with in the successive beds would, looking at them broadly, be the more
different the further that I went down. Or, in other words, inasmuch
as we started with the clear principle, that in a series of
naturally-disposed mud beds the lowest are the oldest, we should come
to this result, that the further we go back in time the more difference
exists between the animal and vegetable life of an epoch and that which
now exists. That was the conclusion to which I wished to bring you at
the end of this Lecture.