Who shall decide between such extreme views so ably maintained on either hand, and say how much of truth there may be in each?  The present reviewer has not the presumption to undertake such a task.  Having no prepossession in favor of naturalistic theories, but struck with the eminent ability of Mr. Darwin’s work, and charmed with its fairness, our humbler duty will be performed if, laying aside prejudice as much as we can, we shall succeed in giving a fair account of its method and argument, offering by the way a few suggestions, such as might occur to any naturalist of an inquiring mind.  An editorial character for this article must in justice be disclaimed.  The plural pronoun is employed not to give editorial weight, but to avoid even the appearance of egotism, and also the circumlocution which attends a rigorous adherence to the impersonal style.

We have contrasted these two extremely divergent theories, in their broad statements.  It must not be inferred that they have no points nor ultimate results in common.

In the first place, they practically agree in upsetting, each in its own way, the generally-received definition of species, and in sweeping away the ground of their objective existence in Nature.  The orthodox conception of species is that of lineal descent:  all the descendants of a common parent, and no other, constitute a species; they have a certain identity because of their descent, by which they are supposed to be recognizable.  So naturalists had a distinct idea of what they meant by the term species, and a practical rule, which was hardly the less useful because difficult to apply in many cases, and because its application was indirect:  that is, the community of origin had to be inferred from the likeness; such degree of similarity, and such only, being held to be con-specific as could be shown or reasonably inferred to be compatible with a common origin.  And the usual concurrence of the whole body of naturalists (having the same data before them) as to what forms are species attests the value of the rule, and also indicates some real foundation for it in Nature.  But if species were created in numberless individuals over broad spaces of territory, these individuals are connected only in idea, and species differ from varieties on the one hand, and from genera, tribes, etc., on the other, only in degree; and no obvious natural reason remains for fixing upon this or that degree as specific, at least no natural standard, by which the opinions of different naturalists may be correlated.  Species upon this view are enduring, but subjective and ideal.  Any three or more of the human races, for example, are species or not species, according to the bent of the naturalist’s mind.  Darwin’s theory brings us the other way to the same result.  In his view, not only all the individuals of a species are descendants of a common parent, but of all the related species also.  Affinity, relationship, all the terms which naturalists use figuratively to