|Goethe's 1784 illustrations of the comparative morphology of an animal and a human, showing that they both possess an intermaxillary bone, and thus both must have morphed (Goethe's term) or evolved (Darwin's term) from a common original form. |
Morphology, said another way, is the study of form similarity, change, and development in animated species.
In 8AD, Roman poet Ovid, published his mythological hexameter poem Metamorphoses; some of which is found in Goethe’s “ECHO cypher” of his Elective Affinities.
In 1784, Goethe initiated the subject of comparative morphology when he discovered the human intermaxillary bone, a bone thought to be unique to lower animals only and not to be found in humans.
This year or thereabouts marks the point when Goethe began serious searching for a scientific principle that could explain the commonality of form change and development across all species of plants, animals, and humans.
In a handwritten note to his Morphology, Goethe defines the subject as follows: 
“Form is a thing in motion, in the process of becoming, of passing away. The study of form is the study of transformation. The study of metamorphosis is the key to all the signs of nature.”
Between 1817 and 1824 Goethe published essays on morphology and general scientific topics in two series. 
In his Zur Morphologie (On Morphology), Goethe declared his preference for the idea of Trieb (drive) as representing the developmental dynamic of living nature, in contrast to Kraft (force), which indicated a material principle that could not explain organization. 
German physician-physicist Hermann Helmholtz, in his essay “On Goethe’s Scientific Researches” (1853), surmised that Goethe’s studies of comparative botany and comparative anatomy led him to “a happy glimpse of an all-pervading law” of the conception that the differences in the anatomy different animals or morphology of different plants are to be “looked upon as variations from a common phase or type, induced by differences of habit, locality, or food.”
American comparative literature scholar Stefani Engelstein (2008), argues that Goethe's "The Metamorphosis of Plants" (1790), "Metamorphosis of Animals" (1806), and Elective Affinities (1809) are to be viewed as a three-part treatise on metamorphology or studies on the similarities of form. 
1. Engelstein, Stefani. (2008). Anxious Anatomy: the Conception of the Human Form in Literary and Naturalist Discourse (§Goethe’s Monstrous Otto, pgs. 26-30; Metamorphology, pgs. 28, 48-54; Elective Affinities or Chosen Correspondences, pgs. 55-60). SUNY Press.
2. Johann Wolfgang von Goethe (biography and complete works) – BooksFactory.com.
3. (a) Goethe, Johann. (date). “Bildungstreib”, Zur Morphologie, in Samtliche Werke, 12:100-2.
(b) Richards, Robert J. (2002). The Romantic Conception of Life: Science and Philosophy in the Age of Goethe (pg. 447-48). University of Chicago Press.
4. (a) Goethe, J. W. v. (1784). Dem Menschen wie den Tieren ist ein Zwischenknochen der odem Kinnlade zuzuschreiben (An Intermaxillary Bone is Present in the Upper Jaw of Man as well as in Animals). Sämtliche Werke 2: 530-545.
(b) From: Goethe, 1784 and 1817; Plate I & Plate IX, original drawing by Waitz.
(c) Filler, Aaron G. (2007). The Upright Ape: A New Origin of the Species (Figure 2-2: Goethe’s Proof of the Human Intermaxillary bone). New Page Books.
5. (a) Goethe, Johann. (date). Publication, in: WA, VI, 293.
(b) Wells, George A. (1967). “Goethe and Evolution” (abs), Journal of the History of Ideas, 28(4):537-50.
● Mayer, Alfred M. (1878). "On the Morphological Laws of the Configurations Formed by Magnets Floating Vertically and Subjected to the Attraction of a Superposed Magnet; with Notes on Some of the Phenomena in Molecular Structure Which These Experiments May Serve to Explain and Illustrate." American Journal of Science, 16: 247-256.
● Iguchi, Nobuhiro and Nishihara, Tadashi. (1996). “Analysis of Environmental Morphologies Using Psychological Entropy.” Department of Mechanical Engineering.
● Morphology (biology) – Wikipedia.