188 EXPRESSION OF GRIEF: CHAP. VII. were rendered oblique, with their inner extremities puck- ered and swollen;—in the one child in a slight degree, in the other in a strongly marked manner. This differ- ence in the obliquity of the eyebrows apparently de- pended on a difference in their general mobility, and in the strength of the pyramidal muscles. In both these cases the eyebrows and forehead were acted on under the influence of a strong light, in precisely the same manner, in every characteristic detail, as under the in- fluence of grief or anxiety. Duchenne states that the pyramidal muscle of the nose is less under the control of the will than are the other muscles round the eyes. He remarks that the young man who could so well act on his grief-muscles, as well as on most of his other facial muscles, could not contract the pyramidals.5 This power, however, no doubt differs in different persons. The pyramidal mus- cle serves to draw down the skin of the forehead be- tween the eyebrows, together with their inner extremi- ties. The central fasciae of the frontal are the antago- nists of the pyramidal; and if the action of the latter is to be specially checked, these central fasciae must be contracted. So that with persons having powerful pyram- idal muscles, if there is under the influence of a bright light an unconscious desire to prevent the lowering of the eyebrows, the central fasciae of the frontal muscle must be brought into play; and their contraction, if suf- ficiently strong to overmaster the pyramidals, together with the contraction of the corrugator and orbicular muscles, will act in the manner just described on the eyebrows and forehead. "When children scream or cry out, they contract, as we know, the orbicular, corrugator, and pyramidal mus- 5 Mecanisme de la Phys. Hiimame, Album, p. 15.