[113] Schaper, Arch. f. Entwickelungsmech. XIV, p. 356, 1902. Cf. Barfurth, Versuche über die Verwandlung der Froschlarven, Arch. f. mikr. Anat. XXIX, 1887.
[114] Joh. Schmidt, Contributions to the Life-history of the Eel, Rapports du Conseil Intern. pour l’exploration de la Mer, vol. V, pp. 137–274, Copenhague, 1906.
[115] That the metamorphoses of an insect are but phases in a process of growth, was firstly clearly recognised by Swammerdam, Biblia Naturae, 1737, pp. 6, 579 etc.
[116] From Bose, J. C., Plant Response, London, 1906, p. 417.
[117] This phenomenon, of incrementum inequale, as opposed to incrementum in universum, was most carefully studied by Haller: “Incrementum inequale multis modis fit, ut aliae partes corporis aliis celerius increscant. Diximus hepar minus fieri, majorem pulmonem, minimum thymum, etc.” (Elem. VIII (2), p. 34).
[118] See (inter alia) Fischel, A., Variabilität und Wachsthum des embryonalen Körpers, Morphol. Jahrb. XXIV, pp. 369–404, 1896. Oppel, Vergleichung des Entwickelungsgrades der Organe zu verschiedenen Entwickelungszeiten bei Wirbelthieren, Jena, 1891. Faucon, A., Pesées et Mensurations fœtales à différents âges de la grossesse. (Thèse.) Paris, 1897. Loisel, G., Croissance comparée en poids et en longueur des fœtus mâle et femelle dans l’espèce humaine, C. R. Soc. de Biologie, Paris, 1903. Jackson, C. M., Pre-natal growth of the human body and the relative growth of the various organs and parts, Am. J. of Anat. IX, 1909; Post-natal growth and variability of the body and of the various organs in the albino rat, ibid. XV, 1913.
[119] l.c. p. 1542.
[120] Variation and Correlation in Brain-weight, Biometrika, IV, pp. 13–104, 1905.
[121] Die Säugethiere, p. 117.
[122] Amer. J. of Anatomy, VIII, pp. 319–353, 1908. Donaldson (Journ. Comp. Neur. and Psychol. XVIII, pp. 345–392, 1908) also gives a logarithmic formula for brain-weight (y) as compared with body-weight (x), which in the case of the white rat is y = ·554 − ·569 log(x − 8·7), and the agreement is very close. But the formula is admittedly empirical and as Raymond Pearl says (Amer. Nat. 1909, p. 303), “no ulterior biological significance is to be attached to it.”