Page:Encyclopædia Britannica, Ninth Edition, v. 16.djvu/871

Rh MORPHOLOGY 839 The histological movement inaugurated by Bichat will be subsequently discussed ; the rise of embryology, how ever, may be briefly noted, especially since it supplied the most obvious deficiency of the Cuvierian school. Here the principal figure is Von Baer, who established independently the four types of Cuvier on developmental grounds, so for the first time applying embryology as the touchstone of anatomical classifications, besides establishing his famous law of differentiation from a general towards a special form. It is now necessary to return to Linnaeus, whose more speculative writings contain, though encumbered by fan tastic hypotheses, the idea of floral metamorphosis (&quot; Prin- cipium florum et foliorum idem est,&quot; &c.). About the same time, and quite independently, C. F. Wolff, the embryo- logist, stated the same theory with greater clearness, for the first time distinctly reducing the plant to an axis bearing appendages the vegetative leaves which become meta morphosed into bud-scales or floral parts through diminu tion of vegetative force. Thirty years later the same view was again independently developed by Goethe in his now well - known pamphlet ( Versuch die Metamorphose der Pjlanzen zu erklaren, Gotha, 1790). In this brilliant essay the doctrine of the fundamental unity of floral and foliar parts is clearly enunciated, and supported by arguments from anatomy, development, and teratology. All the organs of a plant are thus modifications of one funda mental organ the leaf and all plants are in like manner to be viewed as modifications of a common type the Urpflanze. The controversy as to the merits and import ance of this essay, and of Goethe s morphological work in general, can scarcely be entered upon here. That Goethe discerned and proclaimed, and that more clearly than any of his predecessors or contemporaries, the fundamental idea of all morphology the unity which underlies the multi farious varieties of organic form and that he systematically applied this idea to the interpretation of the most import- .ant, most complex, and most varied animal and vegetable structures, is unquestionable. The difficulties arise when we .seek to estimate the importance of his works in the chain of progress, and when we inquire whether, as some historians hold, his &quot; urpflanze &quot; was a mere ideal archetype, bringing forth as its fruit the innumerable metaphysical abstractions of the Naturphilosophie, and leading his countrymen, to their fall, into all the extravagances of that system ; or whether, as Haeckel maintains, it represented a concrete an- cestral form, so anticipating the view of modern evolutionists. That to him Schelling was largely indebted for the founda tion upon which he erected his philosophic edifice, as also that Goethe largely shared the same ideas, is unquestion able ; but it must be remembered that he lived and made progress for forty years after the publication of this essay, that he was familiar with the whole scientific movement, Lamarck and Geoffrey St-Hilaire ; it is not therefore to be wondered at that his writings should furnish evidence in favour of each and every interpretation of them. His other morphological labours must not be forgotten. Inde pendently of Vicq d Azyr, he discovered the human pre- maxillary bone ; independently of Oken, he proposed the vertebral theory of the skull ; and before Savigny, he dis cerned that the jaws of insects were the limbs of the head. In 1813 A. P. de Candolle published his Theorie le- mentaire de la Botanique, which he developed into the classic Organographie Vegetale (1827). Although at first unac quainted with Goethe s essay, and not clearly discerning the homology of leaves and floral parts, he established his theory of symmetry, reducing all flowers to &quot;symmetrical&quot; groupings of appendages on an axis and accounting for their various forms by cohesion and adhesion, by arrested or excessive development. The next great advance was the investigation by Schimper and Braun of phyllotaxis the ascending spiral arrangement of foliar and floral organs thus further demonstrating their essential unity. The term morphology was first introduced by Goethe in 1817, in a subsequent essay (Zur Natunvissenschaft uberhaupt, besonders zur Morpkologie}. It did not come into use in botany until its popularization by Auguste de St-Hilaire in his admirable Morphologic Vegetale (1841), and in zoology until later, although De Blainville, who also first employed the term type, had treated the external forms of animals under &quot; morphologic.&quot; Though the Na- turphilosophie of Schelling and its countless modifications by his followers, its mystic theories of &quot; polarization &quot; and the like, its apparatus of assumption and abstraction, hy pothesis and metaphor, cannot here be discussed, its un doubted services must not be forgotten, since it not only stimulated innumerable reflective minds to the earnest study of natural science, but, by its incessant proclamation of the unity of nature and the free use of Platonic arche types, gave a most powerful impulse to the study of com parative anatomy, and nobly vindicated the claims of philo sophic synthesis over those of merely analytic empiricism. Among its many adherents, some are of more distinctly theological type, others metaphysical, others mystical or poetic, others, again, more especially scientific ; but its most typical and picturesque figure is Lorenz Oken, who epitomizes alike the best and the worst features of the school, and among whose innumerable pseudo- morpholo gical dreams there occasionally occurred suggestions of the greatest fruitfulness, notably, for instance, the independ ent statement of the vertebral theory of the skull. Although Lamarck shared in this movement, his great work (the Philosophic Zoologique, 1809), being setiolo- gical rather than morphological, scarcely claims discussion here. By far the most distinguished anatomist of the transcendental school is Geoffroy St-Hilaire, who being comparatively free from the extravagances of Oken, and uniting a depth of morphological insight scarcely inferior to that of Goethe with greater knowledge of facts and far wider influence and reputation in the scientific world (which affected to sneer at the poet as necessarily a mere amateur), had enormously greater influence on the progress of science than either. He started from the same studies of anatomi cal detail as Cuvier, but, profoundly influenced by Buffon s view of unity of plan and by the evolutionary doctrines of Lamarck, he rapidly diverged into new lines, and again reached that idea of serial homology of which we have so frequently noted the independent origin. His greatest work, the Philosophic Anatomique (1818-1823), contains his principal doctrines. These are (1) the theory of unity of organic composition, identical in spirit with that of Goethe ; (2) the theory of analogues, according to which the same parts, differing only in form and in degree of development, should occur in all animals; (3) the &quot;principe des con nexions,&quot; by which similar parts occur everywhere in similar relative positions ; and (4) the &quot; principe du balancement des organes,&quot; upon which he founded the study of tera tology, and according to which the high development of one organ is allied to diminution of another. The advance in morphological theory is here obvious ; unfortunately, how ever, in eager pursuit of often deceptive homologies, he wandered into the transcendentalism of the Naturphilo- sophie, and seems utterly to have failed to appreciate either the type theory of Cuvier or the discoveries of Von Baer. He earnestly defended Buffon s and Bonnet s earlier view of unity of plan in nature ; and the controversy reached its climax in 1830, when he maintained the unity of structure in Cephalopoda and Vertebrates against Cuvier before the Academy of Sciences. On the point of fact he was of course utterly defeated ; the type theory was
 * and warmly sympathized with the evolutionary views of