The review containing the above passage did not appear till the present volume was on the very eve of publication. Even a hasty glance at Mr. Mivart’s book is sufficient to show that Mr. Bennett has not over-estimated its importance and value. It is scarcely possible here to do more than make a few reflections upon its general scope, in reply to the challenge offered to Darwinians. The first objection, as it stands in the summary, wears the appearance of a misconception. It is almost certain to produce one. When Mr. Darwin attributes the origin of species to Natural Selection, he includes expressly, and where not expressly, by obvious implication, the principle of Variability. He never maintains that the first or any subsequent stage of a useful structure can be produced by Natural Selection. Natural Selection only operates to preserve. Without Variation it would have no sphere in which to operate, so that from one point of view Mr. Darwin may be said to attribute the origin of species to Variation rather than Natural Selection. He is, moreover, far from ignoring the influence of other principles, such as Inheritance, Reversion, and Correlation, upon the total result. He may be thought inconsistent with himself in laying stress at times upon the minuteness of the variations which he supposes to have slowly accumulated into specific differences, and at other times admitting the sudden appearance of variations which may be considered as large ones, and which are certainly striking. But in the first instance the great and almost overwhelming difficulty was to induce a belief that forms specifically different could be connected with one another by descent. By showing that a multitude of small differences accumulated would make a large total difference, he made as it were a bridge for the existing incredulity. It now appears that the gulf may be passed with easy strides instead of the little slow steps at first thought necessary. This fortifies the doctrine of the Transmutation of Species, in proportion as there are fewer ‘missing links,’ fewer transitional forms that need to be accounted for.