Leopold Jacoby writes thus: “The same year in which appeared Darwin’s book (1859) and coming from a quite different direction, an identical impulse was given to a very important development of social science by a work which long passed unnoticed, and which bore the title: “Critique of Political Economy” by Karl Marx--it was the forerunner of Capital. What Darwin’s book on the “Origin of Species” is on the subject of the genesis and evolution of organic life from non-sentient nature up to Man, the work of Marx is on the subject of the genesis and evolution of association among human beings, of States, and the social forms of humanity.” Commenting on this passage of Jacoby’s Enrico Ferri says: “And this is why Germany, which has been the most fruitful field for the development of the Darwinian theories, is also the most fruitful field for the intelligent, systematic propaganda of socialist ideas. And it is precisely for this reason that in Berlin, in the windows of the book-stores of the socialist propaganda, the works of Charles Darwin occupy the place of honor beside those of Karl Marx.” Frederick Engels, in his reply to Duehring, speaks of Darwin as follows: “He dealt the metaphysical conception of nature the heaviest blow by his proof that all organic beings, plants, animals, and man himself, are the products of a process of evolution going on through millions of years. In this connection Darwin must be named before all others.” Again, in the preface to the “Communist Manifesto” speaking of the materialistic conception of history, he says: “This proposition, in my opinion, is destined to do for history what Darwin’s theory has done for biology.” And speaking at the grave-side of his illustrious colleague--Marx, he said: “Just as Darwin discovered the law of development in organic nature, so Marx discovered the law of development in human society.” Says August Bebel, in “Woman,” “Marx, Darwin, Buckle, have all three, each in his own way, been of the greatest significance for modern development and the future form and growth of human society will, to an extreme degree, be shaped and guided by their teaching and discoveries.” And Kautsky in his work on ethics declares that Darwin’s discoveries “belong to the greatest and most fruitful of the human intellect, and enable us to develop a new critique of knowledge.” Ernest Untermann, in his latest work “Marxian Economics,” well says: “Marx discovered the specific laws of social development among human beings. * * * But while doing this, it never occurred to him to disregard the results of Darwin’s work. On the contrary, he knew the art of combining Darwin’s results with his own, without doing violence to either.”