[84] Roux, Die Entwickelungsmechanik, p. 99, 1905.
[85] Op. cit. p. 302, “Magnum hoc naturae instrumentum, etiam in corpore animato evolvendo potenter operatur; etc.”
[86] Ibid. p. 306. “Subtiliora ista, et aliquantum hypothesi mista, tamen magnum mihi videntur speciem veri habere.”
[87] Cf. His, On the Principles of Animal Morphology, Proc. R. S. E. XV, 1888, p. 294: “My own attempts to introduce some elementary mechanical or physiological conceptions into embryology have not generally been agreed to by morphologists. To one it seemed ridiculous to speak of the elasticity of the germinal layers; another thought that, by such considerations, we ‘put the cart before the horse’: and one more recent author states, that we have better things to do in embryology than to discuss tensions of germinal layers and similar questions, since all explanations must of necessity be of a phylogenetic nature. This opposition to the application of the fundamental principles of science to embryological questions would scarcely be intelligible had it not a dogmatic background. No other explanation of living forms is allowed than heredity, and any which is founded on another basis must be rejected ....... To think that heredity will build organic beings without mechanical means is a piece of unscientific mysticism.”
[88] Hertwig, O., Zeit und Streitfragen der Biologie, II. 1897.
[89] Cf. Roux, Gesammelte Abhandlungen, II, p. 31, 1895.
[90] Treatise on Comparative Embryology, I, p. 4, 1881.
[91] Cf. Fick, Anal. Anzeiger, XXV, p. 190, 1904.
[92] 1st ed. p. 444; 6th ed. p. 390. The student should not fail to consult the passage in question; for there is always a risk of misunderstanding or misinterpretation when one attempts to epitomise Darwin’s carefully condensed arguments.
[93] “In omni rerum naturalium historia utile est mensuras definiri et numeros,” Haller, Elem. Physiol. II, p. 258, 1760. Cf. Hales, Vegetable Staticks, Introduction.