Lyell has shown that it is hardly possible to resist the evidence on this head in the case of the several tertiary stages; and every year tends to fill up the blanks between them, and to make the percentage system of lost and new forms more gradual
. In some of the most recent beds, though undoubtedly of high antiquity if measured by years, only one or two species are lost forms, and only one or two are new forms, having here appeared for the first time, either locally, or, as far as we know, on the face of the earth.
It is impossible here to give the reasons, but I am convinced that the shingle terraces were accumulated, during the gradual
elevation of the Cordillera, by the torrents delivering, at successive levels, their detritus on the beachheads of long narrow arms of the sea, first high up the valleys, then lower and lower down as the land slowly rose.
Nor, considered aright, does it seem any argument in favor of the gradual
extinction of the Sperm Whale, for example, that in former years (the latter part of the last century, say) these Leviathans, in small pods, were encountered much oftener than at present, and, in consequence, the voyages were not so prolonged, and were also much more remunerative.
The intimacy between her and Emma must sink; their friendship must change into a calmer sort of goodwill; and, fortunately, what ought to be, and must be, seemed already beginning, and in the most gradual
, natural manner.
The second object aimed at by the Bill was the gradual
demoralization of the Circles themselves.