Darwin always looked back on this first conflict of his ideas in presence of the dead shells and bones of the ancient pampas animals as an hour of awakening. It was the birth of his humanity in the higher sense. It is of interest to us because it coincides exactly with the date of Haeckel’s birth in the ordinary sense. In Darwin’s fine account of his voyage, which is mostly arranged in the form of a diary, we find a passage written on the east coast of Patagonia on January 9, 1834, and the next on April 13th. In the meantime the ship had made a short zigzag course, which is spoken of in another connection. But the interval between the two dates is taken up with a passage on these gigantic animals, the reasons for their extinction and the striking fact of their bodily resemblance to the living animals of South America. “This remarkable resemblance,” we read, “between the dead and the living animals of one and the same continent will yet, I doubt not, throw more light on the appearance of organic beings on the earth than any other class of facts.” This is clearly a summary of Darwin’s deepest thoughts at the time. Haeckel was born on February 16th of the same year, 1834. Thus the bodily birth of one of the two men whom we conceive to-day as Dioscuri coincides with the spiritual rebirth of the other. But it would be nearly thirty years before they would meet in spirit never to part again. At the very beginning of their acquaintance Darwin wrote a letter to Haeckel (October 8, 1864) in which he speaks of the earliest suggestions of his theory. The Hamlet-hour comes back vividly to his memory. “I shall never forget my astonishment when I dug out a gigantic piece of armour, like that of a living armadillo. As I reflected on these facts and compared others of a like nature, it seemed to me probable that closely related species may have descended from a common ancestor.” However we take it, Darwin then saw for the first time that his difficulty about the mutability of species was from the first, in his own mind, a difficulty about God. He began his doubts with the ancient armadillo; he ended with God.