There are, however, some who still think that species have suddenly given birth, through quite unexplained means, to new and totally different forms.

But, as I have attempted to show, weighty evidence can be opposed to the admission of great and abrupt modifications.

Under a scientific point of view, and as leading to further investigation, but little advantage is gained by believing that new forms are suddenly developed in an inexplicable manner from old and widely different forms, over the old belief in the creation of species from the dust of the earth.

It may be asked how far I extend the doctrine of the modification of species.