OCR Text |
Show 92 MEANS OF EXPRESSION CrtAr. IV n1ind determine the shape of the mouth, or whether its shape is not detennined Ly independent causes, and the sonncl thus modified. \Vhen young infants cry they open their 1nouths 'videly, and this, no doubt, is necessary for pouring forth a full volume of sound; but the mouth then assumes, from a quite distinct cause, an ahnost quadrangular shape, depending, as will hereafter be explained, on the firm closing of the eyelids, and consequent drawing up of the upper lip. How far this square shape of the mouth modifies the wailing or crying sound, I a1n not prepared to say; but we know fron1 the researches of Helmholtz and others that the fonn of the cavity of the mouth and lips determines the nature and pitch of the vowel sounds which are produced. It will also be shown in a future chapter that, under the feeling of conte1npt or disgust, there is a tendency, frmn intelligible causes, to blow out of the mouth or nostrils, and this produces sounds like pooh or pish. vVhen any one is startled or suddenly astonished, there is an instantaneous tendency, likewise from an intelligible cause, namely, to be ready for prolonged exertion, to open the mouth widely, so as to draw a deep and rapid inspiration. When the next full expiration follows, the mouth is slightly closed, and the lips, from causes hereafter to be discussed, are somewhat protruded; and this form of the mouth, if the voice be at all exerted, produces, according to Heln1holtz, the sound of the vowel 0. Certainly a deep sound of a prolonged Oh! may be heard from a whole crowd of people immediately after witnessing any astonishing spectacle. If, together with surprise, pain be felt, there is a tendency to contract all the muscles of the body, including those of the face, and the lips will then be drawn back; and this will perhaps account for the sound becoming higher and CHAP. IV. IN ANIMALS. 93 assuming the character of Ah ! or Ach! As fear cau. es ull the muscles of the body to trembl , th voic naturally becomes tremulous, and at th san1 tin1e hu ky fr n1 the dryness of the n1outh owino· to tho sali varv bo-lancl. · ' b ~ failing to act.. 'Vhy the laughter of man a.nd the tittoriug of monkeys should be a rapidly reiterated sound, cannot be explained. During the utterance of these sounds, the mouth is trausversely elongated by the corners being drawn backward and upwartls; and of this fact an explanation will be atten1pt d in a future chapter. But the whole subject of tho differences of the sounds prod need under different states of the mind is so obscure, that I have succeeded in throwing hardly any light on it; and the remarks which I have made, baye but little significance. All the sounds hitherto noticed depend on the respiratory organs ; but sounds produced by wholly different means are likewise expressive. l{abbits sta1np loudly on the ground as a signal to their con1rades; and if a man knows how to do so properly, he may on a quiet evening hear the rabbits answering him all around. 'These auimals, as well as some others, also sta1np on the ground when n1ade angry. Por-cupines rattle their quills and vibrate \l; their tails when angered; and one be-l d . h. h }' l Fig 11. Sound-producing lave In t IS manner W en a l ve Sna {e qu1ns from the tttil of was placed in its compartment. The the Porcupine. quills on the tail are very different from tho e on the body : they are short, hollow, thin like a g o. c-1n:II, |