On the 18th of September, 1877, Ernest Haeckel, the celebrated embryologist of Jena, delivered at the Congress of Naturalists, which was held at Munich, an eloquent address defending and propagating Darwinism, which was at that time the object of the most bitter polemical attacks. A few days afterward, Virchow, the great pathologist, an active member of the "progressive" parliamentary party, hating new theories in politics just as much as in science-violently assailed the Darwinian theory of organic evolution, and, moved by a very just presentiment, hurled against it this cry of alarm, this political anathema: "Darwinism leads directly to socialism". The German Darwinians, and at their head Messrs. Oscar Schmidt and Haeckel, immediately protested and in order to avert the addition of strong political opposition to the religious, philosophical, and biological opposition already made to Darwinism, they maintained, on the contrary, that the Darwinian theory is in direct, open and absolute opposition to socialism.