It was an enormous programme, with a Paradisaic freshness. Everything was new and great; and all came from one brain. There was only one man with whom he discussed his ideas as they formed, Carl Gegenbaur, who has undoubtedly had a great, if unconscious, influence on them. Haeckel’s grateful recognition of Gegenbaur’s help in later years was endless and touching. “Thou it was,” he writes to him a little later, “that led me to begin my academic teaching at our beloved Jena six years ago, at the Thuringian university in the heart of Germany, that has, like a beating heart, sent out its living waves of freedom and alertness of mind over Germany for three hundred years. At this nursery of German philosophy and science, under the protection of a free State whose princely rulers ever gave a refuge to free speech and have linked their names for ever with the reform movement, the golden age of German poetry, I was able to work in association with thee. Here we built up our common structure of science in the happiest division of labour, teaching and learning cordially from each other, in the very rooms in which Goethe began his studies of ‘the morphology of organisms’ a half-century before, and partly with the same scientific means, the germs of comparative and philosophic science that he had scattered. We have shared with each other as brothers the happiness and the sorrow that came in the hard struggle for life, and our scientific efforts have been so intimately blended and so mutually helpful, through our daily working and talking together, that it would have been impossible for either of us to determine the particular share of each in our spiritual communism. I can only say in a general way that the little my restless and impulsive youth could offer thee here and there is out of all proportion to the enormous amount I have received from thee, eight years my senior, a more experienced and mature man.” Goethe stood behind the friends as the quiet _genius loci_, giving his blessing to all who worked in his spirit on the old spot. Nor was the place itself without influence. “Much,” Haeckel writes, “may have been even the outcome of the common uplifting enjoyment of nature that was afforded us by the artistic lines of the Jena hills, as they brought before us once more at sunset the magic of the Calabrian mountains by the colour-harmony of their purple and gold banks of cloud and their violet shadows.” “What are the hopes, what are the plans, that man, the creature of a day, builds up?” The words were written by a poet, in his fatal illness, at the spot where the two strong spirits now worked. In the midst of all his hopes and plans Haeckel was struck by a Niobe-shaft. On February 16th, 1864, just on his thirtieth birthday, his wife, only in her twenty-ninth year, in the full force of mind and of love, succumbed to blood-poisoning.