The eyes

also are connected with the brain, and each of them lies at the end of a little vein. Of animals possessed of ears man is the only one that cannot move this organ. Of creatures possessed of hearing, some have ears, whilst others have none, but merely have the passages for ears visible, as, for example, feathered animals or animals coated with horny tessellates. Viviparous animals, with the exception of the seal, the dolphin,
and those others which after a similar fashion to these are cetaceans,
are all provided with ears;