It will be readily admitted that of all living writers Mr. Alfred Russel Wallace is the one the peculiar turn of whose mind best fits him to write on the subject of natural selection, or the accumulation of fortunate but accidental variations through descent and the struggle for existence. His mind in all its more essential characteristics closely resembles that of the late Mr. Charles Darwin himself, and it is no doubt due to this fact that he and Mr. Darwin elaborated their famous theory at the same time, and independently of one another. I shall have occasion in the course of the following article to show how misled and misleading both these distinguished men have been, in spite of their unquestionable familiarity with the whole range of animal and vegetable phenomena. I believe it will be more respectful to both of them to do this in the most out-spoken way. I believe their work to have been as mischievous as it has been valuable, and as valuable as it has been mischievous; and higher, whether praise or blame, I know not how to give. Nevertheless I would in the outset, and with the utmost sincerity, admit concerning Messrs. Wallace and Darwin that neither can be held as the more profound and conscientious thinker; neither can be put forward as the more ready to acknowledge obligation to the great writers on evolution who had preceded him, or to place his own developments in closer and more conspicuous historical connection with earlier thought upon the subject; neither is the more ready to welcome criticism and to state his opponent's case in the most pointed and telling way in which it can be put; neither is the more quick to encourage new truth; neither is the more genial, generous adversary, or has the profounder horror of anything even approaching literary or scientific want of candour; both display the same inimitable power of putting their opinions forward in the way that shall best ensure their acceptance; both are equally unrivalled in the tact that tells them when silence will be golden, and when on the other hand a whole volume of facts may be advantageously brought forward. Less than the foregoing tribute both to Messrs. Darwin and Wallace I will not, and more I cannot pay.