during successive ages, far
inland, where the inhabitants chiefly subsist on these productions, I am
bound to state that at greater heights than 557 feet, where the number of
very young and small shells proved that they had not been carried up for
food, the only evidence of the shells having been naturally left by the
sea, consists in their invariable and uniform appearance of extreme
antiquity--in the distance of some of the places from the coast, in others
being inaccessible from the nearest part of the beach, and in the absence
of fresh water for men to drink--in the shells NOT LYING IN HEAPS,--and,
lastly, in the close similarity of the soil in which they are embedded, to
that which lower down can be unequivocally shown to be in great part formed