[350] System der thierischen Morphologie, p. 5, 1853.
[351] Life and Letters of Charles Darwin, ed. F. Darwin, i., p. 82, 3rd ed., 1887.
[352] The Foundations of the Origin of Species, a Sketch written in 1842. Ed. F. Darwin, Cambridge, 1909.
[353] Cf. a parallel passage in the Origin, 1st ed., pp. 485-6.
[354] In the 1st ed. (p. 439), Darwin makes the curious mistake of attributing this story to Agassiz.
[355] In which nestlings of the different varieties are much more alike than adults. Darwin attached much importance to this idea, see Life and Letters, i., p. 88, and ii., p. 338.
[356] See his Letters, passim.
[357] Writing to Huxley on the subject of the latter's work on the morphology of the Mollusca (1853), he says:—"The discovery of the type or 'idea' (in your sense, for I detest the word as used by Owen, Agassiz & Co.) of each great class, I cannot doubt, is one of the very highest ends of Natural History."—More Letters, ed. F. Darwin and A. C. Seward, 1903, i., p. 73.
[358] Italics mine.
[359] Das Problem des Lebens. Biologische Studien. Bad Sacha, 1906. See also E. Rádl, Biol. Centralblatt, xxi., 1901.