This verbal association has no doubt had the effect of still further preserving the traditional halo of mystery which clings to the idea of a "species." Hence it comes that the title which Darwin chose--and, looking to the circumstances of the time, wisely chose--for his great work, has subsequently had the effect of fostering the very idea which it was the object of that work to dissipate, namely, that species are peculiar entities, which differ more or less in origin or kind from all other taxonomic groups. The full title of this work is--_The Origin of Species by means of Natural Selection: or the Preservation of Favoured Races in the Struggle for Life_. Now, supposing that instead of this its author had chosen some such title as the following:--_The Origin of Organic Types by means of Adaptive Evolution: or Survival of the Fittest Forms in the Struggle for Life_. Of course this would have been a bad substitute from various points of view; but could any objection have been urged against it from our present point of view? I do not see that there could. Yet, if such had been the title, I have little doubt that we should never have heard of those great generalizations with regard to species and specific characters, the futility of which it has been the object of these chapters to expose. * * * * * In conclusion, it only remains to reiterate that in thus combating what appears to me plainly erroneous deductions from the theory of natural selection, I am in no wise combating that theory itself. On the contrary, I hope that I am rendering it no unimportant service by endeavouring to relieve it of a parasitic growth--an accretion of false logic. Regarding as I do the theory of natural selection as, primarily, a theory of the origin (or cumulative development) of adaptations, I see in merely non-adaptive characters--be they "specific" or other--a comparatively insignificant class of phenomena, which may be due to a great variety of incidental causes, without any further reference to the master-principle of natural selection than that in the presence of this principle none of these non-adaptive characters can be actively deleterious. But that there may be "any number of indifferent characters" it is no part of the theory of natural selection to deny; and all attempts to foist upon it _a priori_ "deductions" opposed alike to the facts of nature and to the logic of the case, can only act to the detriment of the great generalization which was expressly guarded from such fallacies by the ever-careful judgement of Darwin. APPENDICES AND NOTES APPENDIX I. ON PANMIXIA.