Geoffroy, on his part, exercised some influence on the transcendentalists. He asserts[162] indeed that Spix got some of the ideas published in the Cephalogenesis (1815) from attending his course of lectures in 1809. It is certainly the case that Spix published before Geoffroy the view that the opercular bones are homologous with the ear-ossicles, adopting, however, a different homology for the separate bones.[163]
Some speculations seem to have been common to both schools—for instance, the law of Meckel-Serres, the vertebral theory of the skull, and the recognition of serial homology in the appendages of Arthropods (Savigny, Oken). Latreille and Dugès, as well as Serres, clearly show in their theoretical views the influence of Oken and the other transcendentalists. Geoffroy's principle of connections and law of compensation were recognised by some at least of the Germans.
But whatever his actual historical relations may have been with the German school, Geoffroy was vastly their superior in the matter of pure morphology. He alone brought to clear consciousness the principles on which a pure morphology could be based: the Germans were transcendental philosophers first, and morphologists after.
One understands from this how J. F. Meckel, who was in some ways the leading comparative anatomist in Germany at this time, could be at once a transcendentalist and an opponent of Geoffroy. Meckel had a curiously eclectic mind. A disciple of Cuvier, having studied in 1804-6 the rich collections at the Museum in Paris, the translator of Cuvier's Leçons d'anatomie comparée, he earned for himself the title of the "German Cuvier," partly through the publication of his comprehensive textbook (System der vergl. Anatomie, 5 vols.), partly by his extensive and many-sided research work, partly by his authoritative teaching. His System shows in almost every page of its theoretical part the influence of Cuvier; and it is through having assimilated Cuvier's teaching as to the importance of function that Meckel combats Geoffroy's law of connections, at least in its rigorous form. He submits that the connections of bones and muscles must change in relation to functional requirements. He rejects Geoffroy's theory of the vertebrate nature of Articulates. Generally throughout his work the functional point of view is well to the fore.
Yet at heart Meckel was a transcendentalist of the German school. His vagaries on the subject of "homologues" leave no doubt about that, and, in spite of Cuvier, he believed, though not very firmly, in the existence of one single type of structure.
A Cuverian by training, his lack of morphological sense threw him into the ranks of the transcendentalists, to whom perhaps he belonged by nature.
[141] For a full account, see Kohlbrugge, Zool. Annalen, xxxviii., 1911.
[142] Rede über das Verhältnis der organischen Kräfte, Stuttgart u. Tübingen, 1793 (1814). See Rádl, loc. cit., i., p. 261; ii., p. 57.
[143] Supplem. ad historiam embryonis, Tübingen, 1797.
[144] Lehrbuch der Naturphilosophie, Eng. trans., p. 491, 1847.