Note 427 — Chapter XXV · [395]

Loc. cit. § 497. Why a dog's face-muscles are not more mobile than they are Mr. Spencer fails to explain, as also why different stimuli should innervate these small muscles in such different ways, if easy drainage be the only principle involved. Charles Bell accounted for the special part played by the facial muscles in expression by their being accessory muscles of respiration, governed by nerves whose origin is close to the respiratory centre in the medulla oblongata. They are an adjuvant of voice, and like it their function is communication. (See Bell's Anatomy of Expression. Appendix by Alexander Shaw.)