at botanical species are only a higher and more permanent
class of varieties." He extends the same view to animals. The dean
believes that single species of each genus were created in an originally
highly plastic condition, and that these have produced, chiefly by
inter-crossing, but likewise by variation, all our existing species.

In 1826 Professor Grant, in the concluding paragraph in his well-known
paper ("Edinburgh Philosophical Journal", vol. XIV, page 283) on the
Spongilla, clearly declares his belief that species are descended
from other species, and that they become improved in the course of
modification. This same view was given in his Fifty-fifth Lecture,
published in the "Lancet" in 1834.

In 1831 Mr. Patrick Matthew published his work on "Naval Timber and
Arboriculture", in which he gives precisely the same view on the origin
of species as that (presently to be alluded to) propounded by Mr.
Wallace and myself in the "Linnean Journal", and as that enlarged in
the present volume. Unfortunately the view was given by Mr. Matthew very
briefly in scattered passages in an appendix to a work on a different
subject, so that it remained unnoticed until Mr. Matthew himself drew
attention to it in the "Gardeners' Chronicle", on April 7, 1860. The
differences of Mr. Matthew's views from mine are not of much importance:
he seems to consider that the world was nearly depopulated at successive
periods, and then restocked; and he gives as an alternative, that new
forms may be generated "without the presence of any mold or germ of
former aggregates." I am not sure that I understand some passages; but
it seems that he attributes much influence to the direct action of
the conditions of life. He clearly saw, however, the full force of the
principle of natural selection.

The celebrated geologist and naturalist, Von Buch, in his excellent
"Description Physique des Isles Canaries" (1836, page 147), clearly
expresses his belief that varieties slowly become changed into permanent
species, which are no longer capable of intercrossing.

Rafinesque, in his "New Flora of North America", published in 1836,
wrote (page 6) as follows: "All species might have been varieties once,
and many varieties are gradually becoming species by assuming constant
and peculiar characters;" but further on (page 18) he adds, "except the
original types or ancestors of the genus."

In 1843-44 Professor Haldeman ("Boston Journal of Nat. Hist. U. States",