[43] De generatione animalium, ii. 1; 733ᵅ 6.

[44] Metaphysics, i. 4. De generatione et corruptione, ii. 1.

[45] De anima, ii. 1, ii.

[46] De anima, ii. 2, ii; 413ᵅ 22.

[47] The question of Aristotle’s meaning in connexion with this topic, of primary importance for all thought, has a vast literature. An authoritative work is R. D. Hicks, Aristotle, De anima, Cambridge, 1907.

[48] De partibus animalium, i. 4; 644ᵅ 22.

[49] De partibus animalium, i. 4; 644ᵅ 27.

[50] De partibus animalium, i. 4; 644ᵅ 16.

[51] The classificatory system of Aristotle and its history are discussed in great detail by J. B. Meyer, Aristoteles’ Thierkunde: ein Beitrag zur Geschichte der Zoologie, Physiologie und alten Philosophie, Berlin, 1855.

[52] The work by which Wotton is known is his De differentiis animalium, Paris, 1552.