a1 Corpus Christi College, Cambridge
I start with two contradictory statements: (1) Jaeger, Aristotle (Eng. trans.), p. 330: ‘Thus all indications point to a late date for the origin of the philosopher's zoological works.’ (2) D'Arcy Thompson, Historia Animalium (Oxford Translation), Prefatory Note: ‘It can be shown that Aristotle's natural history studies were carried on, or mainly carried on, in his middle age, between his two periods of residence at Athens.‘
1 This paper was originally read to the Cambridge Philological Society in November 1946. I am grateful to Professor Hackforth for reading it in draft and for his suggestions.