'Of the accidental varieties of man, which would occur among the first few and scattered inhabitants of the middle regions of Africa,' he wrote, 'some one would be better fitted than the others to bear the diseases of the country. This race would consequently multiply, while the others would decrease; not only from their inability to sustain the attacks of disease, but from their incapacity of contending with their more vigorous neighbours.... The same disposition to form varieties still existing, a darker and a darker race would in the course of time occur; and as the darkest would be the best fitted for the climate, this would at last become the most prevalent, if not the only race in the country.' Here we have not merely the radical concept of natural selection, but also the subordinate idea of its exertion upon what Darwin calls 'spontaneous variations.' What is wanting in the paper is the application of the faintly descried law to the facts and circumstances of general biology: Wells saw only a particular instance, where Darwin and Wallace more vividly perceived a universal principle. Again, in 1831, Mr. Patrick Matthew in that singular appendix to his book on naval timber actually enunciates the same idea, applied this time to the whole of nature, in words sometimes almost identical with Darwin's own. 'As nature in all her modifications of life,' says this unconscious discoverer, 'has a power of increase far beyond what is needed to supply the place of what falls by Time's decay, those individuals who possess not the requisite strength, swiftness, hardihood, or cunning, fall prematurely without reproducing--either a prey to their natural devourers, or sinking under disease, generally induced by want of nourishment, their place being occupied by the more perfect of their own kind, who are pressing on the means of existence.... The self-regulating adaptive disposition of organised life may, in part, be traced to the extreme fecundity of nature, who, as before stated, has in all the varieties of her offspring a prolific power much beyond (in many cases a thousandfold) what is necessary to fill up the vacancies caused by senile decay. As the field of existence is limited and preoccupied, it is only the hardier, more robust, better-suited-to-circumstance individuals, who are able to struggle forward to maturity, these inhabiting only the situations to which they have superior adaptation and greater power of occupancy than any other kind; the weaker and less circumstance-suited being prematurely destroyed. This principle is in constant action; it regulates the colour, the figure, the capacities, and instincts; those individuals in each species whose colour and covering are best suited to concealment or protection from enemies, or defence from inclemencies and vicissitudes of climate, whose figure is best accommodated to health, strength, defence, and support; whose capacities and instincts can best regulate the physical energies to self-advantage according to circumstances--in such immense waste of primary and youthful life those only come forward to maturity from the strict ordeal by which nature tests their adaptation to her standard of perfection and fitness to continue their kind by reproduction.' Of the ideas expressed in these paragraphs, and others which preceded them, Darwin himself rightly observes, 'He gives precisely the same view on the origin of species as that propounded by Mr. Wallace and myself. He clearly saw the full force of the principle of natural selection.'