can we apply the results of artificial selection to account for the origin of species?

This difficulty is met by Darwin and his followers in this way :-"It is not as yet proved," says Professor Huxley, "that a race ever exhibits, when crossed with another race of the same species, those phenomena of hybridisation which are exhibited by many species when crossed with other species. On the other hand, not only is it not proved that all species give rise to hybrids infertile inter se, but there is much reason to believe that, in crossing, species exhibit every gradation from perfect sterility to perfect fertility." This appears to carry weight; the old theory went with a leap from perfect fertility to perfect sterility, and did not contemplate the possibility of a continuous gradation from the one extreme to the other; at least its argument was founded upon the neglect of such a gradation. But if there be a gradation of this kind, it follows that infertility will merely represent the results of crossing two species whose functional characteristics are very different from each other; and, on the other hand, the reason why artificially produced varieties are not infertile when crossed with one another may only be that the experiment has not been continued long enough.

Time, in fact, is the essential requisite in all such attempts to imitate nature.

172. In connection with this subject, Mr. Darwin has remarked that certain plants are more fertile with the pollen of another species than with their own; and Professor Huxley tells us that there are certain fuci whose male element will fertilise the ovule of a plant of distinct species, while the males of the latter species are ineffective with the females of the first. So obscure in some of its branches is the working of the reproductive system.

Again, the following remark by Mr. Darwin is very suggestive :

"First crosses between forms known to be varieties, or sufficiently alike to be considered as varieties, and their mongrel offspring, are very generally, but not quite universally, fertile. Nor is this nearly general and perfect fertility surprising, when we remember how liable we are to argue in a circle with respect to varieties in a state of nature; and when we remember that the greater number of varieties have been produced under domestication, by the selection of mere external differences, and not of differences in the reproductive system. In all other respects, excluding fertility, there is a close general resemblance between hybrids and mongrels."

173. The result of all these speculations is to render it probable that there may be in nature, give it time enough, a process which leads to the transmutation of species.

The accumulation of successive differences, each representing some element of success in the struggle for life, may easily be imagined in the course of ages to produce a very great change.

Reasoning out this hypothesis, the more advanced followers of Mr. Darwin do not hesitate to ascribe all the varieties of living things, including man, to the result of development from some primordial germ taking place throughout the course of immeasurable ages. And Mr. Darwin himself, in his work on the Descent of Man, lays great stress on the occurrence of homologous structures in man and the lower animals, as well as on the development in man of rudimentary structures, which are either absolutely useless to their possessors, or of very slight service indeed, but which appear to serve as an index of the

various stages through which the human species has passed in its progress upwards from lower forms of life.

174. Mr. Wallace, however, sees in the production of man the intervention of an external will.

He remarks that the lowest types of savages are in possession of a brain, and of capacities far beyond any use to which they could apply them in their present condition, and that therefore they could not have been evolved from the mere necessities of their environments.

175. Finally, Professor Huxley imagines the possibility of the Darwinian hypothesis requiring modification. Alluding to the assumed circularity of the planetary orbits that followed the establishment of the Copernican hypothesis (Art. 69), he remarks :--

"But the planetary orbits turned out to be not quite circular after all, and, grand as was the service Copernicus rendered to science, Kepler and Newton had to come after him. What if the orbit of Darwinism should be a little too circular? What if species should offer residual phenomena, here and there, not explicable by natural selection? Twenty years hence naturalists may be in a position to say whether this is, or is not, the case; but in either event they will owe the author of The Origin of Species' an immense debt of gratitude."

176. We will defer to our last chapter any further remarks on Mr. Darwin's hypothesis. Meanwhile, before concluding, let us briefly allude to the original production of living things on our globe. It may, perhaps, eventually be possible by means of an hypothesis of evolution, to account for the great variety of living forms on the supposition of a single primordial germ to begin with; but the difficulty still remains how to account for this germ.

It is against all true scientific experience that life can appear without the intervention of a living antecedent. How then are we to explain the production of the primordial germ

?

The difficulty of doing so, from our point of view, would appear to be unusually great, for we have come to the conclusion that, as a matter of scientific principle, we cannot admit any such breach of continuity as a pure act of creation in time would imply.

If, then, a pure act of creation in time be an inadmissible hypothesis, and if the hypothesis of Abiogenesis be equally inadmissible, our readers may well ask how are we to surmount the difficulty. For our reply to this question, we must once more beg to refer them to our concluding chapter.

CHAPTER VI.

SPECULATIONS AS TO THE POSSIBILITY OF SUPERIOR INTELLIGENCES IN THE VISIBLE UNIVERSE.

"The earth hath bubbles, as the water has,

And these are of them."-SHAKESPEARE, Macbeth.

177. OUR readers are now aware from what we have said in Chapter II. that the two great requisites for organised existence are, in the first place, an organ of memory, giving the individual a hold upon the past, and secondly, the possibility of varied action in the present, and that unless these two things are fulfilled life is simply inconceivable.

Again, in Chapters III., IV., and v. we have sufficiently discussed the visible universe and its potentialities. We have seen that although at present it contains the essential requisites for organised existence, yet, in the remote future, a time will necessarily arrive when, through a degradation of the Energy of this universe, that variety of motion which is essential to our conception of life will be unattainable. Immortality is, therefore, impossible in such a universe; but even allowing all this to be the case, it is at least conceivable that man may be at death drafted off into some superior rank of being connected with the present universe, and thence ultimately removed into a new order of things when the present universe shall have become effete.

Let us now, therefore, very briefly discuss the question as to the possibility of intelligences superior to man existing