But these better motions remained without importance for the history of botany; the adherents of his doctrine of metamorphosis all apprehended it in the sense of the nature-philosophy, and Goethe himself did not remonstrate against the frightful way in which it was distorted by them. Its further development therefore was in accordance with the principles of that philosophy, which was accustomed to apply the results of purely idealistic views in an uncritical way to imperfectly observed facts. Above all the difficulty remained unsolved, how the dogma of the constancy of species was to be brought into logical connection with the idea of the metamorphosis of organs. The supranatural, which Elias Fries found in the natural system, subsisted still in the doctrine of metamorphosis in comparing the organs of a plant. Still more obscure and entirely the product of the nature-philosophy is Goethe’s view of the spiral tendency in vegetation. At p. 194 of his essay entitled ‘Spiraltendenz der Vegetation’ (1831) he says: ‘Having fully grasped the idea of metamorphosis we next turn our attention to the vertical tendency, in order to gain a nearer acquaintance with the development of the plant. This tendency must be looked upon as an immaterial staff, which supports the existence.... This principle of life (!) manifests itself in the longitudinal fibres which we use as flexible threads for many purposes; it is this which forms the wood in trees, which keeps annual and biennial plants erect, and even produces the extension from node to node in climbing and creeping plants. Next we have to observe the spiral direction which winds round the other.’ This spiral direction which passes at once with Goethe into a ‘spiral tendency,’ is seen in various phenomena of vegetation, as in spiral vessels, in twining stems, and sometimes in the position of leaves. The closing remarks of this short essay, in which he explains the vertical tendency as the male, the spiral as the female principle in the plant, show how far Goethe lost himself in the profundities of the nature-philosophy. Thus he introduced his readers into the deepest depths of mysticism.