As to the locality of those scenes, some hints, but scarcely more than hints, can be derived. For in the course of nearly three thousand years, the circumstances of animal distribution have been affected by changes too considerable and too indeterminate to admit of confident argument from the state of things now to the state of things then; while the notices of the poet, incidental by their very nature, are of the utmost value for what they tell, but warrant only very hesitating inferences from what they leave untold. Thus, it does not follow that because Homer nowhere mentions the cuckoo, he was therefore unfamiliar with its note, which, from Hesiod’s time until now, has not failed to proclaim the advent of spring among the olive-groves of Bœotia, and must have been heard no less by Paris or Anchises than by the modern archæological traveller, along the oak-clad and willow-fringed valley of Scamander. Nor is the faintest presumption of a divided authorship supplied by the fact that the nightingale sings in the Odyssey, but not in the Iliad. Nevertheless, analogous considerations should not be altogether neglected in Homeric criticism. They may possibly help towards the answering of questions both of time and place: of time, through allusions to domesticated animals; of place, by a comparison of the known range of wild species with the fauna of the two great epics. And, first, as regards domesticated animals. The list of these is a short one. The Greeks and Trojans of the Iliad commanded the services of the horse in battle, of oxen and mules for draught; dogs were their faithful allies in hunting and cattle driving, and they kept flocks of sheep and goats. The ass appears only once, and then indirectly, on the scene, when the lethargic obstinacy of his behaviour serves to heighten the effect of Ajax’s stubbornness in fight. Thus: And as when a lazy ass going past a field hath the better of the boys with him, an ass that hath had many a cudgel broken about his sides, and he fareth into the deep crop, and wasteth it, while the boys smite him with their cudgels, and feeble is the force of them, but yet with might and main they drive him forth when he hath had his fill of fodder; even so did the high-hearted Trojans and allies, called from many lands, smite great Aias, son of Telamon, with darts on the centre of his shield, and ever followed after him.[136] Footnote 136: _Iliad_, xi. 557-64. The creature’s ‘little ways’ were then already notorious, although all mention of him or them is omitted from the Odyssey, as well as from the Hesiodic poems. His existence is indeed implied by the parentage of the mule. But mules were brought to the Troad _ready-made_ from Paphlagonia.[137] It was not until later that they were systematically bred by the Greeks. Footnote 137: Hehn and Stallybrass, _Wanderings of Plants and Animals_, pp. 110, 460.