The Expression of the Emotions in Man and Animals Chapter IV - Means of Expression in Animals Part 1

In which the expressive movements of animals are thoughtfully examined, focusing especially on vocal sounds—whether uttered by the voice or produced by other means—as well as the erection of hairs, feathers, and other appendages in states of anger or terror, all serving to communicate inner sensations and intentions. Through careful observation of diverse species, it is revealed how such natural signs, ranging from cries and growls to the bristling of hair and ruffling of feathers, form a universal language of emotion across the animal kingdom.