[53] There is a valuable chapter on the subject of the Aristotelian classificatory system as based on the method of reproduction in W. Ogle, Aristotle on the Parts of Animals, London, 1882.
[54] The rediscovery and verification of this and other Aristotelian observations is detailed by C. Singer, ‘Greek Biology and the Rise of Modern Biology,’ Studies in the History and Method of Science, vol. ii, Oxford, 1921.
[55] Historia animalium, ii. 17; 507ᵅ 33.
[56] De partibus animalium, ii. 17; 507ᵇ 12.
[57] Historia animalium, ii. 17; 507ᵇ 12.
[58] Historia animalium, v. 6; 541ᵇ 1. The hectocotylization of the cephalopod arm which is here recorded as an element in the reproductive process of these animals is denied in the De generatione animalium, i. 15; 720ᵇ 32, where we read that ‘the insertion of the arm of the male into the funnel of the female ... is only for the sake of attachment, and it is not an organ useful for generation, for it is outside the passage in the male and indeed outside the body of the male altogether.‘ Yet even here Aristotle knows of the physical relationship of the arm. See note on this point in the translation of the passage by A. Platt, Oxford, 1910.
[59] J. B. Verany, Mollusques méditerranéens, Genoa, 1851.
[60] E. Racovitza. Archives de zoologie experimentale, Paris, 1894.
[61] The paragraphs concerning the fishing-frog and torpedo are made up of sentences rearranged from the De partibus animalium, iv. 13; 696ᵅ 26, and the Historia animalium, ix. 37; 620ᵇ 15.
[62] De partibus animalium, ii. 1; 646ᵅ 12.