Page:Popular Science Monthly Volume 33.djvu/73

Rh of a purely mechanical kind which are conspicuous in organic life, Mr, Spencer has the courage to declare that "no approach" to this kind of fitness "presentable to the senses" is to be found in organisms which continue to live in virtue of special conditions. Where materials are so abundant it is hard to specify. But I am tempted to ask whether Mr. Spencer has ever heard of the ears, the teeth, above all the finger of the aye-aye, the wonderful beast that lives in the forest of Madagascar, and is very nicely fitted indeed to prey upon certain larvæ which burrow up the pith of certain trees? Here we see examples of fitting in a sense as purely mechanical as he could possibly select from human mechanism. The enormous ears are fitted to hear the internal and smothered raspings of the grub. The teeth are fitted for the work of cutting-chisels, while one finger is reduced to the dimension of a mere probe, armed with a hooked claw to extract the larvæ. The fitting of this finger-probe into the pith-tube of the forest bough is precisely like the fitting of a finger into a glove. It is strange indeed that Mr. Spencer should deny the applicability of the word fitness, in its strictest "glove" sense, to adaptations such as these. Yet he does deny it in words emphatic and precise. Neither the organic structures themselves—he proceeds to say—nor their individual movements are related in any analogous way to the things and actions in the midst of which they live. Having made this marvelous denial, he reiterates in another form his great confession—his gran rifiuto—that his own famous phrase, although carefully designed to express self-acting and automatic physical operations, is, after all, a failure. And this result he admits not only as proved, but as obviously true. His confession is a humble one. "Evidently," he says, "the word fittest as thus used is a figure of speech."

This elaborate dissection and condemnation by, Mr. Herbert Spencer of both the two famous phrases which have been so long established in the world as expressing the Darwinian hypothesis—his emphatic rejection of the claim of either of them to represent true physical causation—his sentence upon both of them that they are mere figures of speech—is, in my judgment, a memorable event. As regards Mr. Spencer himself, it is a creditable performance and an honorable admission. It is one of the high prerogatives of the human mind to be able to turn upon its own arguments, and its own imaginings, the great weapon of analysis. There are in all of us, not only two voices, but many voices, and splendid work is done when the higher faculties call upon the lower to give an account of what they have said and argued. Often and often, as the result of such a call, we should