turbed by two different structures and constitutions having been blended in one (288).

And with these verbal solemnities, which add nothing to the stock of our information, Mr Darwin concludes in the passage which we have already seen: 'It must be confessed that we do not understand, except on vague hypotheses, several facts with respect to the sterility of hybrids '---' nor do I,' says he, 'pretend that the foregoing remarks go to the root of the matter: NO EXPLANATION IS OFFERED WHY AN ORGANISM, WHEN PLACED UNDER UNNATURAL CONDITIONS, IS RENDERED STERILE' (288).

Surely after this most ample confession, Mr Darwin might have spared himself the pains of composing half a dozen pages of learned talk, all ending in the very point from which he had started, without advancing a hair's breadth towards an explanation of the mystery. We have no difficulty, then, in concluding that the law of sterility, with its singular rules,' is something beyond even Mr Darwin's reasoning powers. If we have slurred over this enigma, he, by his expansion, has largely exhibited his ignorance, and made it quite manifest that he is no more able to explain the subject than we who acknowledge our ignorance, and do not conceal that it is beyond our reasoning powers.

CHAPTER IV.

NATURAL SELECTION.

HAVING thus gone through the question of species as we have seen it stated, we now come to the fundamental principle of the whole theory, Natural Selection, which it has become necessary occasionally to anticipate, as it is mixed up with Mr Darwin's statements and reasonings in every chapter of his book. It is now proposed to show at some length what the author means by Natural Selection, adducing his own words for authentic information.

In the general explanation of Natural Selection we may say, that it means that when plants or animals have been in circumstances wherein some modification of their existing organization would be for their benefit, the change has been effected by very slow degrees, gradually and imperceptibly advancing towards the beneficial point; and the changes, however minute, accumulating, in the long-protracted process of geological time, new forms of the animal or plant have at last been elaborated. It is not, however, to be supposed that these mutations have effected a permanent state of things, for though certain divisions of the families of animals and plants have thus been brought into existence, so as to be recognized as genera, and 'good and distinct species,' yet this is only temporary, for all varieties

are to be considered as incipient species, and species itself differs not essentially or fundamentally from variety. All nature, then, is on the move; that which we call Creation is not effected and finished, but is working onwards to a finish, when all beings that have life will be in a state of perfection, and there will be no more change.

This, however, must be seen in the author's own words: The preservation of favourable variations and the rejection of injurious variations I call Natural Selection' (84). 'Nature grants vast periods of time for the work of Natural Selection' (107). No complex instinct can be produced through Natural Selection, except by slow and gradual accumulation of numerous slight but profitable variations' (260). 'The chief cause of our natural unwillingness to admit that one species has given birth to another and distinct species is, that we are always slow in admitting any great change of which we have not seen the intermediate steps. The mind cannot possibly grasp the full meaning of a hundred million of years. It cannot add up and perceive the full effects of many slight variations, accumulated during almost an infinite series of generations' (516). By the theory of Natural Selection all living species have been connected with the parent species of each genus, by differences not greater than we see between the varieties of the same species in the present day; and these parent species, generally extinct, have in their turn been similarly connected' with more ancient species, and so on, backwards, always converging to the common ancestor of each great class-so that the number of intermediate and transitional links between all living and extinct species must have been incomparably great: but assuredly, IF THIS THEORY BE TRUE, such have lived upon earth' (305). 'I see no difficulty, under

changing conditions of life, in Natural Selection accumulating slight modifications of instinct to any extent in any useful direction' (265). Natural Selection, on the principle of qualities being inherited at corresponding ages, can modify the eggs, seed, or young as easily as the adult' (144). On the principle of Natural Selection, with divergence of character, it does not seem incredible that from some such low and intermediate form (the lower alga) both animals and plants may have been developed; and if we admit this, we must admit that all the organic beings which have ever lived on the earth may have descended from some one primordial form' (519). The ultimate result will be that each creature will tend to become more and more improved in relation to its condition of life. This improvement will, I think, inevitably lead to the gradual advancement of the organization of the greater number of living beings throughout the world' (133).

This is the creed in the authentic words of the inventor of the theory. It is but fair, however, to add a corollary of the whole: If Natural Selection be a true principle, it will banish the belief of the continued creation of new organic beings, or of any great and sudden modification of their structure' (101). In other words, if Mr Darwin's theory be true, we have done with the Creator. Creation disappears as an obsolete idea, and Natural Selection takes its place.

Natural Selection has another principle to aid its operations, the Struggle for Life,' a competition for existence, by which the weak have to make way for the strong; so that those animals and vegetables which can make most of their opportunities, and most improve their qualities, are sure to supersede their less fortunate or less provident rivals. The

unimproved become extinct, whilst the accumulators of useful varieties remain masters of the field.

On this Mr Darwin has much to say. How do these groups of species, which constitute what are called distinct genera, and which differ from each other more than do the species of the same genus, arise? All these results follow from the struggle for life. Owing to this struggle for life, any variation, however slight, and from whatever cause proceeding, if it be in any degree profitable to an individual of any species, in its infinitely complex relations to other organic beings, and to its physical condition of life, will tend to the preservation of that individual, and will generally be inherited by its offspring' (64). I use the term struggle for existence in a large and metaphorical sense, including dependence of one being on another, and including (which is most important) not only life of the individual, but success in bearing progeny' (166). In looking at Nature it is most necessary never to forget that every single organic being around us may be said to be striving to the utmost to increase in number; that each lives by a struggle at some period of its life; that heavy destruction inevitably falls either on the young or the old, during each generation or at recurrent intervals. Lighten any check, mitigate the destruction ever so little, and the number of the species will almost instantaneously increase to any amount' (69).

With these quotations we have enough before us to comprehend the author's theory. We must now endeavour to ascertain what may be the precise meaning of the term 'Natural Selection,' which in itself contains substantially the whole of Mr Darwin's theory. An unknown power selects and makes choice; it adopts, repudiates, modifies, and changes certain qualities in animals and vegetables; it