[74] Phil. Mag. XLVIII, 1899; Collected Papers, IV, p. 430.
[75] Carpenter, The Microscope, edit. 1862, p. 185.
[76] The modern literature on the Brownian Movement is very large, owing to the value which the phenomenon is shewn to have in determining the size of the atom. For a fuller, but still elementary account, see J. Cox, Beyond the Atom, 1913, pp. 118–128; and see, further, Perrin, Les Atomes, pp. 119–189.
[77] Cf. R. Gans, Wie fallen Stäbe und Scheiben in einer reibenden Flüssigkeit? Münchener Bericht, 1911, p. 191; K. Przibram, Ueber die Brown’sche Bewegung nicht kugelförmiger Teilchen, Wiener Ber. 1912, p. 2339.
[78] Ueber die ungeordnete Bewegung niederer Thiere, Pflüger’s Archiv, CLIII, p. 401, 1913.
[79] Sometimes we find one and the same diagram suffice, whether the intervals of time be great or small; and we then invoke “Wolff’s Law,” and assert that the life-history of the individual repeats, or recapitulates, the history of the race.
[80] Our subject is one of Bacon’s “Instances of the Course,” or studies wherein we “measure Nature by periods of Time.” In Bacon’s Catalogue of Particular Histories, one of the odd hundred histories or investigations which he foreshadowed is precisely that which we are engaged on, viz. a “History of the Growth and Increase of the Body, in the whole and in its parts.”
[81] Cf. Aristotle, Phys. vi, 5, 235 a 11, ὲπεὶ γὰρ ἅπασα κίνησις ἐν χρόνῳ, κτλ. Bacon emphasised, in like manner, the fact that “all motion or natural action is performed in time: some more quickly, some more slowly, but all in periods determined and fixed in the nature of things. Even those actions which seem to be performed suddenly, and (as we say) in the twinkling of an eye, are found to admit of degree in respect of duration.” Nov. Org. XLVI.
[82] Cf. (e.g.) Elem. Physiol. ed. 1766, VIII, p. 114, “Ducimur autem ad evolutionem potissimum, quando a perfecto animale retrorsum progredimur, et incrementorum atque mutationum seriem relegimus. Ita inveniemus perfectum illud animal fuisse imperfectius, alterius figurae et fabricae, et denique rude et informe: et tamen idem semper animal sub iis diversis phasibus fuisse, quae absque ullo saltu perpetuos parvosque per gradus cohaereant.”
[83] Beiträge zur Entwickelungsgeschichte des Hühnchens im Ei, p. 40, 1817. Roux ascribes the same views also to Von Baer and to R. H. Lotze (Allg. Physiologie, p. 353, 1851).