Mr. Darwin's hypothesis is not, so far as I am aware, inconsistent with any biological fact; on the contrary, if admitted, the facts of Development, of Comparative Anatomy, of Geographical Distribution, and of Palæontology, become connected together, and exhibit a meaning such as they never possessed before; and I, for one, am firmly convinced, that if not precisely true, that hypothesis is as near an approximation to the truth as, for example, the Copernican hypothesis was to the true theory of the planetary motions. But for all this, our acceptance of the Darwinian hypothesis must be provisional so long as one link in the chain of evidence is wanting; and so long as all the animals and plants certainly produced by selective breeding from a common stock are fertile with one another, the link will be wanting. For, so long, selective breeding will not be proved to be competent to do all that is required of it to produce natural species. This missing link, like various others, has never been supplied, and in consequence Professor Huxley never abandoned his attitude of reserve. On the contrary, when, in 1880, he delivered an address to celebrate "the Coming of Age of the _Origin of Species_" he discharged the task without once mentioning Natural Selection, which is to that work as the Prince of Denmark is to _Hamlet_. But there is one passage in the said address, which deserves to be specially remembered: History warns us that it is the customary fate of new truths to begin as heresies and to end as superstitions; and, as matters now stand, it is hardly rash to anticipate that, in another twenty years, the new generation, educated under the influences of the present day, will be in danger of accepting the main doctrines of the _Origin of Species_, with as little reflection, and it may be with as little justification, as so many of our contemporaries, twenty years ago, rejected them. In 1886, Professor Romanes pronounced as follows:[236] "At present it would be impossible to find any working naturalist who supposes that survival of the fittest is competent to explain all the phenomena of species-formation." As to the actual position now occupied in Scientific opinion by Mr. Darwin's hypotheses, we may content ourselves with the declaration of Professor S. H. Vines in his Presidential address to the Linnean Society, May 24, 1902. 1. It is established that Natural Selection, though it may have perpetuated species, cannot have originated any. 2. It is still a mystery why Evolution should tend from the lower to the higher, from simple to complex organisms. 3. The facts seem to admit of no other interpretation than that variation is not [as Darwin supposed] indeterminate, but that there is in living matter an inherent determination in favour of variation in the higher direction.