Mesozoic times to the present day, I cannot but put the existence of the common stock from which they sprang far back in the Palæozoic epoch; and I should apply a similar argumentation to all other groups of animals. [The remainder of this essay contains a discussion of questions of taxonomy and phylogeny, which is now antiquated. I have reprinted the considerations about the reconciliation of Teleology with Morphology, about "Dysteleology," and about the struggle for existence within the organism, because it has happened to me to be charged with overlooking them. In discussing Teleology, I ought to have pointed out, as I have done elsewhere (_Life and Letters of Charles Darwin_, vol. ii. p. 202), that Paley "proleptically accepted the modern doctrine of Evolution," (_Natural Theology_, chap. xxiii.). 1893.] V MR. DARWIN'S CRITICS [Footnote: _Contributions to the Theory of Natural Selection_. By A. R. Wallace. 1870.--2. _The Genesis of Species_. By St. George Mivart, F.R.S. Second Edition. 1871.--3. _Darwin's Descent of Man_. Quarterly Review, July 1871.] [1871] The gradual lapse of time has now separated us by more than a decade from the date of the publication of the "Origin of Species"--and whatever may be thought or said about Mr. Darwin's doctrines, or the manner in which he has propounded them, this much is certain, that, in a dozen years, the "Origin of Species" has worked as complete a revolution in biological science as the "Principia" did in astronomy--and it has done so, because, in the words of Helmholtz, it contains "an essentially new creative thought." [Footnote: Helmholtz: _Ueber das Ziel und die Fortschritte der Naturwissenschaft_. Eröffnungsrede für die Naturforscherversammlung zu Innsbruck. 1869.] And as time has slipped by, a happy change has come over Mr. Darwin's critics. The mixture of ignorance and insolence which, at first, characterised a large proportion of the attacks with which he was assailed, is no longer the sad distinction of anti-Darwinian criticism. Instead of abusive nonsense, which merely discredited its writers, we read essays, which are, at worst, more or less intelligent and appreciative; while, sometimes, like that which appeared in the "North British Review" for 1867, they have a real and permanent value. The several publications of Mr. Wallace and Mr. Mivart contain discussions of some of Mr. Darwin's views, which are worthy of particular attention, not only on account of the acknowledged scientific competence of these writers, but because they exhibit an attention to those philosophical questions which underlie all physical science, which is as rare as it is needful. And the same may be said of an article in the "Quarterly Review" for July 1871, the comparison of which with an article in the same Review for July 1860, is perhaps the best evidence which can be brought forward of the change which has taken place in public opinion on "Darwinism."