never made a journey to see them, while they were trampled under foot every day by the visitors bathing in Heligoland. They must move. It was not necessary to go round the world: a holiday journey to the North Sea or the Mediterranean would suffice. Every cultured man had always considered that he must make at least one pilgrimage to classic lands before his education was complete. It was only a question of changing material. They were not to confine themselves to examining ruined temples and aqueducts, but to take their microscopes down to the coast, draw a bucketful of sea-water, and examine its living contents—the living medusa and sea-urchin, and the living world of the swarming infusoria. But it was like the rending of the great curtain of the temple. Zoology seemed to expand ten-fold, a hundred-fold, in a moment. A room in an obscure inn by the sea, a microscope, and a couple of glasses of salt-water with sediment every morning—and the finest studies at Paris and London were as ploughed land, without a single blade, in face of this revelation. It was a Noah’s ark in the space of a pinch of snuff. One day the young medical student heard, in the middle of his histology and zoology, that Kölliker had come back from Messina. He had been studying lower marine life there. In 1853, two young men were together in the Gutenberg forest near Würtzburg. One of them, Karl Gegenbaur, had been abroad with Kölliker. With his impressions still fresh, he tells Haeckel about his zoological adventures in the land of the Cyclops. Gegenbaur, eight years older than Haeckel, was by birth and education a typical Würtzburger. He, too, had studied medicine, and had practised at the hospital. But he had already advanced beyond that. His stay at Messina had been devoted entirely to zoological purposes. A year later he would be teaching anatomy at Würtzburg, and a year later still he would be called to Jena. From that time he began to be known as a master of comparative anatomy—especially after 1859, when his _Elements_ of the science was published, a classic in its way that still exercises some influence.