Standard accounts of the history of ecology look to Humboldt’s work in botanical or plant geography as one important foundation. Humboldt’s mapping of species (and associations of species) made geography (places) newly important to botany. In comparison to Darwin’s dynamic evolutionary theory--with which it merged in the second half of the 19th century as the story goes--Humboldt’s work is seen as a static taxonomy of species. This account ignores that Humboldt studied in the 1780s with Georg Forster in plant physiology. Humboldt’s vision of nature and of the Cosmos is not static, but physiological! In Cosmos, his last great synthetic work, Humboldt describes the evolution of the Universe, Solar System, and the Earth. In discussing the “universal fluctuation of phenomena,” he believed that “the discovery of every separate law of nature leads the establishment of more general laws.” Citing Carus the celebrated physiologist, Humboldt considered Nature as “that which is ever growing and ever unfolding itself into new forms.” Reflecting on the immense variety of organic forms, he saw in the periodic transformation of animal and vegetable productions, the primordial mystery of all organic development--that same great problem of Metamorphosis.”