... agency for the learning of the animals, and for the supplementing of their instincts, is Imitation. The sight of certain movements on the part of the adult animals, or the hearing of their cries, ... by the parents, none of the effects of use or disuse of their limbs, none of the tendencies or habits of action, in short, none of the changes wrought in body or mind of the parents during their ... out of hearing of the peculiar notes of[ 28] their species, they come to make cries of a different sort, or learn to make the notes of some other species with which they are thrown. 4. The...