But Duges' main contribution to morphological method was his conception of the living organism as a colony of lesser units, which were themselves real "organisms." "By _organism_ the author means a complex of organs which taken together suffice to constitute, ideally or actually, a complete animal. An 'organism' is, as it were, an elementary or simple animal; several organisms combined form a complex animal" (p. 255). Duges hit upon this principle, which was first suggested to him by A. Moquin-Tandon's work on the leech (1827), as a great aid in demonstrating the unity of plan and composition throughout the animal kingdom.[140] According to his view there are three main types of animals--(1) Biserials, including bilaterally symmetrical animals, composed of two parallel series of "organisms"; (2) Radiates, composed of "organisms" arranged like the spokes of a wheel; and (3) Raceme-animals, in which the separate "organisms" were disposed more or less irregularly, in bunches (p. 257). The unitary "organism" is supposed to be the same in all, only the arrangement differing. Duges of course admitted that the centralisation of the complete organism became greater the higher it stood in the scale, and that this held good also in individual development. The appendages of Articulates and Vertebrates were thought of as the members of as many separate organisms. He went so far as to suggest that the fingers of a man's hand were the free extremities of as many thoracic members. Duges' conception of the organism has often been revived since in a saner form, _e.g._, by E. Perrier, and it has a certain validity. It has much affinity with the similar conceptions of Goethe and the German transcendentalists. [130] _Mem. Acad. Sci._, iv., pp. cclxxxiv.-ccci., 1824. [131] _Ann. Sci. Nat._, xi., xii., 1827; xvi., 1829; xxi., 1830. [132] See Radl, _loc. cit._, i., pp. 225-6. [133] _Ann. Sci. nat._ (2), ii., p. 248, 1834. [134] _Ann. Sci. nat._, iii., pp. 377-80, 1824. [135] _Memoires sur les Animaux sans Vertebres_, Part I., p. 10, Paris, 1816. [136] _Ann. Sci. Nat._, (1), i., pp. 97-135, 416-432, 1824. [137] _Isis_, p. 456, 1820 (2). [138] Cuvier, _Mem. Acad. Sci._, iv., p. cclxx., 1824. [139] _Acad. Sci._ 18th Oct. 1831. Extract in _Ann. Sci. Nat._, xxiv., pp. 254-60, 1831. [140] His views were more fully elaborated in his _Memoire sur la conformite organique dans l'echelle animale_, Montpellier, 1832. CHAPTER VII THE GERMAN TRANSCENDENTALISTS