If the doctrine of evolution be true--that is to say, if all organic creatures have been developed by ordinary generation from parents--then it follows of necessity that the primæval germs must have contained potentially the whole succeeding series. Moreover, if that series has been developed gradually and very slowly, it follows, also as a matter of necessity, that every modification of structure must have been functionless at first, when it began to appear.... Things cannot be selected until they have first been produced. Nor can any structure be selected by utility in the struggle for existence until it has not only been produced, but has been so far perfected as to actually be used. The Duke proceeds to argue that all adaptive structures must therefore originally have been due to special design: in the earlier stages of their development they must all have been what he calls "prophetic germs." Not yet themselves of any use, and therefore not yet capable of being improved by natural selection, both in their origin and in the first stages (at all events) of their development, they must be regarded as intentionally preparatory to the various uses which they subsequently acquire. Now this argument, forcible as it appears at first sight, is really at fault both in its premiss and in its conclusion. By which I mean that, in the first place the premiss is not true, and, in the next place, that even if it were, the conclusion would not necessarily follow. The premiss is, "that every modification of structure must have been functionless at first, when it began to appear;" and the conclusion is, that, _quâ_ functionless, such a modification cannot have been caused by natural selection. I will consider these two points separately.