All such difficulties are enormously aggravated by a consideration which, obvious as it is, seems seldom to be considered. The arguments we commonly hear appear to imply that _one_ parent is sufficient to secure the transmission of a beneficial variation to the next generation. But, of course, the parent requires a mate, and unless this mate has chanced to hit on the same line of variation, it cannot be supposed that it will be transmitted. Seeing, however, the exceeding minuteness of these variations in each instance, they can avail nothing to bring together the right mates to perpetuate them. Two reptiles, for instance, are not the more likely to pair because their fore limbs have taken the first faint and distant step towards becoming wings, while in the vegetable kingdom, notwithstanding Erasmus Darwin's _Loves of the Plants_, the idea of any choice of partners is still more grotesque. The allotment of mates must therefore be left to Chance; and the results will follow the ordinary laws of probability. Accordingly, if we suppose so large a proportion as five per cent., or one in twenty, of any species to possess an advantageous variation,--only one in twenty of the individuals thus favoured will secure a similarly favoured mate,--for each will have nineteen wrong selections offered to him or her, for one right one. Only one pair in four hundred will therefore transmit the variation to five per cent. of _their_ offspring, or one in eight thousand of the species, and of these only one pair in a-hundred-and-sixty-thousand will make an advantageous match. Such is the inevitable consequence of leaving any definite result to Chance: and here it is that Natural Selection is found to betray the most fatal of all its deficiencies; for, whatever its advocates may say, it is Chance and Chance alone upon which it relies. Just because man can and does select the proper mates, is he able to produce by breeding the results to which Mr. Darwin appeals as evidence, that Nature having no such power of selection, must be able to produce results of which man cannot even dream.[201] Natural Selection is in truth no selection at all, that is just its weak point, which the title conferred upon it serves to hide. What are called its products owe no more to it than Wellington owed his generalship to the bullets which did not hit him at Seringapatam. If they are not determined to a particular development they can attain it only by Chance.